I've got somewhat similar behavior to this timely thread, but I didn't want to clutter that thread up with my potentially different issue.
I've made my first custom Teensy-based board (versus daughter-boarding one on), using the MKL04 purchased from Paul and a blank MK20DX256VLH7. Schematic of the Teensy section should match Paul's for the T3.2, but I've included it here in case someone sees something I missed.
And the relevant board layout as well. The USB trace lengths match within a very small margin (I forget exactly, but we're talking a couple thousandths of an inch). The crystal was given it's own ground island connected to pin 31, with a via on the other side of said pin connecting to the main ground pours.
The behavior I see is the following:
Fresh power-up: Reset is low, with brief pops up to about 2.8V every ~50us (see screencap). Program is high at 3.28V.
When I short the program header (I don't have a button, but you can see the program and ground pins on the header near the MKL04 above), reset goes to 0V until I release the button, then goes high to 3.225V for a while (~110ms on the trace below), then goes low, pulses again at the 50us interval for a few cycles (15 in the trace shown), then stays low for a while (seems to vary, but several hundred ms), before returning to high and staying there until I power cycle the whole shebang.
At no time does Windows (Win10) ever show any sign of seeing the device (no ding-dong, no pop up, never appears in device manager that I can find, attempting to program via the Arduino IDE does not ever see the board, etc).
I don't have access to a proper oscilloscope, just this Saleae Logic 8 logic analyser, which seems to have no luck probing the crystal (I'm guessing too much capacitance?). The crystal I used was a TSX-3225.
Any thoughts?
I've made my first custom Teensy-based board (versus daughter-boarding one on), using the MKL04 purchased from Paul and a blank MK20DX256VLH7. Schematic of the Teensy section should match Paul's for the T3.2, but I've included it here in case someone sees something I missed.
And the relevant board layout as well. The USB trace lengths match within a very small margin (I forget exactly, but we're talking a couple thousandths of an inch). The crystal was given it's own ground island connected to pin 31, with a via on the other side of said pin connecting to the main ground pours.
The behavior I see is the following:
Fresh power-up: Reset is low, with brief pops up to about 2.8V every ~50us (see screencap). Program is high at 3.28V.
When I short the program header (I don't have a button, but you can see the program and ground pins on the header near the MKL04 above), reset goes to 0V until I release the button, then goes high to 3.225V for a while (~110ms on the trace below), then goes low, pulses again at the 50us interval for a few cycles (15 in the trace shown), then stays low for a while (seems to vary, but several hundred ms), before returning to high and staying there until I power cycle the whole shebang.
At no time does Windows (Win10) ever show any sign of seeing the device (no ding-dong, no pop up, never appears in device manager that I can find, attempting to program via the Arduino IDE does not ever see the board, etc).
I don't have access to a proper oscilloscope, just this Saleae Logic 8 logic analyser, which seems to have no luck probing the crystal (I'm guessing too much capacitance?). The crystal I used was a TSX-3225.
Any thoughts?
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