From Newsgroup: comp.sys.raspberry-pi

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one
that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ? I'm not interested in a wireless
solution, as it is likely to be used in places where signals are not
reliable.

Thanks

Adrian
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From Newsgroup: comp.sys.raspberry-pi

On 18/01/2025 23:07, Adrian wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one that sits in line (between the device and the supply).  The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ?  I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

I've a similar thread in c.o.l.misc in particular. Although that's
headed 'smart plugs?' and looking for a wireless solution.

My own feeling is that the bigger the gap between mains and my
electronics, the better, and wireless is a good way for this.

I suspect off-the-shelf products, at least consumer-grade, will be
wireless. Might there be mileage in running network wires to local
wireless repeaters, then using wireless switches? Or use a
network-over-mains scheme?

Oh, and if you only need a PI for local control, with no networking,
don't forget the PI can be an AP and run a nearby wireless device
without a central router.

(FWIW I'm leaning towards the Shelly Plus Plug, at around £20. IIRC
there's a euro version too. It's the only one I've found that seems not
to need cloud servers.)
--
Mike Scott
Harlow, England

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From Newsgroup: comp.sys.raspberry-pi

Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

I don't understand the difference. Surely anything that's going to
turn something on/off needs to be "one that sits in line (between the
device and the supply)" doesn't it?

Do you mean (the ones that cost 100 Euros or more) something that
already has a mains plug and socket on it? I think they're going to
be expensive simply because they aren't much in demand. What 'the
world' wants is a WiFi connected switch and they're two a penny of
course.

Any suggestions on where to look ? I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

I think you'll probably have to bite the bullet and get a relay board
of some sort. Does it **have** to be USB? There's lots of quite neat
relay hats for the Pi.
--
Chris Green
·
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From Newsgroup: comp.sys.raspberry-pi

On 1/19/25 08:29, Mike Scott wrote:

On 1
(FWIW I'm leaning towards the Shelly Plus Plug, at around £20. IIRC
there's a euro version too. It's the only one I've found that seems not
to need cloud servers.)

<https://www.aliexpress.com/w/wholesale-athom-plug.html>

<https://www.mylocalbytes.com/products/smart-plug-pm>

I have some Shelly switches (not plugs), they are good too, just a bit
more expensive and not open-source firmware.

I wouldn't guarantee the electrical safety of any of them, but have run
a 2.4 KW heater off an Athom plug, for a short period of time, weeks (As opposed to continuously for 3-4 years for my freezer and fridge)
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From Newsgroup: comp.sys.raspberry-pi

On 1/18/25 23:07, Adrian wrote:

Any suggestions on where to look ?  I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

What do you mean not reliable? Active interference? Otherwise if you
have a device close enough for USB, it will be close enough for
Bluetooth or WiFi.
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From Newsgroup: comp.sys.raspberry-pi

Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

Why USB controlled? Is there a specific reason?

IMHO it's much easier (and cheaper) to use something like https://www.amazon.de/dp/B0054PSIDW?ref=ppx_yo2ov_dt_b_fed_asin_title ,
connect it to the PI via WLAN and control it via MQTT.
The PI can work as AP if there's no WLAN available.

HTH, Stefan
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From Newsgroup: comp.sys.raspberry-pi

On 18/01/2025 23:07, Adrian wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one that sits in line (between the device and the supply).  The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ?  I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

Thanks

Adrian

Pi Pico, transistor buffer and a big fat mains relay, plus code.
You can talk down the same USB you use to power it.

Less work and more cost - use a Pi with more USB onboard
--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher

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From Newsgroup: comp.sys.raspberry-pi

On 19/01/2025 09:04, Chris Green wrote:

Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one
that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

I don't understand the difference. Surely anything that's going to
turn something on/off needs to be "one that sits in line (between the
device and the supply)" doesn't it?

Do you mean (the ones that cost 100 Euros or more) something that
already has a mains plug and socket on it? I think they're going to
be expensive simply because they aren't much in demand. What 'the
world' wants is a WiFi connected switch and they're two a penny of
course.

Any suggestions on where to look ? I'm not interested in a wireless
solution, as it is likely to be used in places where signals are not
reliable.

I think you'll probably have to bite the bullet and get a relay board
of some sort. Does it **have** to be USB? There's lots of quite neat
relay hats for the Pi.

They aren't especially able to handle 230V at sane currents.

I made my own board up. Featuring onboard PSU and mains chokes and
filers and a fuse, a 13A capable relay and a pi PICO. Also has an
optional temperature sensor hooked up to the ADC

Can send you the Gerbers if interested
--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels




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From Newsgroup: comp.sys.raspberry-pi

On 19/01/2025 11:25, Pancho wrote:

On 1/18/25 23:07, Adrian wrote:

Any suggestions on where to look ?  I'm not interested in a wireless
solution, as it is likely to be used in places where signals are not
reliable.

What do you mean not reliable?  Active interference? Otherwise if you
have a device close enough for USB, it will be close enough for
Bluetooth or WiFi.

Sadly that is not a given. You wont get much wifi to a board inside a
tin box, but you could make a hole for a USB cable...

serial over USB can probably do a hundred meters at a pinch, too.
--
Microsoft : the best reason to go to Linux that ever existed.

