Hello Andrew again,
Today, I tried to measure the voltage using your demo read_voltage.
DC battery voltage 1.5 was applied to every 8 x inputs one by one.
Actual battery voltage was 1.615V connecting the voltage meter always.
demo read_voltage program has not made any changes as it is.
input 1: 1.611, input2: 1.620, input3: 1.611, input4: 1.618, input5: 1.613
input6: 1.611, input7: 1.613, input8: 1.613
* numbers were DC voltage showing at console
It looks very good.
Then, tried to change adc = ADCPi(0x68, 0x69, 12) to 18 bit in demo program
input 1: 1.6105, input2: 1.621, input3: 1.612, input4: 1.618, input5: 1.629
input6: 1.611, input7: 1.613, input8: 1.612
Almost same as 12 bit. I do not know why only small changes. Is it OK such data ?
Further, the DC battery voltage has increased to 3.231V and I tried to measure the DC voltage.
However, when run the demo program, every inputs showed " 0.0000" at console.
I again checked the battery voltage during measurement, it is sure to apply the 3.231V always. Then, the battery voltage was changed to 1.615V and run the demo program, Console showed same voltage at every inputs as before.
I think max. input voltage of ADC Pi Plus is 5VDC, how can I measure max. 5VDC ?
Could you kindly help me with this.