PocketBeagle interface to LiPo cell

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#1

Hi all,

So I've researched this a bit, and the answers I've come up with so far
are vague. I'm looking to build small packet radio terminals around the
PocketBeagle single-board computers to interface RFID readers being used
in horse endurance ride events.

Now, I've read up on the OSD3588 and its embedded TPS65217C.

I'm looking to use these cells to power the devices:
https://core-electronics.com.au/polymer-lithium-ion-battery-18650-cell-2600mah-solder-tab.html

All that's inside the box in addition to this is a MAX3232 level shifter
hooked up to UART2/UART4 (the one chip does TX/RX of both UARTs). The
aim is to allow the real-time clock in the PocketBeagle to retain time
and act as a UPS for the duration of a week-end long event.

From what I've been able to piece together, ideally a thermister is
required, and one of the schematics in the TPS65217C datasheet calls out
a 10kohm one specifically, along with a parallel 75k resistor.

I'm thinking this will be soldered to the negative end tag of the cell
and heat-shrunk to the cell body with the output wire from the
thermister joining wires from the two ends of the cell.

This is the thermister I'm looking at getting:
https://core-electronics.com.au/thermistor-10k.html

Would this suffice, or are there specific requirements I should be
looking for?

Also, I hear somewhere that the TPS65217C needs to be configured to
enable charging of the LiPo cell: is that already done by the standard
BeagleBone/PocketBeagle image or should I be looking at the data sheet
for the appropriate I²C commands?

Regards,

#2

Hello!

This has been my back-burner project since I started looking at Pocket Beagle. I'll get back to it soon. I got a thermistor a while ago and will get a test bed set up again, finally, again.

It's my understanding the thermistor is required for charging and you can just use a 10k resistor for simple discharge use.

I need to verify this and check on the firmware side of things. Back when I started with Pocket Beagle, fw update was needed to support charging.

Regards,
Fred

#3

Hello!

This has been my back-burner project since I started looking at Pocket Beagle. I’ll get back to it soon. I got a thermistor a while ago and will get a test bed set up again, finally, again.

It’s my understanding the thermistor is required for charging and you can just use a 10k resistor for simple discharge use.

The thermistor isn’t required, just a safety measure. Care around LiPo batteries should always be considered.

I need to verify this and check on the firmware side of things. Back when I started with Pocket Beagle, fw update was needed to support charging.

I’ve been doing charging with the latest images that seem to have it enabled. I’ll try to put a GamePup on a scope the next few days to see that it is doing, but the battery gets charged.

#4

What is a GamePup? :slight_smile:

#5

What is a GamePup? :slight_smile:

https://beagleboard.org/gamepup