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From Newsgroup: comp.sys.raspberry-pi

In message <vmid5v$20nh3$1@dont-email.me>, Mike Scott <usenet.16@scottsonline.org.uk.invalid> writes

On 18/01/2025 23:07, Adrian wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can >>connect to a PI to turn a mains power supply on and off.
I've done a bit of digging around on the net, and the options seem
to fall into two categories, either a relay device which means having >>rewire the device (which I'd rather avoid), priced around 30Euros or
one that sits in line (between the device and the supply).  The latter >>appears to be in excess of 100Euros, which is considerably more than I >>want to pay.
Any suggestions on where to look ?  I'm not interested in a wireless >>solution, as it is likely to be used in places where signals are not >>reliable.

Oh, and if you only need a PI for local control, with no networking,
don't forget the PI can be an AP and run a nearby wireless device
without a central router.

The Pi already exists, and is connected to my home LAN (Ethernet). A
range of a few feet should work for WiFi (if I used the PI as an AP),
but home WiFi is at best flaky where I want to run this, hence why the
Pi is on Ethernet.

(FWIW I'm leaning towards the Shelly Plus Plug, at around £20. IIRC
there's a euro version too. It's the only one I've found that seems not
to need cloud servers.)

£20 is nearer the make for what my soggy finger in the air suggested
would be a sensible price, the LocalBytes site mentioned elsewhere in
the thread comes out at £12.75. Although I quoted prices in euros, I'm
in the UK, but all the items I'd found so far were priced in euros.

Thanks

Adrian
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From Newsgroup: comp.sys.raspberry-pi

In message <6pru5l-oju1.ln1@q957.zbmc.eu>, Chris Green <cl@isbd.net>
writes

Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one
that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

I don't understand the difference. Surely anything that's going to
turn something on/off needs to be "one that sits in line (between the
device and the supply)" doesn't it?

The cheaper option involves cutting the plug off the item, and hard
wiring it into the board. I've got two problems with that. Firstly, it
means that I can't readily reuse that item elsewhere as I'd have to
replace the plug (a bit of a faff if it is temporary move), and secondly
if I'm trying to control something fed via a wall wart then it gets
messy unless I leave the wall wart powered all the time (which I'd
rather not do), and switch between it and the device.

Do you mean (the ones that cost 100 Euros or more) something that
already has a mains plug and socket on it? I think they're going to
be expensive simply because they aren't much in demand. What 'the
world' wants is a WiFi connected switch and they're two a penny of
course.

Trust me to be awkward :-)

Any suggestions on where to look ? I'm not interested in a wireless
solution, as it is likely to be used in places where signals are not
reliable.

I think you'll probably have to bite the bullet and get a relay board
of some sort. Does it **have** to be USB? There's lots of quite neat
relay hats for the Pi.

No, but USB seemed to be the most likely solution as it works equally as
well for Non-Pi situations. Power may also be an issue. My initial requirement is for a low power device, which (without checking the
numbers) might be within the capability of running directly from the Pi,
but I can foresee needs where that won't be the case, so a standard
solution has its attractions.

Thanks

Adrian
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From Newsgroup: comp.sys.raspberry-pi

In message <vmitka$2719a$11@dont-email.me>, The Natural Philosopher <tnp@invalid.invalid> writes

On 19/01/2025 11:25, Pancho wrote:

On 1/18/25 23:07, Adrian wrote:

Any suggestions on where to look ?  I'm not interested in a wireless >>>solution, as it is likely to be used in places where signals are not >>>reliable.

What do you mean not reliable?  Active interference? Otherwise if
you have a device close enough for USB, it will be close enough for >>Bluetooth or WiFi.

Sadly that is not a given. You wont get much wifi to a board inside a
tin box, but you could make a hole for a USB cable...

serial over USB can probably do a hundred meters at a pinch, too.

By WiFi, in this case, I'm referring to my home WLAN.

This isn't a new install, I'm looking at extending what I do with that particular Pi. I've tried using the Pi on WiFi in that location and it
can disappear off the network for prolonged periods of time. Likewise
if I'm stood next to it with my mobile, it has reverted to 4G rather
than WiFi for data, so the location is not really practical for a WiFi
based solution.

Using the Pi as an AP could work, that isn't something I've tried yet.
The Pi lives in a plastic IP55 box, so I would hoped that short range
(couple of feet) WiFi / Bluetooth would work.

Thanks

Adrian
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From Newsgroup: comp.sys.raspberry-pi

On 1/19/25 14:13, Adrian wrote:

In message <vmitka$2719a$11@dont-email.me>, The Natural Philosopher <tnp@invalid.invalid> writes

On 19/01/2025 11:25, Pancho wrote:

On 1/18/25 23:07, Adrian wrote:

Any suggestions on where to look ?  I'm not interested in a wireless >>>> solution, as it is likely to be used in places where signals are not
reliable.

 What do you mean not reliable?  Active interference? Otherwise if
you have a device close enough for USB, it will be close enough for
Bluetooth or WiFi.

