Periodically send status

Periodically sends status flags over the USB connection.

Signed-off-by: Nate Karstens <[email protected]>

Author: nkarstens

lib/pbio/drv/usb/usb_stm32.c

@@ -30,8 +30,10 @@ PROCESS(pbdrv_usb_process, "USB");
 
 static uint8_t usb_in_buf[USBD_PYBRICKS_MAX_PACKET_SIZE];
 static uint8_t usb_response_buf[1 + sizeof(uint32_t)];
+static uint8_t usb_status_buf[1 + 1 + sizeof(uint32_t)];
 static volatile uint32_t usb_in_sz;
 static volatile uint32_t usb_response_sz;
+static volatile uint32_t usb_status_sz;
 static volatile bool transmitting;
 
 static USBD_HandleTypeDef husbd;
@@ -144,6 +146,7 @@ static USBD_StatusTypeDef Pybricks_Itf_Init(void) {
     USBD_Pybricks_SetRxBuffer(&husbd, usb_in_buf);
     usb_in_sz = 0;
     usb_response_sz = 0;
+    usb_status_sz = 0;
     transmitting = false;
 
     return USBD_OK;
@@ -195,6 +198,8 @@ static USBD_StatusTypeDef Pybricks_Itf_TransmitCplt(uint8_t *Buf, uint32_t *Len,
 
     if (Buf == usb_response_buf) {
         usb_response_sz = 0;
+    } else if (Buf == usb_status_buf) {
+        usb_status_sz = 0;
     } else {
         ret = USBD_FAIL;
     }
@@ -243,6 +248,9 @@ PROCESS_THREAD(pbdrv_usb_process, ev, data) {
     static PBIO_ONESHOT(pwrdn_oneshot);
     static bool bcd_busy;
     static pbio_pybricks_error_t result;
+    static struct etimer timer;
+    static uint32_t prev_status_flags = ~0;
+    static uint32_t new_status_flags;
 
     PROCESS_POLLHANDLER({
         if (!bcd_busy && pbio_oneshot(!vbus_active, &no_vbus_oneshot)) {
@@ -264,6 +272,8 @@ PROCESS_THREAD(pbdrv_usb_process, ev, data) {
     // Prepare to receive the first packet
     USBD_Pybricks_ReceivePacket(&husbd);
 
+    etimer_set(&timer, 500);
+
     for (;;) {
         PROCESS_WAIT_EVENT();
 
@@ -310,7 +320,22 @@ PROCESS_THREAD(pbdrv_usb_process, ev, data) {
             continue;
         }
 
-        if (usb_response_sz) {
+        new_status_flags = pbsys_status_get_flags();
+
+        // Transmit. Give priority to status updates.
+        if ((new_status_flags != prev_status_flags) || etimer_expired(&timer)) {
+
+            usb_status_buf[0] = USBD_PYBRICKS_MSG_EVENT;
+            usb_status_sz = 1 + pbio_pybricks_event_status_report(&usb_status_buf[1], new_status_flags);
+
+            etimer_restart(&timer);
+            prev_status_flags = new_status_flags;
+
+            transmitting = true;
+            USBD_Pybricks_TransmitPacket(&husbd, usb_status_buf, usb_status_sz);
+
+        } else if (usb_response_sz) {
+
             transmitting = true;
             USBD_Pybricks_TransmitPacket(&husbd, usb_response_buf, usb_response_sz);
         }