Yet another alternate firmware b3603 powersupply

This firmware is an attempt to complete the b3603 firmware written by baruch.

Schematics

Bottom board schematics:

Top board schematics:

Regulator Board (bottom)

Control Board (top)

HARDWARE USED

STLINK V2
B3603 Board
CH340 usb to ttl converter with 2014 drivers

Note : The 2023 driver for CH340 has issues so prefer using the 2014 driver as it works perfectly.

Software needed

VS Code with Platform io installed. OR
ST visual programmer (for flashing only)

MCU

The MCU is an STM8S003F3. It is the TSSOP-20 package.

Pinouts

Lets name the different pinout components, left and right are as seen looking at the top board with the 7-segment display up:

MCU
Left connector -- 8 pins left side
Right connector -- 8 pins right side
Serial connector -- 4 pins at left most side
SWIM connector -- 4 pins at the bottom, just left of the buttons
74HC595 #1 -- The one closest to the MCU
74HC595 #2 -- The one furthest from the MCU

Pinout from MCU

![STM8S003F3 TSSOP20 pins](docs/STM8S003F3 pinout.png)

MCU pin	MCU Function	Board Connector	Board Connector Pin	Board Connector Name
Pin 1	UART1_CK/TIM2_CH1/BEEP/(HS) PD4	74HC595	Pin 3	DS
Pin 2	UART1_TX	Serial connector	Pin 2	TX
Pin 3	UART1_RX	Serial connector	Pin 4	RX
Pin 4	NRST	SWIM	Pin 1	SWIM NRST
Pin 5	OSCIN/PA1	74HC595	Pin 11	SHCP
Pin 6	OSCOUT/PA2	74HC595	Pin 12	STCP
Pin 7	Vss (GND)
Pin 8	Vcap
Pin 9	Vdd
Pin 10	SPI_NSS / TIM2_CH3 / PA3 (HS)	CV/CC leds		CV/CC leds
Pin 11	PB5 (T) / I2C_SDA / TIM1_BKIN	Left connector	Pin 7	CV/CC status
Pin 12	PB4 (T) / I2C_SCL / ADC_ETR	Left connector	Pin 6	Enable Output + Red (ON) led
Pin 13	PC3 (HS) / TIM1_CH3 [TLI] [TIM1_CH1N]	Left Connector	Pin 8	Not connected
Pin 14	PC4 (HS) / TIM1_CH4 / CLK_CCO / AIN2 / TIM1_CH2N	Left connector	Pin 1	Iout sense 16(0.01V + Iout0.05)
Pin 15	PC5 (HS) / SPI_SCK / TIM2_CH1	Left connector	Pin 5	Vout set
Pin 16	PC6 (HS) / SPI_MOSI / TIM1_CH1	Left connector	Pin 4	Iout set
Pin 17	PC7 (HS) / SPI_MISO / TIM1_CH2	Button		Buttons
Pin 18	PD1 (HS) / SWIM	SWIM	Pin 3	SWIM & Buttons
Pin 19	PD2 (HS) / AIN3 / TIM2_CH3	Left connector	Pin 2	Vout sense
Pin 20	PD3 (HS) / AIN4 / TIM2_CH2 / ADC_ETR	Left connector	Pin 3	Vin sense (Vin/16)

The buttons are connected in a strange setup where all four are on two pins.

The CV/CC leds are in serial with a lead between them throuh a 10K resistor to pin PA3, by changing the pin between Output HIGH, Output LOW and Input it is possible to make one of them on or both off.

How to upload

Download ST visual Programmer and flash the ihx file using it.
You will need to set the AFR0 flag of OPT2 byte to 1 in the option bytes tab.
Now perform a Program operation.

How to upload and get started with development

Download platform io and create a new project with board as stm8s003f3 , platform as stpl(although we havent used any of the libraries as of yet)
You will also need st visual programmer for some of the steps.
Next connect the st link and upload the program
Perform a read operation in STVP
Now you will need to set the AFR0 flag of OPT2 byte to 1 using stvp.
Now perform a Program operation

Error Codes

E000 -> AFR0 optionbyte not set in stvp

ACKNOWLEDGMENT

A very special thanks to @baruch as he was the original creator of this Firmware and did most of the work.

