STM32
https://en.wikipedia.org/wiki/STM32#Part_number_decoding
The original Espruino's firmware (see https://www.espruino.com/Original#advanced-reflashing) can be flashed via the USART breakout near the USB connector.
See also https://github.com/espruino/Espruino/blob/master/boards/ESPRUINOBOARD.py for peripheral connections in case you'd want to replicate them.
devices = {
'OSC' : { 'pin_in' : 'D0',
'pin_out' : 'D1' },
'OSC_RTC' : { 'pin_in' : 'C14',
'pin_out' : 'C15' },
'LED1' : { 'pin' : 'A13' },
'LED2' : { 'pin' : 'A14' },
'LED3' : { 'pin' : 'A15' },
'BTN1' : { 'pin' : 'B12' },
'USB' : { 'pin_disc' : 'C13',
'pin_dm' : 'A11',
'pin_dp' : 'A12' },
'SD' : { 'pin_cs' : 'D2',
'pin_di' : 'B15',
'pin_do' : 'B14',
'pin_clk' : 'B13' },
'BLUETOOTH' : { 'pin_tx' : 'A9',
'pin_rx' : 'A10' },
};The board can also be programmed via TinyGo https://tinygo.org/microcontrollers/bluepill/
Note that there are a number of bluepills that have cloned chips and incorrect resistors; it may be an ordeal to source dev boards that are of high quality. I'll put links here when I do find some that I'm comfortable enough to recommend.
- Convert STM32F103c8T6 into a CMSIS-DAP programmer https://github.com/mick909/stm32-dap
- https://mvdlande.wordpress.com/2015/10/05/cmsis-dap-on-a-cheap-st-link-v2-mini-adapter/
The board can be programmed with Epsruino: http://www.espruino.com/ReferenceNUCLEOF401RE#firmware-updates
See also https://github.com/espruino/Espruino/blob/master/boards/NUCLEOF411RE.py for the pin definitions.
devices = {
'OSC' : { 'pin_1' : 'H0', # MCO from ST-LINK fixed at 8 Mhz, boards rev MB1136 C-02
'pin_2' : 'H1' },
'OSC_RTC' : { 'pin_1' : 'C14', # MB1136 C-02 corresponds to a board configured with on-board 32kHz oscillator
'pin_2' : 'C15' },
'LED1' : { 'pin' : 'A5' },
'BTN1' : { 'pin' : 'C13',
'inverted' : True, # 1 when unpressed, 0 when pressed! (Espruino board is 1 when pressed)
'pinstate': 'IN_PULLUP', # to specify INPUT, OUPUT PULL_UP PULL_DOWN..
},
'JTAG' : {
'pin_MS' : 'A13',
'pin_CK' : 'A14',
'pin_DI' : 'A15'
},
# 'USB' : { 'pin_otg_pwr' : 'C0',
# 'pin_dm' : 'A11',
# 'pin_dp' : 'A12',
# 'pin_vbus' : 'A9',
# 'pin_id' : 'A10', },
'NUCLEO_A' : [ 'A0','A1','A4','B0','C1','C0' ],
'NUCLEO_D' : [ 'A3','A2','A10','B3','B5','B4','B10','A8','A9','C7','B6','A7','A6','A5','B9','B8' ],
};