dirkenstein
Active member
I've just bricked a teensy 4.0 which won't show up in USB anymore. It goes into program mode OK when if you press the program button (red light comes on) but teensy loader never sees it (1.53 Mac 10.14).
I've tried pressing the program button before plugging in the USB but that doesn't help.
The last program I tried to upload had very small amounts of stack space left over(< 3K) as static variables take up most of the memory. When uploaded, the program didn't work.
I'm wondering if a program with too little stack space can brick a teensy. Does the program mode assume the stack pointers are valid from the running app? I'm thinking the USB interrupt code runs out of stack space and program mode doesn't force the stack pointers back to sensible defaults- does it assume the stack space from the program is valid?
I may of course have damaged the USB interface in some way (the board is powered from a 9V supply regulated to 5V, and i forgot to chop the vin/vusb link).
However, it's a very weird coincidence that it stopped working just as i tried to program a 'Stability problems may occur' image onto it.
I'm reluctant to try another teensy in case i've discovered a way of reliably bricking it.
Suggestions?
I've tried pressing the program button before plugging in the USB but that doesn't help.
The last program I tried to upload had very small amounts of stack space left over(< 3K) as static variables take up most of the memory. When uploaded, the program didn't work.
I'm wondering if a program with too little stack space can brick a teensy. Does the program mode assume the stack pointers are valid from the running app? I'm thinking the USB interrupt code runs out of stack space and program mode doesn't force the stack pointers back to sensible defaults- does it assume the stack space from the program is valid?
I may of course have damaged the USB interface in some way (the board is powered from a 9V supply regulated to 5V, and i forgot to chop the vin/vusb link).
However, it's a very weird coincidence that it stopped working just as i tried to program a 'Stability problems may occur' image onto it.
I'm reluctant to try another teensy in case i've discovered a way of reliably bricking it.
Suggestions?