Teensy 4.0 - Unable to program when VIN cut
I'm moving a T3.6 project to T4 and am running into a strange issue. It's affected two T4 boards so far.
Both boards respond normally and program successfully when plugged into a computer before the VIN trace is cut. However, once the trace is cut, I can no longer program the boards. They both power up fine and enter into program mode when the on-board button is pressed but they will not appear as a device on any of my computers.
The bizarre issue is, if I solder the VIN pads closed, the boards appears on my computer as expected (but without the ability to power the board externally while connected to a computer).
I'm using an MCP1826S 1A 3V3 LDO connected to the VUSB pin on the Teensy, so power and data require only one cable.
The on-board regulator is too small for my project.
Does anyone have any suggestions?
I'm moving a T3.6 project to T4 and am running into a strange issue. It's affected two T4 boards so far.
Both boards respond normally and program successfully when plugged into a computer before the VIN trace is cut. However, once the trace is cut, I can no longer program the boards. They both power up fine and enter into program mode when the on-board button is pressed but they will not appear as a device on any of my computers.
The bizarre issue is, if I solder the VIN pads closed, the boards appears on my computer as expected (but without the ability to power the board externally while connected to a computer).
I'm using an MCP1826S 1A 3V3 LDO connected to the VUSB pin on the Teensy, so power and data require only one cable.
The on-board regulator is too small for my project.
Does anyone have any suggestions?
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