diff --git a/machine/arm/stm32l4xx/interface/uart.c b/machine/arm/stm32l4xx/interface/uart.c
index abf4621..34e42f5 100644
--- a/machine/arm/stm32l4xx/interface/uart.c
+++ b/machine/arm/stm32l4xx/interface/uart.c
@@ -33,52 +33,80 @@ int write_debug_uart(const char *buf, int len) {
 }
 
 void HAL_UART_MspInit(UART_HandleTypeDef *huart) {
-  if (huart->Instance == LPUART1) {
-
-    RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
-    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
-    PeriphClkInit.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_PCLK1;
-
-    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) {
-      return;
-    }
-
-    __HAL_RCC_LPUART1_CLK_ENABLE();
+  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
+  GPIO_InitTypeDef GPIO_InitStruct = {0};
+  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
+  GPIO_InitStruct.Pull = GPIO_NOPULL;
+  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
+
+  if (huart->Instance == USART1) {
+    // TX: PA9 (AF7), RX: PA10 (AF7)
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1;
+    PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
+    __HAL_RCC_USART1_CLK_ENABLE();
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
+    GPIO_InitStruct.Pin = GPIO_PIN_9 | GPIO_PIN_10;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
+
+  } else if (huart->Instance == USART2) {
+    // TX: PA2 (AF7), RX: PA3 (AF7)
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART2;
+    PeriphClkInit.Usart2ClockSelection = RCC_USART2CLKSOURCE_PCLK1;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
+    __HAL_RCC_USART2_CLK_ENABLE();
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
+    GPIO_InitStruct.Pin = GPIO_PIN_2 | GPIO_PIN_3;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
+
+  } else if (huart->Instance == USART3) {
+    // TX: PC10 (AF7), RX: PC11 (AF7)
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART3;
+    PeriphClkInit.Usart3ClockSelection = RCC_USART3CLKSOURCE_PCLK1;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
+    __HAL_RCC_USART3_CLK_ENABLE();
+    __HAL_RCC_GPIOC_CLK_ENABLE();
+    GPIO_InitStruct.Alternate = GPIO_AF7_USART3;
+    GPIO_InitStruct.Pin = GPIO_PIN_10 | GPIO_PIN_11;
+    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
 
-    GPIO_InitTypeDef GPIO_InitStruct = {0};
-    GPIO_InitStruct.Pin = GPIO_PIN_6 | GPIO_PIN_7; // LPUART1_TX, LPUART1_RX
-    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
-    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
-    GPIO_InitStruct.Alternate = GPIO_AF8_LPUART1;
+  } else if (huart->Instance == UART4) {
+    // TX: PA0 (AF8), RX: PA1 (AF8)
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_UART4;
+    PeriphClkInit.Uart4ClockSelection = RCC_UART4CLKSOURCE_PCLK1;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
+    __HAL_RCC_UART4_CLK_ENABLE();
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    GPIO_InitStruct.Alternate = GPIO_AF8_UART4;
+    GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
 
-    HAL_PWREx_EnableVddIO2();
-    __HAL_RCC_GPIOG_CLK_ENABLE();
-    HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
   } else if (huart->Instance == UART5) {
-
-    RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
+    // TX: PC12 (AF8), RX: PD2 (AF8)
     PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_UART5;
     PeriphClkInit.Uart5ClockSelection = RCC_UART5CLKSOURCE_PCLK1;
-    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) {
-      return;
-    }
-
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
     __HAL_RCC_UART5_CLK_ENABLE();
-
-    // Enable GPIO clocks
-    HAL_PWREx_EnableVddIO2();
     __HAL_RCC_GPIOC_CLK_ENABLE();
     __HAL_RCC_GPIOD_CLK_ENABLE();
-
-    GPIO_InitTypeDef GPIO_InitStruct = {0};
-    GPIO_InitStruct.Pin = GPIO_PIN_12; // PC12 == UART5_TX
-    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
-    GPIO_InitStruct.Pull = GPIO_NOPULL;
-    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
     GPIO_InitStruct.Alternate = GPIO_AF8_UART5;
+    GPIO_InitStruct.Pin = GPIO_PIN_12;
     HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
-    // PD2 == UART5_RX
     GPIO_InitStruct.Pin = GPIO_PIN_2;
     HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
+
+  } else if (huart->Instance == LPUART1) {
+    // TX: PG7 (AF8), RX: PG8 (AF8)
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
+    PeriphClkInit.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_PCLK1;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) return;
+    __HAL_RCC_LPUART1_CLK_ENABLE();
+    HAL_PWREx_EnableVddIO2();
+    __HAL_RCC_GPIOG_CLK_ENABLE();
+    GPIO_InitStruct.Alternate = GPIO_AF8_LPUART1;
+    GPIO_InitStruct.Pin = GPIO_PIN_7 | GPIO_PIN_8;
+    HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
   }
 }
diff --git a/options.toml b/options.toml
index 985e288..58f3392 100644
--- a/options.toml
+++ b/options.toml
@@ -13,7 +13,7 @@ type = "Boolean"
 [debug.uart]
 name = "Debug UART"
 description = "Select the UART peripheral to use for debug output."
-type = { type = "String", allowed_values = ["LPUART1", "UART5"] }
+type = { type = "String", allowed_values = ["USART1", "USART2", "USART3", "UART4", "UART5", "LPUART1"] }
 default = "LPUART1"
 
 [tuning]