Also thanks to @UsrnameTaken , would be using his b3606 code to decrease the size of my code.

b3606 memory efficient Firmware by UsrnameTaken

b3603 Firmware by Baruch

bugs

the afr flag is not able to be set from flag as the uart_flush_writes function never returns back.

changes

buttons working

Functions

Main.c

iwatchdog_init() -> void
iwatchdog_tick() -> void
commit_output() ->void
set_name(uint8_t* name) ->void
autocommit() ->void
set_output(uint8_t* s) ->void
set_voltage(uint8_t* s) ->void
set_current(uint8_t* s) ->void
set_autocommit(uint8_t* s) ->void
write_str(const char* prefix , const char* val) ->void
write_onoff(const char* prefix , uint8_t on) ->void
write_millivolt(const char* prefix , uint16_t mv) ->void
write_milliamp(const char* prefix , uint16_t ma) ->void
write_int(const char* prefix , uint16_t val) ->void
_parse_uint(uint8_t* s) ->uint32_t
process_input() ->void
clk_init() ->void
pinout_init() ->void
config_load() ->void
read_state() ->void
ensure_afr0_set() ->void
detect_button_press() ->void

Display.c

SET_DATA(bit)
PULSE_CLOCK()
SAVE_DATA()
display_word(uint16_t word) -> void
display_refresh() -> void
convert_char_to_displaycode(uint8_t ch, uint8_t dot) -> uint8_t
display_show(uint8_t ch1, uint8_t dot1, uint8_t ch2, uint8_t dot2, uint8_t ch3, uint8_t dot3, uint8_t ch4, uint8_t dot4) -> void

Config.c

config_default_system(cfg_system_t *sys) -> void
validate_system_config(cfg_system_t *sys) -> void
config_load_system(cfg_system_t *sys) -> void
config_save_system(cfg_system_t *sys) -> void
config_default_output(cfg_output_t *cfg) -> void
validate_output_config(cfg_output_t *cfg) -> void
config_load_output(cfg_output_t *cfg) -> void
config_save_output(cfg_output_t *cfg) -> void

Eeprom.c

eeprom_unlock_data() -> uint8_t
eeprom_lock() -> void
eeprom_set_afr0() -> uint8_t
eeprom_save_data(uint8_t *dst, uint8_t *src, uint8_t len) -> uint8_t

Uart.c

uart_init() -> void
uart_write_ready() -> uint8_t
uart_write_ch(const char ch) -> void
uart_write_str(const char *str) -> void
int_to_digits(uint16_t val) -> void
uart_write_int(uint16_t val) -> void
int32_to_digits(uint32_t val) -> uint8_t
uart_write_int32(uint32_t val) -> void
uart_write_milliamp(uint16_t val) -> void
uart_write_millivolt(uint16_t val) -> void
uart_write_fixed_point(uint32_t val) -> void
uart_write_from_buf() -> void
uart_read_ch() -> uint8_t
uart_read_to_buf() -> void
uart_drive() -> void
uart_flush_writes() -> void

parse.c

parse_num(uint8_t *s, uint8_t **stop, uint8_t *digits_seen) -> uint8_t
parse_millinum(uint8_t *s) -> uint16_t

outputs.c

pwm_and_timer_init() -> void
cvcc_led_cc() -> void
cvcc_led_cv() -> void
cvcc_led_off() -> void
pwm_from_set() -> uint16_t
control_voltage(cfg_output_t *cfg, cfg_system_t *sys) -> void
control_current(cfg_output_t *cfg, cfg_system_t *sys) -> void
output_commit(cfg_output_t *cfg, cfg_system_t *sys, uint8_t state_constant_current) -> void
output_check_state(cfg_system_t *sys, uint8_t state_constant_current) -> void

adc.c

adc_init() -> void
_adc_start() -> void
adc_start(uint8_t channel) -> void
adc_to_volt(uint16_t adc, calibrate_t *cal) -> uint16_t
_adc_read() -> uint16_t
adc_read() -> uint16_t
adc_channel() -> uint8_t
adc_ready() -> void

fixed point.c

fixed_round(uint32_t x) -> uint32_t

Interfaces

Button Interface

press OK button set output 1.
press OK button when output is on to cycle through parameters
press SET when output on to turn off output
when output is on or off you can change voltage/current values using up and down buttons.
for change of settings like OCP , OVP , default output state use the UART protocol

UART Interface

Configuration

The serial works at 38400 8N1, the low speed is intended to allow MCU to handle the flow without interfering too much with the rest of the work.

Startup

The controller will send a welcome message "B3603 alternative firmware vX.XX"

Commands

All commands are line-feed or carriage-return terminated, if the input buffer is filled with no LF or CR character the entire line is dumped and a message is sent on the output to indicate this failure.

Model Query

Send: "MODEL"
Receive: "MODEL: B3603"

This is just the model information, it is fixed for this firmware at this time as it only runs on a single device. There is however another device that seems to use the same controller board and then the model returned may be different.

