topic Re: Read LICELL Voltage in Software (Linux) from MMPF0200 in i.MX Processors

Read LICELL Voltage in Software (Linux) from MMPF0200

neuro — Thu, 06 Feb 2020 04:37:13 GMT

Hello,

I am currently running a system with an i.MX6 Solo X and a PF 200 power manager component. I am also running Linux.

I want to read the current voltage of the coin cell from the power manager device (LICELL pin).

I've been reading http://cache.freescale.com/files/analog/doc/data_sheet/MMPF0200.pdf?fasp=1&WT_TYPE=Data%20Sheets&WT_VENDOR=FREESCALE&WT_…

but no luck. I realize there is the i2c control for the coin cell however I don't want to set the voltage but only read the current voltage coming out of the battery via the power manager.

If there is a way to read on linux via sysfs that would be best. I know of the regulator devices in /sys/class/regulators but I'm not sure which one would be the for the external lithium ion battery (LICELL).

Thank you

Re: Read LICELL Voltage in Software (Linux) from MMPF0200

diegoadrian — Fri, 07 Feb 2020 18:55:07 GMT

Hello,

Unfortunately, that is impossible. You can only set an output voltage. Probably, that is because it needs to be done by a tensor divisor. This type of topology will drop out your output your voltage and it could drain your battery cell.

Best regards,

Diego.

Re: Read LICELL Voltage in Software (Linux) from MMPF0200

neuro — Mon, 17 Feb 2020 05:29:32 GMT

Thank you.

After reading your comment, this makes sense. If you want to read the battery you are draining it with that type of circuitry.