An experimental LED-strip controller and my first embedded-programming project with C and Go. STM32F103 firmware drives LED brightness with PWM through MOSFETs. A separate controller, such as a Raspberry Pi or ESP8266, sends commands over SPI.

The project explores low-latency lighting controls from gamepads, MIDI, network requests and other inputs. These are experiments and design goals; not every input or transport is complete.

• Experimental hardware and software with known bugs, unused code and unfinished features. It is not a supported, ready-to-use lighting system.
• RGB is not supported.
• The original setup used three LED strips. Other configurations have not been verified here.
• The original notes report unexpectedly high CPU use in the Go controller. The hardware and build notes below retain the other known issues.

PA8, PA9, PA10, PA11 (PA11 is used by USB, so only 3 other pins are available)

Current set up: PA4: SPI1_NSS PA5: SPI1_SCK PA6: SPI1_MISO PA7: SPI1_MOSI

This could probably be changed to other SPI on other pins, but I haven’t checked that.

PA11: D- PA12: D+ USB port on the blue pill is connected to the same pins.

doesn’t work if stm32 connected by itself, works if ground is connected to rpi group (???)

• openocd or Black Magic Probe which implements openocd internaly
• gcc-arm-none-eabi
• newlib

copy openocd files to: /usr/share/openocd/scripts/target/cs32f1x.cfg /usr/share/openocd/scripts/board/cs32f103c8t6.cfg

Connect st-link

make -C my-project make flash -C my-project

start openocd: openocd -f /usr/share/openocd/scripts/board/cs32f103c8t6.cfg

connect to it via gdb: gdb-multiarch –eval-command=”target remote localhost:3333” my-project/your-file.elf

You can also connect to openocd via ‘telnet localhost 4444’ and send some commands to it

msg_type size payload

• set one led
• set all leds
• set some configuration?
• get led value?
• get configuration value(s)

Clock / Prescaler / ARR = timer frequency

clock / desired timer frequency = prescaler * ARR

timer_set_prescaler TIM_PSC

divides the clock

timer_set_period ARR

sets timer ?

• TIM_OC?: Output Compare channel
• TIM_OC?N: ?

• Add another message type to only receive the state, not change it

`

UART2 (TX: PA2, RX: PA3) is most convenient.