No CIRCUITPY after installing circuitpython on PyPortal

[zizumara]

I have a PyPortal board and I am attempting to program it via USB on a Windows 10 laptop. I used to see the CIRCUITPY folder on previous installations of CircuitPython, but that no longer appears. I can still get the PORTALBOOT folder to show up when pressing the reset button twice. I also disabled AutoProtect and Smart Firewall on Norton, since another user posted that as an issue somewhere.

Here's the sequence:
Press reset twice. PORTALBOOT window opens on Windows 10 desktop. INFO_UF2.TXT reads
UF2 Bootloader v3.13.0 SFHWRO
Model: PyPortal M4 Express
Board-ID: SAMD51J20A-PyPortal-v0
Drag and drop adafruit-circuitpython-pyportal-en_US-7.0.0.uf2 to PORTAL boot folder. Folder closes and all LEDs on PyPortal turn off.
Wait a couple of minutes. Nothing changes. PyPortal display is blank.
Press reset on PyPortal once. After a few seconds, status LED turns yellow and green. Display is blank. No change on Windows desktop.
Press reset twice. Yellow LED turns off and PORTALBOOT window opens. INFO_UF2.TXT reads the same as before.

I tried the same thing above with PYPORTAL_QSPI_Eraser.UF2 and got the same results. INFO_UF2.TXT remains the same.

[tannewt]

Does version 6.3.0 from here work: https://adafruit-circuit-python.s3.amaz ... tal/en_US/ ?

Have you installed any drivers when trying to fix this? It shouldn't need drivers and they could be messing things up.

[zizumara]

Actually, I did try version 6.3.0 of CircuitPython earlier, and the results were the same. But I have some new symptoms to report.

I have been following the instructions from https://learn.adafruit.com/ez-make-oven to build a DIY solder reflow oven. During all of the testing so far, I have had the MCP9600 thermocouple amplifier attached to the PyPortal. I just discovered that if I disconnect the MCP9600 from the PyPortal, CircuitPython runs the oven program prints status to the display until it fails to find the MCP9600 and exits the program with an exception. Removing the MCP9600 also allows the CIRCUITPY folder to open in Windows.

I carefully inspected the connections and solder joints on the MCP9600. All of connections are exactly as documented by Adafruit, and the pin header solder joints are good without any solder bridges. I even tested the resistance between the MCP9600 VIN and GND pins and determined the resistance is several mega Ohms. I have a lot of experience soldering pin headers to boards -- I used a small soldering tip and set my solder station to 700 F and use a little solder flux on each pin, so I am pretty sure that I did not overheat the board during soldering.

Note that I have NOT altered the I2C port supply voltage jumper on the PyPortal board, so it should still be supplying 3.3V to the amplifier board. Could this be a defective MCP9600 board?

[zizumara]

P. S. : I did not install any new drivers.

[zizumara]

New progress to report. I went ahead and cut the 5V jumper on the PyPortal and added a solder bridge to the 3.3V pad. Now the code runs with the thermocouple amplifier connected. So supplying 5V to the amplifier appears to have been somehow locking up the PyPortal. But the calibration.py code now fails as follows.

Traceback (most recent call last):
File "code.py", line 549, in <module>
File "adafruit_display_text/bitmap_label.py", line 87, in __init__
File "adafruit_display_text/__init__.py", line 240, in __init__
File "adafruit_display_text/__init__.py", line 261, in _get_ascent_descent
File "adafruit_bitmap_font/bdf.py", line 75, in ascent
OSError: [Errno 22] Invalid argument

This is with CircuitPython 7.0.0. If I load CircuitPython 6.3.0, I get an "incompatible mpy file" on line 12 of code.py.

[zizumara]

OK, I think I have finally resolved my issues. To fix the latest problem, I removed all files from CIRCUITPY and carefully copied from the Easy Make bundle ONLY the files listed in the instructions. Now the Easy Make Oven Controller display comes up as expected.

I'm not sure I would tag this project as a "beginner" project unless the instructions are more explicit. For one, I recommend stating exactly which files go into which folders. For another, I would like to suggest that your note on changing the I2C supply voltage be fleshed out to state exactly which symptoms are an indication that the 3.3V jumper is needed. And why is there any uncertainty about whether Adafruit's MCP9600 sensor board requires 3.3V in this project?

[danhalbert]

MCP9600 chips with date codes 1845 or before had a flaw in their I2C implementation. If you have an old one you may have the bad chip. See the Technical Details section on the product page: https://www.adafruit.com/product/4101

[zizumara]

In the technical details section, Adafruit states that it would not ship versions of the MCP9600 board exhibiting this problem after October 2018. I purchased my MCP9600 board this year from Adafruit.

Using the 3.3V output from the PyPortal is an acceptable solution to the problem, so I consider this issue closed.