1 files changed, 23 insertions, 2 deletions
diff --git a/src/uart-test/main.c b/src/uart-test/main.c
index 77c17f4..55ec6fb 100644
--- a/src/uart-test/main.c
+++ b/src/uart-test/main.c
@@ -9,24 +9,45 @@
 
 #define DELAY() HAL_Delay(250)
 
+UART_HandleTypeDef *huart;
+
+/*
+ * If a newline is received on UART1 or UART2, redirect output to that UART.
+ */
+void check_uart_rx(UART_HandleTypeDef *this) {
+  uint8_t rx = 0;
+  if (HAL_UART_Receive(this, &rx, 1, 0) == HAL_OK) {
+    if (rx == '\n') {
+      HAL_GPIO_TogglePin(LED_PORT, LED_GREEN);
+
+      huart = this;
+    }
+  }
+}
+
 int
 main()
 {
   uint8_t c = 'a';
-  uint32_t i = 0;
 
   stm_init();
 
+  huart = &huart1;
+
   while (1)
   {
     HAL_GPIO_TogglePin(LED_PORT, LED_YELLOW);
 
-    HAL_UART_Transmit(&huart1, (uint8_t *) &c, 1, 0xff);
+    HAL_UART_Transmit(huart, (uint8_t *) &c, 1, 0xff);
     DELAY();
 
     if (c++ == 'z') {
       c = 'a';
       HAL_GPIO_TogglePin(LED_PORT, LED_BLUE);
     }
+
+    /* Check for UART change request */
+    check_uart_rx(&huart1);
+    check_uart_rx(&huart2);
   }
 }