LibOpenCM3 Repo
Arm’s C/C++ Compiler toolchain
Installing arm compiler
tar xjf gcc-arm-none-eabi-9-2019-q4-major-x86_64-linux.tar.bz2
mv gcc-arm-none-eabi-9-2019-q4-major gcc-arm
sudo su
mv gcc-arm /opt
vim ~/.bashrc
vim ~/.bashrc
# arm compiler
export PATH=$PATH:/opt/gcc-arm/bin
source ~/.bashrc
Install it before libs
sudo apt-get install libusb-1.0-0-dev
sudo apt-get install cmake
Open source version of the STMicroelectronics Stlink Tools
cd ~
git clone https://github.com/texane/stlink.git
cd ./stlink
make
cd build/Release/
sudo make install
Configure the Path
vim ~/.bashrc
# stlinl-tools
export PATH=$PATH:$HOME/stlink/build/Release
export LD_LIBRARY_PATH=/usr/local/lib
source ~/.bashrc
Check the st-flash version
st-flash --version
v1.5.1-50-g3690de9
Connect STM32 to the USB port
st-info --probe
Found 1 stlink programmers
serial: 2d3f0f0029135147324d4e00
openocd: "\x2d\x3f\x0f\x00\x29\x13\x51\x47\x32\x4d\x4e\x00"
flash: 65536 (pagesize: 1024)
sram: 20480
chipid: 0x0410
descr: F1 Medium-density device
Read
Reads device's flash memory starting at address 0x8000000, and saves 0x1000 (4K) worth data to a file named saved.img
st-flash read ./saved.img 0x8000000 0x1000
st-flash 1.5.1-50-g3690de9
2019-12-10T23:30:11 INFO common.c: Loading device parameters....
2019-12-10T23:30:11 INFO common.c: Device connected is: L43x/L44x device, id 0x10016435
2019-12-10T23:30:11 INFO common.c: SRAM size: 0xc000 bytes (48 KiB), Flash: 0x40000 bytes (256 KiB) in pages of 2048 bytes
To open de the file install hexedit Ctrl-X: save and exit Ctrl-C: exit without saving
sudo apt install hexedit
hexedit saved.img
Writing at the same address
st-flash write ./saved.img 0x8000000
st-flash 1.5.1-50-g3690de9
2019-12-10T23:36:25 INFO common.c: Loading device parameters....
2019-12-10T23:36:25 INFO common.c: Device connected is: L43x/L44x device, id 0x10016435
2019-12-10T23:36:25 INFO common.c: SRAM size: 0xc000 bytes (48 KiB), Flash: 0x40000 bytes (256 KiB) in pages of 2048 bytes
2019-12-10T23:36:25 INFO common.c: Attempting to write 4096 (0x1000) bytes to stm32 address: 134217728 (0x8000000)
Flash page at addr: 0x08000800 erasedEraseFlash - Page:0x1 Size:0x800
2019-12-10T23:36:25 INFO common.c: Finished erasing 2 pages of 2048 (0x800) bytes
2019-12-10T23:36:25 INFO common.c: Starting Flash write for F2/F4/L4
2019-12-10T23:36:25 INFO flash_loader.c: Successfully loaded flash loader in sram
size: 4096
2019-12-10T23:36:26 INFO common.c: Starting verification of write complete
2019-12-10T23:36:26 INFO common.c: Flash written and verified! jolly good!
Erase Flash
st-flash erase
General Purpose Input/Output
Compile it
cd src/stm32/miniblink
make
Force rebuilding
make clobber
make
make flash
gpio_clear(GPIOC,GPIO13); /* LED on */
...
gpio_set(GPIOC,GPIO13); /* LED off */
In Arduino environment
int ledPin = 13; // LED on digital pin 13
digitalWrite(ledPin, HIGH);
...
