Psas

Portland State Aerospace Society

2025 Q3

Electromechanical Recovery System

• https://docs.google.com/document/d/1DnytDlZa1X-BaIqlIBrfcuedKocKrCpTfgMspk0twxI/edit?tab=t.0

• https://github.com/psas/lv3.1-recovery/tree/master/controlSystem/RecoveryBoard . . . Kicad files

• https://drive.google.com/file/d/1qRkbDvV0_Ep7_zKsPC3GMgZicTurCPgf/view

^ Kicad

Link to Kicad installation instructions page.

• https://www.kicad.org/download/linux/

^ ERS board TODO

[ ] create board files for ERS board as of LV3.1-recovery

[ ] add device tree code to select and to enable MCU debug UART

[ ] add a DTS compatible type or entity to group GPIOs together in primary ERS dts file

Comparing flash invocation ChibiOS versus Zephyr

ChibiOS ERS make file gives:

ted@localhost:~/projects/psas/psas-avionics/lv3.1-recovery/controlSystem/RecoveryBoard/firmware$ make write
openocd -f toolchain/oocd.cfg -c "program ./build/recovery-firmware.hex verify reset exit"
Open On-Chip Debugger 0.11.0-rc2+dev-00002-g427552c07-dirty (2021-01-30-10:36)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
Info : clock speed 1000 kHz
Info : STLINK V3J8M3B5S1 (API v3) VID:PID 0483:374F
Info : Target voltage: 3.323200
Info : stm32f0x.cpu: hardware has 4 breakpoints, 2 watchpoints
Info : starting gdb server for stm32f0x.cpu on 3333
Info : Listening on port 3333 for gdb connections
target halted due to debug-request, current mode: Thread 
xPSR: 0xc1000000 pc: 0x08000190 msp: 0x20000200
** Programming Started **
Info : device id = 0x10006442
Info : flash size = 256kbytes
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
shutdown command invoked

To flash Zephyr based app using same openocd call gives:

ted@localhost:~/projects/zephyr-project/psas-ers-firmware/samples/hello-world$ openocd -f /home/ted/projects/psas/psas-avionics/lv3.1-recovery/controlSystem/RecoveryBoard/firmware/toolchain/oocd.cfg -c "program ./build/zephyr/zephyr.hex verify reset exit"
Open On-Chip Debugger 0.11.0-rc2+dev-00002-g427552c07-dirty (2021-01-30-10:36)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
Info : clock speed 1000 kHz
Info : STLINK V3J8M3B5S1 (API v3) VID:PID 0483:374F
Info : Target voltage: 3.312000
Info : stm32f0x.cpu: hardware has 4 breakpoints, 2 watchpoints
Info : starting gdb server for stm32f0x.cpu on 3333
Info : Listening on port 3333 for gdb connections
target halted due to debug-request, current mode: Thread 
xPSR: 0xc1000000 pc: 0x08000190 msp: 0x20000200
** Programming Started **
Info : device id = 0x10006442
Info : flash size = 256kbytes
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
shutdown command invoked

^ Debugging With openocd

Got a debugging session working. Observe that an RCC HSE clock initialization step is hanging:

ted@localhost:~/projects/zephyr-project/psas-ers-board-bringup/samples/hello-world$ arm-none-eabi-gdb build/zephyr/zephyr.elf
GNU gdb (Ubuntu 12.1-0ubuntu1~22.04.2) 12.1
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

 . . .

Reading symbols from build/zephyr/zephyr.elf...
(gdb) target extended-remote:3333
Remote debugging using :3333
0x08000b40 in set_up_fixed_clock_sources () at /home/ted/projects/zephyr-project/zephyr/drivers/clock_control/clock_stm32_ll_common.c:645
645			while (LL_RCC_HSE_IsReady() != 1) {
(gdb) bt
#0  0x08000b40 in set_up_fixed_clock_sources () at /home/ted/projects/zephyr-project/zephyr/drivers/clock_control/clock_stm32_ll_common.c:645
#1  stm32_clock_control_init (dev=<optimized out>) at /home/ted/projects/zephyr-project/zephyr/drivers/clock_control/clock_stm32_ll_common.c:819
#2  0x08002f2e in do_device_init (dev=0x80031c8 <__init_malloc_prepare>) at /home/ted/projects/zephyr-project/zephyr/kernel/init.c:333
#3  0x080017fa in z_sys_init_run_level (level=<optimized out>) at /home/ted/projects/zephyr-project/zephyr/kernel/init.c:392
#4  0x0800196e in z_cstart () at /home/ted/projects/zephyr-project/zephyr/kernel/init.c:815
#5  0x080029bc in z_prep_c () at /home/ted/projects/zephyr-project/zephyr/arch/arm/core/cortex_m/prep_c.c:211
#6  0x08000576 in z_arm_reset () at /home/ted/projects/zephyr-project/zephyr/arch/arm/core/cortex_m/reset.S:207
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) quit
A debugging session is active.

	Inferior 1 [Remote target] will be detached.

Quit anyway? (y or n) y
Detaching from program: /home/ted/projects/zephyr-project/psas-ers-board-bringup/samples/hello-world/build/zephyr/zephyr.elf, Remote target
[Inferior 1 (Remote target) detached]

Need to understand why the bit which `LL_RCC_HSE_IsReady()` checks is never being set.

Some forum posts:

(1) https://github.com/zephyrproject-rtos/zephyr/issues/36524

(2) https://lists.zephyrproject.org/g/users/topic/stm32h753_stuck_on_hse_rdy/112297269

Bindings files and Zephyr

• https://docs.zephyrproject.org/latest/build/dts/bindings-intro.html

Newer way of doing things with GPIO properties, Zephyr 4.2.0 . . .

• "./dts/bindings/pinctrl/nxp,s32k3-pinctrl.yaml" 115 lines

^ CAN Bus Sample App

• zephyr/samples/drivers/can/babbling/src

File `zephyr/dts/arm/st/f0/stm32f091.dtsi` defines a node named `can1`. Node is disabled in this overlay file.

^ References

STM32F091 reference manual:

• https://www.st.com/en/microcontrollers-microprocessors/stm32f0-series/documentation.html#