potatotron
Well-known member
I just received my teensy 3.0, it's fantastic. I'm really impressed by the completeness and features; it's going to make at least one of my projects an order of magnitude simpler.
Because I can't stand not knowing things, I'm trying to wrap my head around how it actually works. I've been digging through the schematics and data sheets and from what I can tell teensyduino has a basic initialization wrapper for the ARM stuff in mk20dx128.c but there's no hooks for reprogramming etc. in the Arduino-fied MK20 code itself?
From what I can tell when you press the 'program' button the mini54 resets the MK20 and looks like it's doing something with JTAG? ...uploading code to erase the flash, read data from USB and write that to flash, then reboot the MK20? If so, what doe the pins on PTB2 and PTB3 do? Are you sending something between the chips via I2C? Also, why does PTA3 need two mini54 pins (P0.5 and P0.6)?
I apologize if this is already documented somewhere else, or if you consider this proprietary information and don't want to reveal it publicly.
Thanks again for a great product, I think I'm going to have to order boards #2 and 3 in a few days because this first one is already working out better than I'd hoped.
Because I can't stand not knowing things, I'm trying to wrap my head around how it actually works. I've been digging through the schematics and data sheets and from what I can tell teensyduino has a basic initialization wrapper for the ARM stuff in mk20dx128.c but there's no hooks for reprogramming etc. in the Arduino-fied MK20 code itself?
From what I can tell when you press the 'program' button the mini54 resets the MK20 and looks like it's doing something with JTAG? ...uploading code to erase the flash, read data from USB and write that to flash, then reboot the MK20? If so, what doe the pins on PTB2 and PTB3 do? Are you sending something between the chips via I2C? Also, why does PTA3 need two mini54 pins (P0.5 and P0.6)?
I apologize if this is already documented somewhere else, or if you consider this proprietary information and don't want to reveal it publicly.
Thanks again for a great product, I think I'm going to have to order boards #2 and 3 in a few days because this first one is already working out better than I'd hoped.