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  // UART configuration
  uart_config_t uart_config = {
  .baud_rate = UPDI_BAUD,
  .data_bits = UART_DATA_8_BITS,
  .parity = UART_PARITY_EVEN,
  .stop_bits = UART_STOP_BITS_2,
  .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
  .rx_flow_ctrl_thresh = 0,
  .source_clk = UART_SCLK_APB,
  };

  // Configure UART parameters
  uart_param_config(UPDI_UART_NUM, &uart_config);
  // Set UART pins
  uart_set_pin(UPDI_UART_NUM, UPDI_RX_PIN, UPDI_TX_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
  // Install UART driver
  uart_driver_install(UPDI_UART_NUM, 1024 * 2, 0, 0, NULL, 0);

  // Set UART read timeout
  uart_set_rx_timeout(UPDI_UART_NUM, 50);
  const gpio_config_t pin_cfg {
    .pin_bit_mask = (1ul << GPIO_NUM_8) | (1ul << GPIO_NUM_2),
    .mode = GPIO_MODE_INPUT_OUTPUT_OD, // Input and Output w/ open-drain!
    .pull_up_en = GPIO_PULLUP_ENABLE, // Open-drain requires a pull-up.
    .pull_down_en = GPIO_PULLDOWN_DISABLE,
    .intr_type = GPIO_INTR_DISABLE
  };

  gpio_config(&pin_cfg);

  esp_rom_gpio_connect_out_signal(UPDI_TX_PIN, UART_PERIPH_SIGNAL(UPDI_UART_NUM, SOC_UART_TX_PIN_IDX), false, false);
  esp_rom_gpio_connect_in_signal(UPDI_RX_PIN, UART_PERIPH_SIGNAL(UPDI_UART_NUM, SOC_UART_RX_PIN_IDX), false);    

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bool COM_Open(const updiprog_com_port_t com_port) {
  esp_err_t err;

  // Configure UPDI Pin as Free-floating OpenDrain Output
  err = gpio_config(&(gpio_config_t){
      .pin_bit_mask = ((uint64_t) 1) << com_port.gpio_num,
      .mode         = GPIO_MODE_INPUT_OUTPUT_OD, // Input and Output w/ open-drain!
      .pull_up_en   = GPIO_PULLUP_DISABLE,       // Open-drain requires a pull-up.
      .pull_down_en = GPIO_PULLDOWN_DISABLE,
      .intr_type    = GPIO_INTR_DISABLE,
  });
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "Failed to configure GPIO for UPDI, error code: 0x%X (%s)", err, esp_err_to_name(err));
    return false;
  }

  // Instantiate UART with 8E2 Polarity
  err = uart_param_config(
      com_port.uart_port,
      &(uart_config_t){
          .baud_rate = com_port.baud_rate,
          .data_bits = UART_DATA_8_BITS,
          .parity    = UART_PARITY_EVEN,
          .stop_bits = UART_STOP_BITS_2,
          .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
      }
  );
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "Failed to configure UART params for UPDI, error code: 0x%X (%s)", err, esp_err_to_name(err));
    return false;
  }

  err = uart_driver_install(com_port.uart_port, UPDI_RX_BUFFER_SIZE, 0, 0, NULL, 0);
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "Failed to install UART driver for UPDI, error code: 0x%X (%s)", err, esp_err_to_name(err));
    return false;
  }

  // Mux the UART Tx and Rx inputs to the GPIO pin via GPIO Matrix
  // Stolen from https://esp32.com/viewtopic.php?t=1089
  esp_rom_gpio_connect_out_signal(com_port.gpio_num, UART_PERIPH_SIGNAL(com_port.uart_port, SOC_UART_TX_PIN_IDX), false, false);
  esp_rom_gpio_connect_in_signal(com_port.gpio_num, UART_PERIPH_SIGNAL(com_port.uart_port, SOC_UART_RX_PIN_IDX), false);

  return true;
}

int COM_Write(const updiprog_com_port_t com_port, const void *const data, const uint16_t len) {
  const int bytes_written = uart_write_bytes(com_port.uart_port, data, len);
  return bytes_written >= 0 ? 0 : bytes_written;
}

int COM_Read(const updiprog_com_port_t com_port, void *const data, const uint16_t len) {
  (void) uart_flush(com_port.uart_port);

  // Read and return num bytes
  return uart_read_bytes(com_port.uart_port, data, len, pdMS_TO_TICKS(((16 * len * 1000 / com_port.baud_rate) + 1) + 30));
}

void COM_Close(const updiprog_com_port_t com_port) {
  const esp_err_t err = uart_driver_delete(com_port.uart_port);
  if (err != ESP_OK) {
    ESP_LOGW(TAG, "Could not delete UART driver for UART port %d", com_port.uart_port);
  }

  // not important to reset GPIO at this time
}