Sadly that is not a given. You wont get much wifi to a board inside a
tin box, but you could make a hole for a USB cable...

serial over USB can probably do a hundred meters at a pinch, too.

By WiFi, in this case, I'm referring to my home WLAN.

This isn't a new install, I'm looking at extending what I do with that particular Pi.  I've tried using the Pi on WiFi in that location and it
can disappear off the network for prolonged periods of time.  Likewise
if I'm stood next to it with my mobile, it has reverted to 4G rather
than WiFi for data, so the location is not really practical for a WiFi
based solution.

Using the Pi as an AP could work, that isn't something I've tried yet.
The Pi lives in a plastic IP55 box, so I would hoped that short range (couple of feet) WiFi / Bluetooth would work.

A slight caveat, I don't want to mislead, I use WiFi.

I see some of the plugs use Bluetooth, my older ones are WiFi only. I
also think some of the plugs that advertise Bluetooth may use it only
for configuration as opposed to a primary communication method. If you
want to go that route, read the spec carefully.

My Wifi plugs are reliable, but my house had good coverage from multiple
Wifi access points (Mesh/Fast Roaming). Cheap stuff, but it works better
than anything I had previously.


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From Newsgroup: comp.sys.raspberry-pi

In message <TjgqpoLGRDjnFwvW@ku.gro.lloiff>
Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to fall into two categories, either a relay device which means having to rewire
the device (which I'd rather avoid), priced around 30Euros or one that
sits in line (between the device and the supply). The latter appears to
be in excess of 100Euros, which is considerably more than I want to pay.

Any suggestions on where to look ? I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

I did a bit of searching around. AliExpress sell various models of
USB mains-rated relay boards. Various models offer 5V, 12V or 24V
operation. I see from a later posting that your RPi is in an IP55
plastic box, so I'm jumping to the conclusion that you're happy with
a bit of DIY to turn it from a board into a solution.

If I were doing it this way, I think I'd go for a 12V powered board
and have a separate PSU, rather than burden the RPi's supply further
as many people have problems that are traceable to inadequate power
supplies.

It sounds like you may have to build a USB library for the relay
boards - I don't know.

If I were doing the overall job that you're doing, I wouldn't use
USB, I'd use a GPIO pin to switch a different relay board on/off.
Much easier (and I've done lots of work on USB firmware and drivers).

David
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From Newsgroup: comp.sys.raspberry-pi

Adrian <bulleid@ku.gro.lioff> wrote:

In message <6pru5l-oju1.ln1@q957.zbmc.eu>, Chris Green <cl@isbd.net>
writes

Adrian <bulleid@ku.gro.lioff> wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one >> that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

I don't understand the difference. Surely anything that's going to
turn something on/off needs to be "one that sits in line (between the >device and the supply)" doesn't it?

The cheaper option involves cutting the plug off the item, and hard
wiring it into the board. I've got two problems with that. Firstly, it means that I can't readily reuse that item elsewhere as I'd have to
replace the plug (a bit of a faff if it is temporary move), and secondly
if I'm trying to control something fed via a wall wart then it gets
messy unless I leave the wall wart powered all the time (which I'd
rather not do), and switch between it and the device.

You could just chop up a mains extension cable and insert your relay in the middle.

No, but USB seemed to be the most likely solution as it works equally as well for Non-Pi situations. Power may also be an issue. My initial requirement is for a low power device, which (without checking the
numbers) might be within the capability of running directly from the Pi,
but I can foresee needs where that won't be the case, so a standard
solution has its attractions.

The advantage of wireless is you get isolation for free, so you don't need
to worry about mains backfeeding into the Pi, which makes construction
cheaper. It doesn't need to be wifi, there are also options using 433MHz 'remote control' frequency, which is point to point and longer range:

https://energenie4u.co.uk/catalogue/product/ENER002-2PI https://www.ebay.co.uk/itm/396124241128

also with power measurement: https://energenie4u.co.uk/catalogue/product/ENER002-2PI-RT

The transmitter speaks GPIO and there's Python code to control them from the Pi.

Theo
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From Newsgroup: comp.sys.raspberry-pi

In message <ASw*Me14z@news.chiark.greenend.org.uk>, Theo <theom+news@chiark.greenend.org.uk> writes

The advantage of wireless is you get isolation for free, so you don't need
to worry about mains backfeeding into the Pi, which makes construction >cheaper. It doesn't need to be wifi, there are also options using 433MHz >'remote control' frequency, which is point to point and longer range:

https://energenie4u.co.uk/catalogue/product/ENER002-2PI >https://www.ebay.co.uk/itm/396124241128

also with power measurement: >https://energenie4u.co.uk/catalogue/product/ENER002-2PI-RT

The transmitter speaks GPIO and there's Python code to control them from the >Pi.

Thanks, that looks interesting.

Adrian
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From Newsgroup: comp.sys.raspberry-pi

Adrian,

... the options seem to fall into two categories, either a relay device which means having to rewire the device (which I'd rather avoid), priced around 30Euros or one that sits in line (between the device and the
supply)

Whut ? As others have already mentioned, you could take a short extension cord and put the relais* in that cord. Makes it reusable too.

