i.MX ProcessorsのトピックRe: SNVS Coin cell voltage read

SNVS Coin cell voltage read

kevi49 — Tue, 15 Nov 2022 12:02:17 GMT

Hi NXP Team,

We are using the iMX6sX processor which have SNVS functionality enabled and everything is up and running,

But we have one requirement to read the coin cell voltage if it is low,

Is there any registers or method available to read the voltage or generate trigger so user may aware about to change the coin cell battery.

Thanks

Re: SNVS Coin cell voltage read

Harvey021 — Mon, 21 Nov 2022 07:31:00 GMT

Hi @kevi49

As far as I know that you can use a voltmeter to measure.

Best regards

Harvey

Re: SNVS Coin cell voltage read

edwardtyrrell — Mon, 21 Nov 2022 10:47:01 GMT

Hi @kevi49

You could use an ADC input and put together a small program or script that polls the ADC line. After a bit of conversion to get what the ADC is reading in volts or millivolts then you can set a trigger point to alert the user etc. Depending what you hardware is i.e if you're on a dev board you may have some preconfigured ADC inputs, if not see if you can find a suitable spare pin on your board. Do the normal device tree, and kernel configs and then a simple 'cat /sys/bus/iio/devices/iio:device0/in_voltage1_raw' (or similar) will show it's working. Connect it to your battery line somehow with suitable resistive dividers etc and you might be in business!

Hope it helps.