Remap and alternate function PB3

[babitsyn]

Cannot run blinky project at PB3 pin. At PC13 blinky project works perfectly because GPIO is default function of this pin. But PB3 default function is JTDO. How to set (or remap) PB3 in OUTPUT_OPEN_DRAIN mode?

[maxgerhardt]

I assume that's on GD32F303CC?

[babitsyn]

No, it is GD32F303CG. But I set GD32F303CC Generic, because it almost same.

[maxgerhardt]

I see. Yes we're definitely missing the remap setting for the default JTAG pins in the core, I will correct it when I'm home. We're missing a call to gpio_pin_remap_config with the JTAG remapping as defined in https://github.com/CommunityGD32Cores/ArduinoCore-GD32/blob/main/system/GD32F30x_firmware/GD32F30x_standard_peripheral/Include/gd32f30x_gpio.h

[babitsyn]

Working code:
// Blinky mod
#include <Arduino.h>
#define LED PB3
static int i=0;
void setup(){
rcu_periph_clock_enable(RCU_AF);
gpio_pin_remap_config(GPIO_SWJ_SWDPENABLE_REMAP, ENABLE);
//gpio_init(GPIOB, GPIO_MODE_OUT_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_3|GPIO_PIN_4);
Serial.begin(115200);
pinMode(LED, OUTPUT_OPEN_DRAIN);
}

void loop(){
digitalWrite(LED, LOW);
//gpio_bit_set(GPIOB, GPIO_PIN_3|GPIO_PIN_4);
delay(500);
//gpio_bit_reset(GPIOB, GPIO_PIN_3|GPIO_PIN_4);
digitalWrite(LED, HIGH);
delay(500);
Serial.println("Blinky nr. " + String(i++));
} // End
PB4 added for test purposes, to be sure if PB3 is broken. Both of "digitalWrite" and "gpio_bit_(re)set" working well.
rcu_periph_clock_enable(RCU_AF); is mandatory!