* also consider a solid-state relais.

Also, you say USB controlled. How do you imagine that ? As some kind of special USB device (for which it is hard to find a driver) ?

Perhaps consider a simple USB-to-serial thingly*, where you can use the DTR line to signal the relais board to switch on. After that you can use the
RPi build-in serial API to switch the relais.

* I would strongly suggest to use one of RPi's gazillion I/O pins for it,
but as you specifically mentioned USB controlled ...

The only thing you will need to do (and which costs money) is to put the relais (and the USB-to-signal-line thingamagochy ?) in a shielding plastic box. 220 is lethal even when you touch it by accident. :-) And make sure the 220v and the relais-driving low-voltage electronics are well seperated. Your RPi doesn't like 220v either. :-o

Regards,
Rudy Wieser


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From Newsgroup: comp.sys.raspberry-pi

On 19/01/2025 at 19:24, R.Wieser wrote:

Adrian,

... the options seem to fall into two categories, either a relay device
which means having to rewire the device (which I'd rather avoid), priced
around 30Euros or one that sits in line (between the device and the
supply)

Whut ? As others have already mentioned, you could take a short extension cord and put the relais* in that cord. Makes it reusable too.

* also consider a solid-state relais.

Also, you say USB controlled. How do you imagine that ? As some kind of special USB device (for which it is hard to find a driver) ?

As I have said previously, it's easy. E.g. https://www.amazon.co.uk/Control-Intelligent-Channel-Controller-Support-default/dp/B07PWPF2DT
Load 'usbrelay' to control (apt-get install usbrelay')

Perhaps consider a simple USB-to-serial thingly*, where you can use the DTR line to signal the relais board to switch on. After that you can use the
RPi build-in serial API to switch the relais.

* I would strongly suggest to use one of RPi's gazillion I/O pins for it,
but as you specifically mentioned USB controlled ...

The only thing you will need to do (and which costs money) is to put the relais (and the USB-to-signal-line thingamagochy ?) in a shielding plastic box. 220 is lethal even when you touch it by accident. :-) And make sure the 220v and the relais-driving low-voltage electronics are well seperated. Your RPi doesn't like 220v either. :-o

Regards,
Rudy Wieser

--
Chris Elvidge, England
I CANNOT ABSOLVE SINS

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From Newsgroup: comp.sys.raspberry-pi

Chris,

Also, you say USB controlled. How do you imagine that ? As some kind of
special USB device (for which it is hard to find a driver) ?

As I have said previously, it's easy. E.g. https://www.amazon.co.uk/Control-Intelligent-Channel-Controller-Support-default/dp/B07PWPF2DT

Whohoo! They actually did it, a hobby-level relay driven by USB. I'm
amazed. And I see there are no drivers needed as long as its used with
Win XP or 7. I stand corrected.

Load 'usbrelay' to control (apt-get install usbrelay')

One question though : (where and) how did you find that Linux driver ?


Wait, what ?

Under "Technical details" :

Voltage ?5 Volts
Wattage ?50 watts

Something is fishy there ... and I only now realize that I do not see any mentioning for which voltage its output is rated. If the above is correct than they have rated it for 5 volts (5V x 10A = 50W), not 220 ...

Do *NOT* use stuff above its voltage rating. The electrical track
seperation between the (low voltage) driving electronic and (high voltage) output circuits might not be large enough.

Regards,
Rudy Wieser


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From Newsgroup: comp.sys.raspberry-pi

On 20/01/2025 06:26, R.Wieser wrote:

Do*NOT* use stuff above its voltage rating.

Look at the damn pictures of the relays, you can see the ratings and the
model number used.

SR-05VDC-SL-C

5V DC SONGLE Power Relay SRD-05VDC-SL-C (5 Pin mit NC / NO)
Contact form: 1a, 1b, 1c
Rated load: 10A 250VAC/28VDC,10A 125VAC/28VDC,10A 125VAC/28VDC
Contact resistance: <= 100 mOhm
Electrical life: 100,000
Mechanical life: 10,000,000
Coil rated voltage: 3-48VDC
Coil power: 0.36W, 0.45W
Coil pick-up voltage: <= 75%
Coil drop-out voltage: >=10%
Ambient temperature: -25 degrees Celsius to +70 degrees Celsius
Coil and contacts:1500VAC/min
Contact and contacts: 1000VAC/min
Insulation resistance: >=100M (ohm)

https://www.play-zone.ch/de/5v-dc-power-relay-songle-srd-5vdc-sl-c.html

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From Newsgroup: comp.sys.raspberry-pi

On 20/01/2025 07:41, mm0fmf wrote:

On 20/01/2025 06:26, R.Wieser wrote:

Do*NOT*  use stuff above its voltage rating.

Look at the damn pictures of the relays, you can see the ratings and the model number used.

