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Lets start with i'm a complete novice.

Pi Zero W: Used as a water level detector with the 3.3v and 3 GPIO pins soldered with some wires, that are spaced and attached to a pole, the 3.3v at the bottom and as the water increases/decreases it connects/disconnects the pins, which sends an alert with NotifymyDevice, runs on loop, as soon as the water level changes it sends an alert

Arduino Uno: Used as an Auto Feeder Has a 5v mini water pump, a moisture sensor, 5v relay, every hour the arduino checks the sensor and if the moisture level is low, turns on the pump for 1.5 seconds,

Wanted Outcome: When the feeder checks the moisture and if it has changed send a signal to the Pi which in turn sends a signal to NofitymyDevice, is it possible to connect the pi and arduino with a few connectors to get this done, if so could someone point me in the right direction, thanks

user1855290
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  • For Rpi newbies, I would suggest to first try Rpi "Serial/UART communication". You might like to see if to start with the following or similar tutorials: (1) https://www.teachmemicro.com/raspberry-pi-serial-uart-tutorial/, (2) https://raspberrypi.stackexchange.com/questions/96184/rpi3-to-arduino-serial-uart-communication-tutorial, (3) https://raspberrypi.stackexchange.com/questions/96697/how-many-serial-ports-are-on-the-pi-3. Have a nice Rpi project. Cheers. – tlfong01 Apr 24 '20 at 02:21
  • Try using some ESP8266, load mqtt publisher on it and add some sensors. ESP will send data to Raspberry and it may be processed further. This way you can always expand your system with much more nodes. – smajli Apr 24 '20 at 09:39

1 Answers1

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The nature of the signals you want to send are not clear.

I am going to assume you want to send a signal (without data) from the Arduino to the Pi.

The simplest way to achieve this end is as follows.

  1. connect the Arduino and Pi grounds (i.e. connect a wire between an Arduino ground pin and a Pi ground pin).
  2. Connect an Arduino GPIO to a Pi GPIO. This is not as straightforward as connecting a wire as the Arduino GPIO are 5V and the Pi GPIO are 3V3. One method is to use a couple of resistors as a voltage divider.
  3. To send a signal toggle the Arduino GPIO on then off for a brief period. This can be detected by software at the Pi end to trigger any needed processing.
joan
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