Analog pH circuit Reef-Pi

SoundsDigital · May 6, 2022

Currently building a reef-pi but unable to find the i2c pH circuit in stock anywhere in the UK. Is it possible to use the analogue variety successfully with reef-pi as I already have a couple of those unused?

Sral · May 6, 2022

If you have them lying around you could simply try. General consensus seems to be though, that you definitely need electrical isolation with the pH probes, which seems to be easier with digital circuits.

robsworld78 · May 6, 2022

SoundsDigital said:
Currently building a reef-pi but unable to find the i2c pH circuit in stock anywhere in the UK. Is it possible to use the analogue variety successfully with reef-pi as I already have a couple of those unused?

If the circuits put out an analog signal you'll also need one of these ADS1015 as the Pi doesn't have any analog pins to connect to. Reef-pi has a driver for these.

ADS1015 12-Bit ADC - 4 Channel with Programmable Gain Amplifier

For microcontrollers without an analog-to-digital converter or when you want a higher-precision ADC, the ADS1015 provides 12-bit precision at 3300 samples/second over I2C. The chip can be ...

www.adafruit.com

SoundsDigital · May 8, 2022

This would connect to the i2c like a temperature probe then and set up as a pH probe in the same manner as the probe?

Sorry for the silly questions, new to reef-pi and not very experienced with the Raspberry Pi either.

robsworld78 · May 8, 2022

SoundsDigital said:
This would connect to the i2c like a temperature probe then and set up as a pH probe in the same manner as the probe?

Sorry for the silly questions, new to reef-pi and not very experienced with the Raspberry Pi either.

The ADC would connect to the I2C pins, temperature doesn't use I2C, just a GPIO. Sorry I don't have any experience with an analog pH circuit and what you might expect, the driver in reef-pi may or may not work, I think it depends on the circuit.