Custom 28 Relay Controller Board for Raspberry Pi 3

in #technology7 years ago

relay-board

Here is something interesting that you might like if you are into DIY stuff, IOT or crypto mining - a custom 28 relay control board designed for use with Raspberry Pi 3. The Pi has 28 pins that can be used as GPIO ones and thus can control up to 28 relays...


relay-board2

The board was designed for use with mining rigs and to be able to control up to 28 separate ones, though later on I have discovered that 3 out of the 28 GPIO pins on the Pi 3 have a bit of erratic behavior when turning on and off the power to the Raspberry, so essentially only 25 can be used problem free. The other 3 might be fixable with some more extra work figuring out why the Pi 3 turns them on and then off when power is applied.


relay-board3

A simple and effective solution to a problem as there are no affordable and commercially available relay boards that come with more than 16 relays (probably the demand for such is not big anyway). If you want to use the full potential of a RPi however you need a bit more relays and 25-28 seems to be just about the right number. Anyway 4 controllers can handle exactly 28 relays, so why not put them all... :)


If you have a question or want to add something, then please leave a comment below.


Did you like what you have just read? Check my other posts on steemit @cryptos

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Please explain on what type of mining rig I could use this and what crypto to mine? Thank you for the post buddy.

This is not for mining, it can be used for remote rebooting of mining rigs.

Specifically, it's used to connect to the ATX power switch pins on the motherboards of the mining rigs.

I know this is not for mining Cryptos, but you seem to know an awful lot about the hardware side of Mining. I'm currently planning on building a rig, so I may pick your brains in the future, if that's okay? Super interesting post, Upvoted, Resteemed and now Following.

What will you mining whit this ??? How did you make them?
I am interested in mining steem. :)

This is not for mining, it can be used for remote rebooting of mining rigs.

ok thanks

COOL! Your power problems can be resolved by powering the relay with a separate power supply. You may also need some kind of photodiode isolation to protect the pi and ensure 100% on/off functionality for all 28 relays. Are these solid-state relays? I've had the non-solid-state analog ones fail after a few thousand switches and only use solid-state now. Where did you buy it?

The Pi does not have a problem with the power with all 28 relays powered on, and the chance of having more than 1 on at a time is pretty slim in normal operating conditions. They are non-solid state relays, but the load is not going to be big, so they should be just fine. It is a custom design, not commercially available.

So what's the problem that causes you to only be able to use 25?

When powering on/off the Pi the GPIO pins 2, 3, 14 change state temporary... switching on and off the relays on them.

I didn't understand it!?

OIC, the only solution for that is to invert the signal at the hardware level. Such an inverter can simply be built with a single transistor and two resistors, or you can use a chip with six of them, like a 74HC04 (powered with 3,3V).

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it is too much costly here in Bangladesh!!

Привет ! Интересная информация , если ты посмотришь мой последний пост то тебе будет интересно , раз ты выкладываешь такую информацию ! Удачи !

Très bon article. Merci elle est très bien écrit par vous.
Est ce que vous pouvez faire un tour sur mon blog @zeryius s'il vous plaît merci.

Hello @cryptos how are you sir ???
I read your blog very interesting post.
Awesome sir for senior in technology.
I like your style in explanation about keyboard hardware. I dont have any question.
But I will give you something I can to do.
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Please xplain how to do it

Very cool device