mikemontauk
Active member
Hello, I built a board with a MKL02 chip with pre-programmed Teensy and MKL26Z64VFT4 (Teensy LC). Last night I ran a blink program successfully. I connected program (MKL02 PTB2 [QFN Pin 10]) to ground according to the troubleshooting forum and all was good. Next, I uploaded a MIDI USB test program (without needing to pull program to ground) and was successfully able to read MIDI over USB and blink an LED for each note-on message received. Then, I uploaded a MIDI serial test program (attached) and it worked correctly. (At this point I was ecstatic)
However, I have lost the ability to upload new code. Pulling program to ground does not appear to do anything. The MIDI serial program is running when the teensy is powered on and the serial monitor displays the MIDI serial notes in real-time so the teensy is connected to Arduino and the USB connection appears to be working.
I purchased another bootloader chip just to rule that out, but I suspect it was not damaged. Is there anything I can check with my scope regarding the upload sequence? Also, I am providing 5V separately from the USB (which btw is a USB-C), so power and USB data to the chip are not connected and disconnected simultaneously; could that create an issue?
The only variable that changed was the actual code running. Could the MIDI serial test program (attached) be preventing programming?
Disclaimer - serial midi input test code attached is not mine its from https://www.pjrc.com/teensy/td_libs_MIDI.html
However, I have lost the ability to upload new code. Pulling program to ground does not appear to do anything. The MIDI serial program is running when the teensy is powered on and the serial monitor displays the MIDI serial notes in real-time so the teensy is connected to Arduino and the USB connection appears to be working.
I purchased another bootloader chip just to rule that out, but I suspect it was not damaged. Is there anything I can check with my scope regarding the upload sequence? Also, I am providing 5V separately from the USB (which btw is a USB-C), so power and USB data to the chip are not connected and disconnected simultaneously; could that create an issue?
The only variable that changed was the actual code running. Could the MIDI serial test program (attached) be preventing programming?
Disclaimer - serial midi input test code attached is not mine its from https://www.pjrc.com/teensy/td_libs_MIDI.html