Support for PB8/PA12 CAN pin mapping on STM32F042

[sshsphere]

It would be nice if this library natively supported use of PB8 (CAN RX) and PA12 (CAN TX) for the CAN interface.

This code generated from CubeIDE might be helpful:

__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_8;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF4_CAN;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

GPIO_InitStruct.Pin = GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF4_CAN;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

I added this option to the begin function in STM32_CAN.cpp and everything works perfectly

[pazi88]

Ok. Good to know that it works. I'll see what I can do. Some use different way of setting up the pins that are used and in those you can only use the pin pairs that are currently available in the library. I need to think best way to do that.