SR-05VDC-SL-C

    5V DC SONGLE Power Relay SRD-05VDC-SL-C  (5 Pin mit NC / NO)
    Contact form: 1a, 1b, 1c
    Rated load: 10A 250VAC/28VDC,10A 125VAC/28VDC,10A 125VAC/28VDC
    Contact resistance: <= 100 mOhm
    Electrical life: 100,000
    Mechanical life: 10,000,000
    Coil rated voltage: 3-48VDC
    Coil power: 0.36W, 0.45W
    Coil pick-up voltage: <= 75%
    Coil drop-out voltage: >=10%
    Ambient temperature: -25 degrees Celsius to +70 degrees Celsius
    Coil and contacts:1500VAC/min
    Contact and contacts: 1000VAC/min
    Insulation resistance: >=100M (ohm)

https://www.play-zone.ch/de/5v-dc-power-relay-songle-srd-5vdc-sl-c.html

I'm using these (relays) to control my central heating from a Pi Zero.
They are OK

Driving a relay via a transistor is very simple and the code is minimal
--
No Apple devices were knowingly used in the preparation of this post.

--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi


"mm0fmf" <none@invalid.com> wrote in message news:vmkunu$2v2um$1@dont-email.me...

On 20/01/2025 06:26, R.Wieser wrote:

Do*NOT* use stuff above its voltage rating.

Look at the damn pictures of the relays, you can see the ratings and the model number used.

You mean you didn't follow the "See more product details" under "About this item" link ?

Ah, there is also a "product parameters" paragraph (down the page).

And no, the relais themselves being specced for 220V doesn't mean shite when the board its on has its low- and high-voltage tracks too close together.

Regards,
Rudy Wieser


--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 20/01/2025 06:26, R.Wieser wrote:

Do*NOT* use stuff above its voltage rating.

news:vmkunu$2v2um$1@dont-email.me...
"mm0fmf" <none@invalid.com> wrote in message

Look at the damn pictures of the relays, you can see the ratings and the
model number used.

On 2025-01-20, R.Wieser <address@is.invalid> wrote:

You mean you didn't follow the "See more product details" under "About this item" link ?

Ah, there is also a "product parameters" paragraph (down the page).

And no, the relais themselves being specced for 220V doesn't mean shite when the board its on has its low- and high-voltage tracks too close together.

The high-voltage tracks are MUCH fatter than the low voltage tracks on
the PCB, as you can clearly see in the photo of the underside of the
board, and high and low voltage sections of the board are well separated.
My main concern would be the high voltage tracks heating up and
deliminating when the current gets really high, but I think they are OK
for 10A. Looks pretty good to me.
--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

Lars,

The high-voltage tracks are MUCH fatter than the low voltage tracks
on the PCB, as you can clearly see in the photo of the underside of
the board,

Thick tracks are current, not voltage related.

And by the way, I didn't see those images the first time around : I've got
all third-party (domain) content blocked by default.

and high and low voltage sections of the board are well separated.

How many low-voltage lines do you seee going to the relays at the underside
? I see just a single one. And that means the topside has the rest,
which I can't see.

And do remember there is a 30 Watts rating mentioned. Which one should we believe ? That one, or the other, 2200 Watts one ?

I can guess a bit, but I'd rather not when letal voltages are in play. :-|

Regards,
Rudy Wieser


--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 18/01/2025 23:07, Adrian wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

What you want is a mains rated GPIO compatible relay card. All good Pi stockists carry them, and they are available in any thing from a single
relay single pole, up to 4 or more dual pole units. You'll want to get a
small electric junction box to put the relay and the spliced cable into.

---druck
--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 19/01/2025 14:01, Adrian wrote:

The cheaper option involves cutting the plug off the item, and hard
wiring it into the board.  I've got two problems with that.  Firstly, it means that I can't readily reuse that item elsewhere as I'd have to
replace the plug (a bit of a faff if it is temporary move),

The easy solution to that is to get a short single socket mains
extension cable and splice the relay into that. It's then usable with
any device.

and secondly
if I'm trying to control something fed via a wall wart then it gets
messy unless I leave the wall wart powered all the time (which I'd
rather not do), and switch between it and the device.

If it's got a wall wart, it's far better to switch the low voltage side.
You can then use a less expensive non mains rated relay. Most wall wart devices have a connector of some sort, so make an extension lead to
splice the relay into. If it is a hard wired one, you'll have to cut the
cable at some point, but fit some 5.5x2.1mm jack connectors so you can
rejoin it without the relay if needed.

---druck
--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On Sat, 18 Jan 2025 23:07:50 +0000, Adrian wrote:

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or one that sits in line (between the device and the supply). The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ? I'm not interested in a wireless solution, as it is likely to be used in places where signals are not reliable.

Thanks

Adrian

No need to rewire the end device to use a relay controller. Just wire up
a simple intermediate between the relay and the controlled device. i.e.
add a plug and outlet to the relay. Or buy a pre-built one:

Low voltage controlled (about $40) https://dlidirect.com/products/iot-power-relay

Ethernet controlled (about $80) https://www.amazon.com/ezOutlet5-Internet-WiFi-Reboot-Switch/dp/B0861NX6H2/
--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

In message <TjgqpoLGRDjnFwvW@ku.gro.lloiff>, Adrian
<bulleid@ku.gro.lioff> writes

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or
one that sits in line (between the device and the supply). The latter >appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ? I'm not interested in a wireless >solution, as it is likely to be used in places where signals are not >reliable.

