Last but not least, those boards need programming. I found some documentation from NXP that suggests that Kinetis devices have a factory-installed USB-capable boot loader in their Flash [1], but that doesn't seem to apply to the KL26 chips I have. Maybe this was only added after Freescale became part of NXP.
[1] http://www.nxp.com/assets/documents/data/en/user-guides/KFLLDRUG.pdf So we still have to use good old SWD (Serial Wire Debug). In the past, I soldered wires directly to the test pads, but it would be much nicer to have a proper programming and testing fixture. I started to design a modular and general fixture, but that got unpleasantly complex. Also, once the test points and their locations have settled, all that flexibility won't be needed. I especially didn't want to have to make a lot of PCBs for this. Then it occurred to me that I could probably do it without PCB: a 3D-printed base can hold the pogo pins at the right locations, and the remaining wiring is simple enough that no PCB is needed. This is what the result looks like, top and bottom: http://downloads.qi-hardware.com/people/werner/anelok/tmp/mk3-partial/quick-fix-top.jpg http://downloads.qi-hardware.com/people/werner/anelok/tmp/mk3-partial/quick-fix-bottom.jpg I made the holes large enough that the pogo pins would go in most of the way. Then I heated them with the soldering iron set to 190 C (PLA gets soft around 180 C) and gently pushed them into the plastic until they were fully inserted. Soldering the wires didn't heat up the pogo pins enough to melt the PLA. With a PCB inserted, it looks like this: http://downloads.qi-hardware.com/people/werner/anelok/tmp/mk3-partial/quick-fix-pcb.jpg And here we have the Ben NanoNote (with UBB) that drives the signals and runs the Flash programmer: http://downloads.qi-hardware.com/people/werner/anelok/tmp/mk3-partial/quick-fix-ben.jpg Design files (SolveSpace) and wiring diagram (XFig) are here: https://gitlab.com/anelok/mexp/tree/master/quick After fixing a few small soldering problems, I got this: root@BenNanoNote:~# ./cmcu Cortex M0+ AP #1 ID 0x001c0020 (MDM-AP) AP #0 ID 0x04770031 (AHB-AP) Mass-erase: yes, secure: no, backdoor: no SDID 0x26151502: Kinetis KL26 rev 1.10, 128 kB Flash, 16 kB RAM, 32-pin UID 0060-00691014-27874e45 root@BenNanoNote:~# ./smcu Cortex M0+ AP #1 ID 0x001c0020 (MDM-AP) AP #0 ID 0x04770031 (AHB-AP) Mass-erase: yes, secure: no, backdoor: no SDID 0x16151502: Kinetis KL16 rev 1.10, 128 kB Flash, 16 kB RAM, 32-pin UID 0033-00540007-39494e45 Next is adding the remaining components, restructuring the firmware for the new dual MCU design, and then adapting the SWD code for the RF MCU. - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
