Read values from arduino

I’ve to monitor the power produced by my solar panels.
I did some tries with arduino nano and ACS712 reading the analog pin and converting it to an interesting value.

Now I’ve to read it from raspberry and home assistant.
I would like to connect arduino and raspberry via wire (I2C ???), what do you suggest using?
Could you show me some examples? I’ve got to understand the wired connection and what I’ve got to configure in home assistant in order to read the value.


I am still new at Home Assistant but I have used I2C a fair amount.

Are you talking about using an Arduino to send information via I2C to a RPi running Home Assistant? ,If so they would need to be close to each other, say within 18" or so. I2C is very sensitive to distance.

Using I2C from the sensor to Arduino and then sending information via xbee / ZigBee, wifi, serial may work.

I would have to look into the components more to tell the best way. I doubt I helped but a few things to think about.

Unfortunately the distance will be about 10-15m :’(

Any other solution could be acceptable

A lot of possibilities.

I am looking at several, the one I like the best (so far) is to use a Raspberry Pi Zero W (or RPI 3) with the sensors sending MQTT information to HASSIO with Mosquitto MQTT add-on / MQTT sensor component to receive the data.

Do you have the power monitor / sensor? If so what type and what information does it provide?

AC voltage and current would be easy to monitor (after the inverter), DC voltage and current is doable but more difficult.

10 to 15 meters can be done with WiFi, Xbee or serial, there is an I2C range extender that may work that NCD makes (was Control Everything).

I apologize if this is getting off topic, hopefully not.

It looks like @Mariusthvdb may be doing something similar using a Rest API

ESP8266/ESP32 connected to your Arduino to provide network and MQTT capabilities…

1 Like

Thanks for all your suggestions.
@carbuthn I didn’t know anything about I2C range extender

As a power meter I’m going to use ACS712 that having analogic output I’ve got to connect it to Arduino

I did find information on building them (would not be to bad to do) also NCD makes them along with a lot of current sensors and power monitors (mostly they communicate I2C to a photon, RPi 3 / zero, ESP8266, electron / cell communications, Arduino’s etc). They have code samples for most programming languages.

I believe that MQTT will be the best for the distance that you are dealing with. If you don’t have WiFi or Ethernet available, you can use xbees to send it.