ADC Conversion

[dhylands]

This appnote: http://processors.wiki.ti.com/index.php ... DC_Appnote suggests that Vref is 1.467V

This discussion also seems to agree: https://e2e.ti.com/support/wireless_con ... 8/t/401839

[danicampora]

Hi, it's probably an issue with the signal conditioning. What's the input impedance to the ADC pin? For instance, the expansion board has a capacitor on the battery monitoring circuit to maintain the value stable while the ADC is sampling.

[Oli_]

Thanks Dave for the very usefull reference.

Olivier

[Oli_]

Hi, it's probably an issue with the signal conditioning. What's the input impedance to the ADC pin? For instance, the expansion board has a capacitor on the battery monitoring circuit to maintain the value stable while the ADC is sampling.

Daniel,

Yes, the expansion board ADC input for the Lipo measurement is designed as recommended in the TI application note.
I'll do more deep measurement next week.

Olivier

[mbevilacqua]

Hi there!
Just got my wipy's today and still trying to get to grips with it. Running from a single cell lipo connected to the wipy expansion board. All jumpers are still in (specifically the one labeled BAT). Running the exact same code posted above but getting 4095 no matter what I do.

"MicroPython v1.6-89-g440d33a on 2016-02-27; WiPy with CC3200"

[mbevilacqua]

Ignore previous post... that was a 2S lipo, 7.4V, thought one cell was busted but it turns out it wasn't.
Hope I didn't screw the ADC input during those tests, we'll see!