alema/usbc_soldering_iron
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

moved i2c setup to it's own function

Browse Source
This commit is contained in:
Alessandro Mauri 2026-04-18 22:40:26 +02:00
parent 55bee1a5d8
commit 77701636b5
1 changed files with 26 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
fw/main.c
View File

@ -137,6 +137,31 @@ void EXTI15_8_IRQHandler(void)
} }
// Procedure to get hardware I2C working on the CH32X035F8U6
static inline void setup_i2c(void)
{
// Order here matters, first initialize the AFIO and I2C subsystems then
// change register values, do that the other way around and the configuration
// wont take effect
// Enable AFIO (Alternate Function IO)
RCC->APB2PCENR |= RCC_AFIOEN;
// Init I2C
i2c_init(I2C_TARGET, FUNCONF_SYSTEM_CORE_CLOCK, 100000);
// To utilize the I2C bus we need to disable SWD first, since the pins overlap
AFIO->PCFR1 &= ~(0b0111 << 24);
AFIO->PCFR1 |= 0b0100 << 24;
// Map SCL to PC18 and SDA to PC19
AFIO->PCFR1 |= 0b0101 << 2;
// Manually set the I2C pins to Alternate Function IO, CNF=10b, MODE=10b
GPIOC->CFGXR &= ~((0xF << 8) | (0xF << 12)); // first clear the bits
// then set them
GPIOC->CFGXR |= 0b1010 << 8; // PC18
GPIOC->CFGXR |= 0b1010 << 12; // PC19
}
__attribute__((noreturn)) int main(void) __attribute__((noreturn)) int main(void)
{ {
SystemInit(); SystemInit();
@ -165,27 +190,7 @@ __attribute__((noreturn)) int main(void)
Delay_Ms(5000); Delay_Ms(5000);
/* -------- Code to get hardware I2C working on the CH32X035F8U6 -------- */ setup_i2c();
// Order here matters, first initialize the AFIO and I2C subsystems then
// change register values, do that the other way around and the configuration
// wont take effect
// Enable AFIO (Alternate Function IO)
RCC->APB2PCENR |= RCC_AFIOEN;
// Init I2C
i2c_init(I2C_TARGET, FUNCONF_SYSTEM_CORE_CLOCK, 100000);
// To utilize the I2C bus we need to disable SWD first, since the pins overlap
AFIO->PCFR1 &= ~(0b0111 << 24);
AFIO->PCFR1 |= 0b0100 << 24;
// Map SCL to PC18 and SDA to PC19
AFIO->PCFR1 |= 0b0101 << 2;
// Manually set the I2C pins to Alternate Function IO, CNF=10b, MODE=10b
GPIOC->CFGXR &= ~((0xF << 8) | (0xF << 12)); // first clear the bits
// then set them
GPIOC->CFGXR |= 0b1010 << 8; // PC18
GPIOC->CFGXR |= 0b1010 << 12; // PC19
// Configure the IO as an interrupt. // Configure the IO as an interrupt.
// PIN_ENC_B is on port B, channel 11 // PIN_ENC_B is on port B, channel 11