digitalWrite(ledPin, LOW);
Include libopencm3 headers
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
The rcc.h file is needed for definitions so as to enable the GPIO clock. The gpio.h file is necessary for the remainder:
void gpio_set(uint32_t gpioport, uint16_t gpios);
void gpio_clear(uint32_t gpioport, uint16_t gpios);
uint16_t gpio_get(uint32_t gpioport, uint16_t gpios);
void gpio_toggle(uint32_t gpioport, uint16_t gpios);
uint16_t gpio_port_read(uint32_t gpioport);
void gpio_port_write(uint32_t gpioport, uint16_t data);
void gpio_port_config_lock(uint32_t gpioport, uint16_t gpios);
The gpioport argument can be one of the macros:
Table: libopencm3 GPIO Macros for STM32F103C8T6
| Port Macro | Description |
|---|---|
| GPIOA | GPIO port A |
| GPIOB | GPIO port B |
| GPIOC | GPIO port C |
In the libopencm3 GPIO functions, one or more GPIO bits may be st or cleared at once. Table below shoes supported macros. Note also the macro named GPIO_ALL.
Table: libopencm3 GPIO pin designation macros
| Pin Macro | Definition | Description |
|---|---|---|
| GPIO0 | (1 << 0) | Bit 0 |
| GPIO1 | (1 << 1) | Bit 1 |
| GPIO2 | (1 << 2) | Bit 2 |
| GPIO3 | (1 << 3) | Bit 3 |
| GPIO4 | (1 << 4) | Bit 4 |
| GPIO5 | (1 << 5) | Bit 5 |
| GPIO0 | (1 << 0) | Bit 0 |
| GPIO7 | (1 << 7) | Bit 7 |
| GPIO8 | (1 << 8) | Bit 8 |
| GPIO9 | (1 << 9) | Bit 9 |
| GPIO10 | (1 << 10) | Bit 10 |
| GPIO11 | (1 << 11) | Bit 11 |
| GPIO12 | (1 << 12) | Bit 12 |
| GPIO13 | (1 << 13) | Bit 13 |
| GPIO14 | (1 << 14) | Bit 14 |
| GPIO15 | (1 << 15) | Bit 15 |
| GPIO_ALL | 0xFFFF | All bits 0 through 15 |
OBS: take a look in src/playground/bitwise_shift_left.c code. 0xFFFF is 65535 in decimal
Example:
gpio_cleat(PORTB, GPIO_ALL); // clear all PORTB pins
To lock GPIO I/O definition:
void gpio_port_config_lock(uint32_t gpioport, uint16_t gpios);
After calling it on selected port, the I/O configuration is frozen until the next system reset. Very useful for safety-critical systems where you don't want an errant program to change these. When a selected GPIO is made an input or an output, it is guaranteed to remain so.
Enable clock for the peripheral or GPIO works
rcc_periph_clock_enable(RCC_GPIOC);
You can disable clock on power consuption.
TIP: It you peripheral or GPIO is not working, check it the necessary clocks are enabled
gpio_set_mode(
GPIOC,
GPIO_MODE_OUTPUT_2_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL,
GPIO13
);
GPIO port
See table libopencm3 GPIO Macros for STM32F103C8T6
GPIO Mode Definitions
| Mode Macro Name | Value | Description |
|---|---|---|
| GPIO_MODE_INPUT | 0x00 | Input mode |
| GPIO_MODE_OUTPUT_2_MHZ | 0x02 | Output mode, at 2MHz |
| GPIO_MODE_OUTPUT_10_MHZ | 0x01 | Output mode, at 10MHz |
| GPIO_MODE_OUTPUT_50_MHZ | 0x03 | Output mode, at 50MHz |
I/O Configuration Specializing Macros
| Specialization Macro Name | Value | Description |
|---|---|---|
| GPIO_CNF_INPUT_ANALOG | 0x00 | Analog input mode |
| GPIO_CNF_INPUT_FLOAT | 0x01 | Digital input, floating (default) |
| GPIO_CNF_INPUT_PULL_UPDOWN | 0x02 | Digital input, pull up and down |
| GPIO_CNF_OUTPUT_PUSHPULL | 0x00 | Digital output, push/pull |
| GPIO_CNF_OUTPUT_OPENDRAIN | 0x01 | Digital output, open drain |
| GPIO_CNF_OUTPUT_ALTFN_PUSHPULL | 0x02 | Alternate function output, push/pull |
| GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN | 0x03 | Alternate function output, open drain |
GPIO Pin
See table libopencm3 GPIO pin designation macros