Thanks

Adrian

OP here with a follow up.

After some ruminating, I decided to give the Local Bytes Smart plug a
try. I've got it happily working now, although I did have to install
(yet) another Pi to act as the control hub (Home Assistant if anyone is interested). I'm now waiting for a fresh delivery of a Pi3 to install
as a WiFi AP (the Pis in the locality are all Pi2).

One useful feature of the Local Bytes offering is that you can see to
power being consumed by the device it is controlling (although mine
suggests that I'm on 245V), but I've yet to work out how to access that
via a command line, rather than web interface.

Thanks again for the suggestions.

Adrian
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From Newsgroup: comp.sys.raspberry-pi

On 2/10/25 14:42, Adrian wrote:

In message <TjgqpoLGRDjnFwvW@ku.gro.lloiff>, Adrian
<bulleid@ku.gro.lioff> writes

I'm looking for a USB controlled mains switch (230V AC) that I can
connect to a PI to turn a mains power supply on and off.

I've done a bit of digging around on the net, and the options seem to
fall into two categories, either a relay device which means having to
rewire the device (which I'd rather avoid), priced around 30Euros or
one that sits in line (between the device and the supply).  The latter
appears to be in excess of 100Euros, which is considerably more than I
want to pay.

Any suggestions on where to look ?  I'm not interested in a wireless
solution, as it is likely to be used in places where signals are not
reliable.

Thanks

Adrian

OP here with a follow up.

After some ruminating, I decided to give the Local Bytes Smart plug a
try. I've got it happily working now, although I did have to install
(yet) another Pi to act as the control hub (Home Assistant if anyone is interested).  I'm now waiting for a fresh delivery of a Pi3 to install
as a WiFi AP (the Pis in the locality are all Pi2).

One useful feature of the Local Bytes offering is that you can see to
power being consumed by the device it is controlling (although mine
suggests that I'm on 245V), but I've yet to work out how to access that
via a command line, rather than web interface.

Thanks again for the suggestions.

Adrian

Did you opt for ESPHome or Tasmota firmware?

I use Tasmota, but I use Domoticz rather than Home Assistant. From what
I read ESPHome is tailored for Home Assistant and uses REST API rather
than MMQT like Tasmota.

A Pi4 can handle a lot of different services on the same machine,
installed in Docker Containers. So you don't necessarily need lots of
Pis. If the Pi4 isn't enough, there are more powerful Pis.


--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

In message <voibvg$2bloc$1@dont-email.me>, Pancho
<Pancho.Jones@proton.me> writes

OP here with a follow up.
After some ruminating, I decided to give the Local Bytes Smart plug
a try. I've got it happily working now, although I did have to install >>(yet) another Pi to act as the control hub (Home Assistant if anyone
is interested).  I'm now waiting for a fresh delivery of a Pi3 to
install as a WiFi AP (the Pis in the locality are all Pi2).
One useful feature of the Local Bytes offering is that you can see
to power being consumed by the device it is controlling (although mine >>suggests that I'm on 245V), but I've yet to work out how to access
that via a command line, rather than web interface.
Thanks again for the suggestions.
Adrian

Did you opt for ESPHome or Tasmota firmware?

Tasmota. No particular reason.

I use Tasmota, but I use Domoticz rather than Home Assistant. From what
I read ESPHome is tailored for Home Assistant and uses REST API rather
than MMQT like Tasmota.

A Pi4 can handle a lot of different services on the same machine,
installed in Docker Containers. So you don't necessarily need lots of
Pis. If the Pi4 isn't enough, there are more powerful Pis.

Machine power isn't likely to be an issue. HA suggest a Pi4 as a
suitable host, but I didn't have a spare one, so I installed it on a
Pi3. However, as I need to set up a WiFi Access point, and that needs

=Pi3 I had to go shopping. I hope that for what I'm going to be using

it for (apart from the AP), a Pi3 will be more than enough.

So far as I've been able to find out, HA is only installed as an image
on the SD card (using the RPI Imager), rather than manually installed on
an existing Pi image (e.g. apt install ...), so that means that the Pi
can only be used for what HA allows you to do. Therefore, one downside
(for me) with HA is that I don't seem to be able to gain SSH access to
the PI. I can access it via the web interface, and I can install a ZSH
shell on it, but that is in (I think) a Docker Container. What I would
like to be able to do, which I can with my other Pis, is to run regular
health check stuff, CPU temp, free memory, free card space that sort of
stuff. I can do that from the Docker Container, but I can't set up a
cron job to do it, and I haven't even tried getting it to email me a
daily summary.

A quick look at Domoticz suggests that it will allow me to do my own monitoring, so that could be worth looking at in due course.


Thanks for the follow up.

Adrian
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From Newsgroup: comp.sys.raspberry-pi

On 2025-02-10, Adrian <bulleid@ku.gro.lioff> wrote:

interested). I'm now waiting for a fresh delivery of a Pi3 to install
as a WiFi AP (the Pis in the locality are all Pi2).

