Thank You

@RichardBH The Pycom development modules are supplied by the Vin Pin. The 3.3V Pin of the modules is the output of the internal regulator. AFAIK, this is an LM3281 device with an absolute maximum input voltage of 6V. Between the Battery plug and the Vin pin is the charge chip and some switching circuitry. They should not cause a major voltage drop. So: If you are absolutely sure that the battery voltage is never above 6V, you could connect it. But typically, the voltage of a fully charged/fresh battery is above its nominal voltage. Like: 6V Lead battery, full charged 7.2V, 1.5 V Alkaline: fresh ~1.6V, ... So you will need some means to limit or lower the input voltage.

@jc_serg That looks bad then. Since 3.3V is an output of the board, it means that the board is not working. Are you sure you plugged in the board in the right orientation?

@catalin Thank you. :o)

@MJ1 If it shows up as COM port, then you can use it for your Pycom device.

You can check if the board is affected by sending the S/N to Pycom support (see the link to Expansion Board 3.1 issues). I have 2 boards with DFU lock in, but Pycom support already sent the replacements. You don't get a serial connection via USB with these boards, but besides that still are functional. Pymakr connection via WLAN and FTP are working (Lopy4 powered up and running). AFAIK - and proved by buying another board some weeks ago - if you now buy an EXP 3.1 you will not run into that problem. If your board is older, just check with support before trying to update it.

Same topic: https://forum.pycom.io/topic/2469/easy-way-to-tell-what-expansion-board-is-in-use Here's a method to create a generic exp. board object: from pycoproc import Pycoproc from pysense import Pysense from pytrack import Pytrack # create exp board object using unknown board type pyexp = Pycoproc(1) if pyexp.read_product_id() == 61458: print("Using Pysense") pyexp = Pysense() if pyexp.read_product_id() == 61459: print("Using Pytrack") pyexp = Pytrack() Later on use eg: if pyexp.board_type == pyexp.PYSENSE: si7006 = SI7006A20() Perhaps someone can tell us the id for the Pyscan board.

Thank You

@stanschultz Also very useful: https://github.com/zsquareplusc/mpy-repl-tool

@GreenGrouch Try to move the line "p_inP14 = Pin ..." before the while instruction

@aventri My guess is that you haven't installed the drivers to allow you PC to see the Expansion Board com port? When I was starting with GPY, I found this tutorial from Core Electronics in Australia, to be very helpful.. https://core-electronics.com.au/tutorials/pycom-gpy-getting-started.html It is Windows centric, but there are others to be found as well

@weingami Note that I2C level shifting is particularly easy as it uses an open drain-pullup signaling scheme. Shifting can simply be done with two FETs: https://electronics.stackexchange.com/questions/255607/i2c-level-shifting-mosfet

This is an old topic but would like to add some comments that can be useful to someone having this kind of issues. I have an expansion board 3 with a Wipy, using the SD card and some sensors, and everything is working well being powered throu USB or battery. I had some issues that were fixed by following these steps: When powered by battery, P19 and P20 are affected by RTS and CTS respectively, and it was blocking one sensor I have connected to those pins. Removing those jumpers from Expansion Board resolved this issue. Don't use P8 with any sensor if you are using SD card. Looking at the Wipy3 pinout, I suppose the same is true for P3, P9 and P10. Even thou, P10 is also connected to the user button, then I configured it as an input pin with pull=PULL-UP, and avoid read/write SD operations and user button clicks at the same time. Also, this post helped me with a weird behavior of user button when using the battery: https://forum.pycom.io/topic/7364/exp-board-user-push-button/3?_=1648562954689 I connected the 10K pull-up resistor to P8 as indicated in the expansion board documentation, but honestly, I don't understand why it's needed. Most of these "tricks" are not clearly documented and I found them reading several posts and connecting ideas between them. In my opinion, Pycom boards are very good in general (with a very few details that could be improved), but as said in many places, its documentation should be reviewed to add many things like these that one has to chase reading somewhere else or by try/fail methods.

@alvaroav Hey glad its working. I've raised it in the team so hopefully the fixes will get ported into the next pybytes firmware release.