Source code

+5V → ODROID C1/4

GND → ODROID C1/6

Jumper SLAVE OUT. Jumper MASTER OUT. Hub I2C GND and VDD to ADC GND and VDD.

ODROID C1/3 → I2CHOB02B/SDA

ODROID C1/5 → I2CHOB02B/SCL

I2CHOB02B/1/SDA → I2CADC01A/SDA

I2CHOB02B/1/SCL → I2CADC01A/SCL

Power +5V to I2CADC01A and OZDUAL02B.

Jumper REF- GND.

I2CADC01A/Vref → OZDUAL02B/-in

I2CADC01A/REF+ → OZDUAL02B/Vref

I2CADC01A/IN+ → OZDUAL02B/out

I2CADC01A/IN- → OZDUAL02B/-in

OZDUAL02B/Vref → pH probe -

OZDUAL02B/+in → pH probe +

schematic of ADC