Always reading same battery voltage

[mmarkvoort]

@bucknall

Sorry, can only post every 600s.

I am using pymakr (I know it isn't a good idea). What other options do I have to check?

But even when writing the value to a text file, without the usb, it is giving me the same value.

[bucknall]

Hi @mmarkvoort,

Are you trying to measure the voltage while you have the board powered over USB, i.e. using the REPL to check?

[mmarkvoort]

@livius

When using the code that was given in the forum post (which uses attenuator 1) + changing to what you said (so changing it to 3).
I get this:
Mean of ADC readings (0-1023) = 1509.5199584960937
Mean of ADC readings (0-1400 mV) = 2063.7967586517333
Variance of ADC readings = 27.4036669731140
10* * 6 * Variance/(Mean**2) of ADC readings = 12.0000004768372

When I use the adc from docs.
I get:
1520 and the next read 1530.

It does change something, but still doesn't look good to me.

Does the USB cable matter?

[livius]

@mmarkvoort

try use attenuator (i do not know why it is not documented)

apin=adc.channel(pin='P13', attn=3)

do you use it like in post you link?