Version Query

Send: "VERSION"
Receive: "VERSION: X.X.X"

System Configuration Query

Send: "SYSTEM"
Receive: "SYSTEM:\r\nMODEL: \r\nVERSION: \r\nNAME: \r\nONSTARTUP: <ON/OFF>\r\nAUTOCOMMIT: <YES/NO>\r\n"

Get the system information: model, version, name, auto-on on startup and auto commit.

Commit configuration

Send: "COMMIT"
Receive: "COMMIT: DONE\r\n"

If auto commit is off this command will change the operating parameters according to the changes done since the last commit. If auto commit is on, this command is not going to change anything.

Auto-commit Set

Send: "AUTOCOMMIT <YES/NO>"
Receive: "AUTOMMIT: YES" or "AUTOCOMMIT: NO"

Set the auto commit setting.

Name Set

Send: "SNAME"
Receive: "SNAME: "

Set the name to what the user gave. The size is limited to 16 characters and they must be printable characters.

Calibration Values

Send: "CALIBRATION"
Receive: detailed on calibration, mostly useful to debug and comparison of units

Voltage Capabilities Query

Send: "VLIST"
Receive: "VLIST: 1.0000/12.0000/0.0001"

Returns minimum voltage, maximum voltage and step size.

Current Capabilities Query

Send: "CLIST"
Receive: "CLIST: 0.001/3.000/0.001"

Returns minimum current, maximum current and step size.

Output Enable/Disable

Send: "OUTPUT 0" or "OUTPUT 1"
Receive: "OUTPUT: DISABLED" or "OUTPUT: ENABLED"

OUTPUT0 disables the output and OUTPUT1 enables the output.

Voltage Set

Send: "VOLTAGE X.XXXX"
Receive: "VOLTAGE: SET X.XXXX"

Set the maximum voltage level.

Current Set

Send: "CURRENT X.XXXX"
Receive: "CURRENT: SET X.XXXX"

Set the maximum current level.

Default at startup

Send: "DEFAULT 0" or "DEFAULT 1"
Receive: "DEFAULT: DISABLED" or "DEFAULT: ENABLED"

Set the default for the output at startup, either enabled or disabled.

Default disabled is better for safety, default enabled is useful when the unit powers an always on device and needs to always work without a manual intervention when the power comes back after a power outage.

Over voltage protection

Send: "VSHUTDOWN X.XXXX" or "VSHUTDOWN 0"
Receive: "VSHUTDOWN: X.XXXX" or "VSHUTDOWN: DISABLED"

When a VSHUTDOWN is set and reached the unit will turn off the output to avoid an over-voltage situation. This would be used in a constant current situation by setting the shutdown voltage lower than the max controlled voltage and let the microcontroller shutdown the entire output if the limit is reached.

Over current protection

Send: "CSHUTDOWN 1" or "CSHUTDOWN 0"
Receive: "CSHUTDOWN: ENABLED" or "CSHUTDOWN: DISABLED"

When a CSHUTDOWN is set and reached the unit will shutdown, current overload is considered when we reach the maximum current and the voltage drops by 10% already to handle the current control, at that point it is assumed the load is in short and the output is shutdown.

Query configuration

Send: "CONFIG"
Receive: "CONFIG:\r\nOUTPUT: \r\nVOLTAGE SET: \r\nCURRENT SET: \r\nVOLTAGE SHUTDOWN: \r\nCURRENT SHUTDOWN: \r\n"

Report all the config variables:

Output -- Output enabled "ON" or disabled "OFF"
Voutmax -- Voltage output maximum
Ioutmax -- Current output max as set
Vshutdown -- Voltage set for shutdown, or "DISABLED" for feature disabled
Cshutdown -- Current shutdown enabled "ON" or disabled "OFF"

Status Report

Send: "STATUS"
Receive: "STATUS:\r\nOUTPUT: \r\nVOLTAGE IN: \r\nVOLTAGE OUT: \r\nVOLTAGE OUT: \r\nCONSTANT: \r\n"

Reports all state variables:

Output -- Output enabled "ON" or disabled "OFF"
Vin -- Voltage Input to the unit
Vout -- Actual voltage output
Iout -- Actual current output
CCCV -- "CURRENT" if we are in constant current, "VOLTAGE" if we are in constant voltage

Missing features

Calibration
Lock keys
Save settings to EEPROM, also load them at startup
Watchdog, can we output something on the serial?
Internal notification logic, monitor the output values and notify immediately on non-trivial change (i.e. apply hysteresis so minutiae errors are not noisy)
add AWG for voltag or current

anshchawla521/b3603