Hardware Debugging

• Connection issues

  1. Ensure you performed the checks in Unpacking & Hardware Overview

  2. If your computer doesn't see the PyCubed board as a mass storage device
     (but the RGB is cycling through a rainbow of colors
     as described)
     • Confirm the USB port on your computer isn't a "power only" port by plugging another USB device (like a flash drive) into that port.

  3. If your computer doesn't recognize PyCubed and there is no rainbow LED as described.
     • It's likely the board isn't getting power.
       • Confirm the USB port is working on your computer by plugging another USB device into that port.
     • Visually inspect the board for any foreign debris that may be causing a short-circuit on the board.

• My board isn't generating 3.3V

  • Did you build the board yourself? Check that the USB port properly soldered on and plugged into a known-working USB port on your computer.

  • Are the mechanical inhibits shorted as described here?

  • Inspect the board for any debris that may be causing an unwanted electrical short.
    • A short between 3.3V and ground will trigger the primary 3.3V regulator's short-circuit protection (thereby disabling the 3.3V rail).

• The green "CHRG" LED blinks when I plug my board into my computer

  This is because the PyCubed hardware hasn't been initialized since powering the board via USB

  • Opening the REPL and sending from pycubed import cubesat should make the blinking stop.

  • Usually this is handled by main.py since from pycubed import cubesat is typically one of the first things we do.

  The blinking is the USB charger saying it doesn't see a battery attached.

• My board restarts when I try to transmit using the radio

  This indicates the radio is starved for power which results in the 3V3 rail dropping.

  Solutions:

  1. If you're powering the board via the USB cable and just trying to transmit for testing purposes:
     • Make sure the RF regulator is disabled.
       • 📄 Because of the global chip shortage of 2021, the RF regulator can be either U7 or U21. Instructions on disabling the RF regulator in software:

         • If your board has U7 populated, your regulator should be disabled by default, but double check by confirming /lib/pycubed.py line 107 says the following:

           self.enable_rf.switch_to_output(value=True)

         • OR if your board has U21 populated, your regulator is enabled by default. Disable it by changing /lib/pycubed.py line 107 to say the following:

           self.enable_rf.switch_to_output(value=False)

  2. If you're attempting to transmit using maximum output power (max_output=True):
     • Ensure you have a 2S li-ion battery (7.2-8.4V) attached.
     • If you're testing on the bench, ensure that your High Side and Low Side inhibit connectors are bypassed. See 🔓Inhibits & RBF Header for more details
       (you'll want the "Benchtop Testing - With Battery" configuration)
       
     • Confirm that you have an antenna securely attached to the "Radio #1" connector. See 📡Antennas for more details.
     • Ensure your RF regulator is enabled:
       • 📄 Because of the global chip shortage of 2021, the RF regulator can be either U7 or U21. Instructions on enabling the RF regulator in software:

         • If your board has U7 populated, your regulator should be disabled by default, enable it by changing /lib/pycubed.py line 107 to say the following:

           self.enable_rf.switch_to_output(value=False)

         • If your board has U21 populated, your regulator should be enabled by default, but double check by confirming /lib/pycubed.py line 107 says the following:

           self.enable_rf.switch_to_output(value=True)

  High Power Radio Output

• My RGB LED (neopixel) is acting weird

  We've noticed lot-variability of RGB LEDs (P/N WS2812-B) from the manufacturer (Worldsemi). Particularly, we've seen some (but not all!) LEDs start acting strange after applying a strong normal force to the top of the LED, possibly causing damage to internal wirebonds (specifically the bond interface).

  • One fix is to apply a SMALL amount of heat to the LED package (either via a hot air hand piece or touching a soldering iron to each lead). Iterate between applying small amounts of heat and then testing the LED. This fixed about 90% of the LEDs we tried.

  • We will switch manufacturers once our supply of RGB LEDs is depleted (or we encounter more of these misbehaving LEDs).

Software

• General software development

  1. Make sure to work through all of the quick start pages: ⚡Hands-On Quick Start

  2. Visit 🖥️Code Examples

  3. Visit Example Flight Software

  💡

  Remember
  Coding and using PyCubed is exactly like using other CircuitPython boards. Learn, troubleshoot, and get inspired by seeking out
  CircuitPython projects on the web.

• Trouble with Mu

  1. If you get a Mu-specific error, ensure you followed the instructions in Download Mu.

  2. Restart your computer after installing Mu.

  3. Board not recognized?

     Prior to Mu 1.1.0-beta-4 release, Mu Editor did not recognize PyCubed as a CircuitPython device. If you encounter this, try reinstalling Mu.

     • Still not recognized?

       try an earlier release for Mu: https://github.com/mu-editor/mu/releases

     • How to manually add valid board types to Mu
       (no longer necessary)
       

       On Mac

       1. Close Mu (if it's open) and navigate to the Mu installation directory (might look something like this: /Applications/mu-editor.app/Contents/Resources/app/mu/modes)

       2. Open the /adafruit.py file in a text editor and add (0x04D8, None), to the the valid_boards list (somewhere around line 54) and save. The file should now contain something like:

          ...
            (0x1B4F, 0x8D22),  # SparkFun SAMD21 Mini Breakout
            (0x1B4F, 0x8D23),  # SparkFun SAMD21 Dev Breakout
            (0x04D8, None),    # PyCubed related boards
          ]

       On PC

       1. Follow the same steps as for the mac, except the adafruit.py (it might also be called circuitpython.py) file will be located in a directory similar to...
          
          C:\Users\USERNAME\AppData\Local\Mu\pkgs\mu\modes

          (make sure to change 'USERNAME').

       • Can't find the circuitpython.py file?

         If you're on PC, try looking for the install location: MU-INSTALL-PATH\pkgs\mu\modes

🖱Accessing the Serial Console

Firmware

• Atmel Studio 7 is unable to communicate to the microcontroller via SWD (JTAG)

  • Make sure the enable resistor for the external watch dog timer (WDT) is not soldered on to the board (R42).

  • Check the voltage on 3V3. See this troubleshooting section if it does not read 3.3V +/- 0.2V.

Still having trouble?

1. Check the 💬 PyCubed Forums

2. Check the❔FAQ

3. 📧Contact Us