I hope you plan to run other services on the Pi3 as well - used purely as an access point, the pi is not the best choice. For a low number of stations
and low throughput, it works, but dedicated wireless access points have
better wifi hardware (and probably cost less).

cu
Michael
--
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--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

In message <slrnvqq2e0.sal.news-1513678000@a-tuin.ms.intern>, Michael Schwingen <news-1513678000@discworld.dascon.de> writes

On 2025-02-10, Adrian <bulleid@ku.gro.lioff> wrote:

interested). I'm now waiting for a fresh delivery of a Pi3 to install
as a WiFi AP (the Pis in the locality are all Pi2).

I hope you plan to run other services on the Pi3 as well - used purely as an >access point, the pi is not the best choice. For a low number of stations >and low throughput, it works, but dedicated wireless access points have >better wifi hardware (and probably cost less).

Indeed I do. I'll see how it goes, and if it doesn't work out, then I
can turn the WiFi off, and it can carry on with its other duties. My expectation is that it will be talking to at the most three Smart
Switches, I'm unlikely to be using it for (e.g.) Internet access from a
phone.


Adrian
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Adrian <bulleid@ku.gro.lioff> wrote:

So far as I've been able to find out, HA is only installed as an image
on the SD card (using the RPI Imager), rather than manually installed on
an existing Pi image (e.g. apt install ...), so that means that the Pi
can only be used for what HA allows you to do. Therefore, one downside
(for me) with HA is that I don't seem to be able to gain SSH access to
the PI. I can access it via the web interface, and I can install a ZSH shell on it, but that is in (I think) a Docker Container. What I would
like to be able to do, which I can with my other Pis, is to run regular health check stuff, CPU temp, free memory, free card space that sort of stuff. I can do that from the Docker Container, but I can't set up a
cron job to do it, and I haven't even tried getting it to email me a
daily summary.

HA can be installed in several ways.

The normal HAOS install has a series of Docker containers that are
orchestrated by HA, and to do that it uses the whole Pi. SSH access is to inside the primary container, rather than the native system.

It's possible to install HA via Docker onto a regular RaspiOS system. That means you have access to the outside system, but the downside is that HA
can't manage its own containers. For example, some plugins come in separate containers and you'd have to install those by using Docker, rather than clicking a button in HAOS and have it spin them up itself.

(If you pass through the Docker socket to the primary HA container, it's possible it can then orchestrate other containers without using HAOS. I haven't tried that)

There's also a 'just install HA using Python' method in which case there's
no Docker containers, but that means upgrading is up to you doing it by
hand. HA changes pretty regularly so that method isn't recommended.

Finally, if you were on x86 you can install HAOS in a VM which is just like having it take over the whole machine only inside a VM. You could run a
HAOS image using KVM on a Pi but I'm not sure how smooth that would be.

Theo
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From Newsgroup: comp.sys.raspberry-pi

In message <eSD*zI36z@news.chiark.greenend.org.uk>, Theo <theom+news@chiark.greenend.org.uk> writes

HA can be installed in several ways.

<big snip for brevity>

Thanks for the extra info. More to digest when I get a chance.

Adrian
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From Newsgroup: comp.sys.raspberry-pi

On 2/13/25 12:15, Theo wrote:

Adrian <bulleid@ku.gro.lioff> wrote:

So far as I've been able to find out, HA is only installed as an image
on the SD card (using the RPI Imager), rather than manually installed on
an existing Pi image (e.g. apt install ...), so that means that the Pi
can only be used for what HA allows you to do. Therefore, one downside
(for me) with HA is that I don't seem to be able to gain SSH access to
the PI. I can access it via the web interface, and I can install a ZSH
shell on it, but that is in (I think) a Docker Container. What I would
like to be able to do, which I can with my other Pis, is to run regular
health check stuff, CPU temp, free memory, free card space that sort of
stuff. I can do that from the Docker Container, but I can't set up a
cron job to do it, and I haven't even tried getting it to email me a
daily summary.

HA can be installed in several ways.

I had no idea why I chose Domoticz over HA, it was a few years ago, but
you present a compelling argument.

My rpi4 Domoticz install is a 12 line docker-compose.yml.

I already had MQTT.

Domoticz works, lets me switch things on and off, immediately or
scheduled, and provides me with historical usage graphs. Which is all I
really want.

Dunno if it relates to you, but I had a similar SSH problem.

I had a Gitea Container (a pretty UI git repo manager) needing to
reserve the standard SSH port for git to work, this took over the host
rPi host standard SHH port. My solution was to assign the Gitea
container its own LAN IP address using a Docker Macvlan network drive,
thus the Gitea container and the host rPI could each use the default SSH
port as they had distinct IPs.


