Does anyone know if there is a way to bind a shift register?
I explain myself: I’m talking about using 3 GPIO pins (Latch, CLock, Data) to command a shift register board (based on 74HC595), in order to command more and more pins (in my precise situation, some 8Ch Relay Boards).
Or do you think there is a different way to achieve the same result?
No. To control a chain of 8-16Ch Relay Board for 220V. In my case, 4x 8Ch Relay Board, to be controlled by only 3 pins, and some input boards to be readed by 3 pins. At the moment, I control and read them with Arduino, but I want to switch everything to a sole RaspberryPi.
As you wrote, I can obviously use GPIO binding and code everything from scratch. But, noting that someone else has needed this before, perhaps there is a binding just coded and ready to use.
Unless your planning to run copious amounts of wire from a single location I would recommend wireless (Esp8266) or bluetooth (Esp32) for TX/RX and relay switching.
Are these relays 12/24v switching power? If so the relays with an Arduino or RPI will need to use something like a transistor as they are 5 and 3 volts output only.
This will depend on your background and skill level but generally whatever is easy to work with and accomplishes the goal. You can buy 3.3 volt relays that are 110v 10A rated, they work good with anything using 3.3v logic.
Arduino is a micro-controller (stupid but strong, power wise) RPI is a microprocessor (smart but weak, power wise). Short answer, Arduino can’t run an OS where the RPI can.
This question can have numerous answers, take some time and read theTutorials & Examples category to get some ideas. For a quick answer. You can buy something pre-made that works with Zigbee or Zwave and use one of the OH binding to control the device. If you prefer the more DIY route then look at the Sonoff switches or Esp8266/32 and use mqtt to communicate with OH.
i prefer to use as many wires as i can because i’ll rewire all the apartment and if i miss something i’ll use wireless. For sensors and switches i’d like to use CAT5 - 6 wire so spare wires will remain.
I don’t want to power the relays with Arduino or Pi, i want to power them with an external source (laptop) and use boards just to send the signal, that’s why i thought about 12/24 v relays, isn’t that possible without transistor and other electronics ?
In my example all the relay boards are 110-250V 10A rated but they are different types and shapes and technology (please check the links)
I know you cannot use OS on Arduino but you can combine both of them, right ?
Well, i don’t want pre-made expensive stuff each one with it’s own software, rules etc. I’d like to make everything as unitary as possible, not a “rainbow” of electronics
For my home I did something similar except I ran shielded two pair twisted wire for powering small devices like the Esp8266 and use wi-fi to communicate. If using cat6 maybe look at devices or ways to use POE.
If the relay requires 12/24v to energize then an external power supply will be needed along with a transistor so the 3.3/5v of Arduino/RPI can control the relay.
Yes they can be combined.
I’m the same way, for my setup I like to use Esp devices and flash either tasmota or Esp Easy firmware. I do have other smart devices that use Zigbee protocol, for those I use a CC2531 USB stick to communicate with OH.
I know this is an old/ish topic but I may be able to help.
I am moving from hass to openhab, and using esphome to control 16 (did try with 80 relays successfully, could have done more but ran out of relays) relays via esp8266 nodemcu. And as mqtt is supported with esphome it should be a very easy transition.
Happy to throw up some pics etc if you are still looking, as well as a howto.