Battery adapter for E-Series

Hello community,

We used our E-Series electronic with two other modules, each requiring 3v power. We have tried to power the two modules using a 3.7v 1800MAh battery but unsuccessful. Any idea or guidance on how to get this two items to successfully run on battery?


Hi there,

What are the modules you are referring to? Generally this should be possible, but you would probably require a regulator to drop the voltage down to 3V3.

Hello @no1089,

The two modules are a timing controller and a 11.3" eink display. The timing controller is connected to the particle board and the display is connected to the timing controller. Previously, we could only get the display to update information on the screen if the particle board is connect to dc power. Powering the board with only the 3.7v battery could not supply the display with enough voltage to function properly. Just earlier today, we successfully made some twerking to finally achieved only battery operation. One of the thing we did was swap the timing controller cable that was connected to the Vin pin and move it to the Lipo pin. We performed some testing and it seems to be working now. Do you think we still need to add a regulator?

If you are able to power the display from Li+ you should be fine. The E Series module has 5V tolerant GPIO so even if the timing controller is sending data to the E Series MCU everything is fine.

Note: This is not the case with Gen 3 devices (Boron, B Series SoM, Tracker SoM) so some level shifting may be necessary for these devices, as they only support 3.3V logic levels.

Hello @rickkas7,

Thanks for the info. We are actually using the E-Series temporarily until our tracker SoM arrived. We will transfer everything we are currently doing with the E-Series over to the tracker SoM. What do you suggest we do to achieve a batter-only operation with the tracker SoM?

It depends on how the timing controller communicates with the MCU. If the timing controller is powered by Li+ it has the possibility of being 3.6V to 4.2V, which has logic levels higher than the nRF52 in the Tracker SoM can handle.

If the timing controller is a receive-only device, you’re fine. If it’s an I2C device that can operate at 3.3V I2C you’re also fine.

However, if it uses SPI you need to level translate MISO as the signal from the timing controller will be at too high of a voltage for the Tracker SoM (or any Gen 3 device).

Likewise, serial to MCU would be an issue. Any interrupt pins that are push-pull (not open collector) would also need to be level-shifted.

I can’t say that the timing controller is a receive-only device. I will need to ask my team member who is more technical to confirmed. What I do know is that the TCON receives updates from the particle board and pushes that info to the eink display which is then projected on the screen. The connection between the TCON and the particle board is through UART and SPI is used for the connection from the TCON to the eink display. Yes, I2C is on the TCON.