diff options
| -rw-r--r-- | ports/esp32/usb.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/ports/esp32/usb.c b/ports/esp32/usb.c index 85a7a11c9..21047fa2b 100644 --- a/ports/esp32/usb.c +++ b/ports/esp32/usb.c @@ -36,6 +36,7 @@ #define CDC_ITF TINYUSB_CDC_ACM_0 static uint8_t usb_rx_buf[CONFIG_USB_CDC_RX_BUFSIZE]; +static uint8_t usb_cdc_connected; static void usb_callback_rx(int itf, cdcacm_event_t *event) { // TODO: what happens if more chars come in during this function, are they lost? @@ -58,6 +59,13 @@ static void usb_callback_rx(int itf, cdcacm_event_t *event) { } } +void usb_callback_line_state_changed(int itf, cdcacm_event_t *event) { + int dtr = event->line_state_changed_data.dtr; + int rts = event->line_state_changed_data.rts; + // If dtr && rts are both true, the CDC is connected to a HOST. + usb_cdc_connected = dtr && rts; +} + void usb_init(void) { // Initialise the USB with defaults. tinyusb_config_t tusb_cfg = {0}; @@ -70,13 +78,20 @@ void usb_init(void) { .rx_unread_buf_sz = 256, .callback_rx = &usb_callback_rx, .callback_rx_wanted_char = NULL, - .callback_line_state_changed = NULL, + .callback_line_state_changed = &usb_callback_line_state_changed, .callback_line_coding_changed = NULL }; + usb_cdc_connected = 0; ESP_ERROR_CHECK(tusb_cdc_acm_init(&amc_cfg)); + } void usb_tx_strn(const char *str, size_t len) { + // If no HOST is connected, we can exit this early. + if (usb_cdc_connected == 0) { + return; + } + while (len) { size_t l = len; if (l > CONFIG_USB_CDC_TX_BUFSIZE) { |