Electric Potato
Well-known member
Hey guys,
I'm troubleshooting a custom T3.5 that uses the 100-pin LQFP variant of the MCU (MK64FX512VLQ12) instead of the 144 MAPBGA.
Everything looks good but my computer won't respond to the board.
My only lead I have is that the bootloader pins connected to Reset_B on the MCU are always reading .08V, which I'm pretty sure is incorrect because on the working custom T3.2's I have, those pins always read 3.3V.
I've checked all my connections pretty extensively, verified 5V/3.3V/GND/USB are connected correctly, and also removed the bootloader and stuck it into a working T3.2 custom board, and that board worked fine so I know I didn't fry the bootloader or something like that.
I attached my schematic in case anybody could do me the huge favor of taking a quick look; it's mostly the same as Pauls T3.5
just without the pins that don't exist on the 100pin package. I also left off the dual schottky and added a voltage divider
into A10 for monitoring battery voltage but I think that's it.
The layout I used for the board is very similar to what I used in my T3.2 builds, which all have worked fine, and touchier things like crystal layout are identical to what I used for those boards.
Anyway thanks for any ideas!
I'm troubleshooting a custom T3.5 that uses the 100-pin LQFP variant of the MCU (MK64FX512VLQ12) instead of the 144 MAPBGA.
Everything looks good but my computer won't respond to the board.
My only lead I have is that the bootloader pins connected to Reset_B on the MCU are always reading .08V, which I'm pretty sure is incorrect because on the working custom T3.2's I have, those pins always read 3.3V.
I've checked all my connections pretty extensively, verified 5V/3.3V/GND/USB are connected correctly, and also removed the bootloader and stuck it into a working T3.2 custom board, and that board worked fine so I know I didn't fry the bootloader or something like that.
I attached my schematic in case anybody could do me the huge favor of taking a quick look; it's mostly the same as Pauls T3.5
just without the pins that don't exist on the 100pin package. I also left off the dual schottky and added a voltage divider
into A10 for monitoring battery voltage but I think that's it.
The layout I used for the board is very similar to what I used in my T3.2 builds, which all have worked fine, and touchier things like crystal layout are identical to what I used for those boards.
Anyway thanks for any ideas!