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From Newsgroup: comp.sys.raspberry-pi

In message <vol5gc$2v89p$1@dont-email.me>, Pancho <Pancho.Jones@protonmail.com> writes

On 2/13/25 12:15, Theo wrote:

Adrian <bulleid@ku.gro.lioff> wrote:

So far as I've been able to find out, HA is only installed as an image
on the SD card (using the RPI Imager), rather than manually installed on >>> an existing Pi image (e.g. apt install ...), so that means that the Pi
can only be used for what HA allows you to do. Therefore, one downside
(for me) with HA is that I don't seem to be able to gain SSH access to
the PI. I can access it via the web interface, and I can install a ZSH
shell on it, but that is in (I think) a Docker Container. What I would
like to be able to do, which I can with my other Pis, is to run regular
health check stuff, CPU temp, free memory, free card space that sort of
stuff. I can do that from the Docker Container, but I can't set up a
cron job to do it, and I haven't even tried getting it to email me a
daily summary.

HA can be installed in several ways.

I had no idea why I chose Domoticz over HA, it was a few years ago, but
you present a compelling argument.

My rpi4 Domoticz install is a 12 line docker-compose.yml.

I already had MQTT.

Domoticz works, lets me switch things on and off, immediately or
scheduled, and provides me with historical usage graphs. Which is all I >really want.

I've managed to get a PI to ask HA to turn my switch on and off, but
I've not been able to get the PI to read the data used to generate the
graphs, which I'd like to be able to do. It would be useful to at least
know if the switch is already on before I try to turn it on again !
Bonus points for being able to get the power consumption of the device
it is controlling.

Dunno if it relates to you, but I had a similar SSH problem.

I had a Gitea Container (a pretty UI git repo manager) needing to
reserve the standard SSH port for git to work, this took over the host
rPi host standard SHH port. My solution was to assign the Gitea
container its own LAN IP address using a Docker Macvlan network drive,
thus the Gitea container and the host rPI could each use the default
SSH port as they had distinct IPs.

Until installing HA, I've never (knowingly) had any dealings with
Docker.

Adrian
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On 2/13/25 17:04, Adrian wrote:

In message <vol5gc$2v89p$1@dont-email.me>, Pancho <Pancho.Jones@protonmail.com> writes

On 2/13/25 12:15, Theo wrote:

Adrian <bulleid@ku.gro.lioff> wrote:

So far as I've been able to find out, HA is only installed as an image >>>> on the SD card (using the RPI Imager), rather than manually
installed on
an existing Pi image (e.g. apt install ...), so that means that the Pi >>>> can only be used for what HA allows you to do.  Therefore, one downside >>>> (for me) with HA is that I don't seem to be able to gain SSH access to >>>> the PI.  I can access it via the web interface, and I can install a ZSH >>>> shell on it, but that is in (I think) a Docker Container.  What I would >>>> like to be able to do, which I can with my other Pis, is to run regular >>>> health check stuff, CPU temp, free memory, free card space that sort of >>>> stuff.  I can do that from the Docker Container, but I can't set up a >>>> cron job to do it, and I haven't even tried getting it to email me a
daily summary.

 HA can be installed in several ways.

I had no idea why I chose Domoticz over HA, it was a few years ago,
but you present a compelling argument.

My rpi4 Domoticz install is a 12 line docker-compose.yml.

I already had MQTT.

Domoticz works, lets me switch things on and off, immediately or
scheduled, and provides me with historical usage graphs. Which is all
I really want.

I've managed to get a PI to ask HA to turn my switch on and off, but
I've not been able to get the PI to read the data used to generate the graphs, which I'd like to be able to do.  It would be useful to at least know if the switch is already on before I try to turn it on again !
Bonus points for being able to get the power consumption of the device
it is controlling.

Try Domoticz, it is supposed to be much simpler than HA. Not as feature
rich as HA, but maybe a better fit for a simple home setup. (Caveat:
I've never used HA).

Dunno if it relates to you, but I had a similar SSH problem.

I had a Gitea Container (a pretty UI git repo manager) needing to
reserve the standard SSH port for git to work, this took over the host
rPi host standard SHH port. My solution was to assign the Gitea
container its own LAN IP address using a Docker Macvlan network drive,
thus the Gitea container and the host rPI could each use the default
SSH port as they had distinct IPs.

That should be Macvlan network driver, not drive.

Until installing HA, I've never (knowingly) had any dealings with Docker.

Docker is brilliant! If they had had it when I was working, I wouldn't
have needed to wear my brown trousers every release day, at least not so
much :-). Although, I'm sure the bright young things of today will have introduced new complexity, so it is still easy to mess things up.

Nowadays, for me, it can make installing third party software simple, as opposed to a nightmare of conflicting environment.
--- Synchronet 3.20c-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

In message <volamj$2v89p$2@dont-email.me>, Pancho <Pancho.Jones@protonmail.com> writes

Try Domoticz, it is supposed to be much simpler than HA. Not as feature
rich as HA, but maybe a better fit for a simple home setup. (Caveat:
I've never used HA).

It's on the tuit list.

Docker is brilliant! If they had had it when I was working, I wouldn't
have needed to wear my brown trousers every release day, at least not
so much :-). Although, I'm sure the bright young things of today will
have introduced new complexity, so it is still easy to mess things up.

Nowadays, for me, it can make installing third party software simple,
as opposed to a nightmare of conflicting environment.

From what little I know of it, I can see the attraction of using it for complex stuff, but I'm not convinced that it isn't a bit OTT for simpler stuff. A problem is deciding when simple becomes complex.

Adrian
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