auracaster/hci_uart_iso_timesync
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Verify timestamp from audio sync timer capture - might be a hardware race condition

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This commit is contained in:
Matthias Ringwald
2024-11-21 16:09:10 +01:00
parent 9b3b53fd3c
commit 5b81df6507
1 changed files with 28 additions and 7 deletions
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src/main.c
+28 -7
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@@ -506,30 +506,51 @@ int main(void)
buf = net_buf_get(&rx_queue, K_FOREVER); buf = net_buf_get(&rx_queue, K_FOREVER);
#if DT_NODE_HAS_STATUS(TIMESYNC_GPIO, okay)
// ISO RX Measurement Code // ISO RX Measurement Code
const uint8_t * packet = buf->data; const uint8_t * packet = buf->data;
if (packet[0] == H4_ISO){ if (packet[0] == H4_ISO){
// Get current time uint32_t timestamp_toggle_us;
uint32_t timestamp_toggle_us = audio_sync_timer_capture();
// Lock interrups
uint32_t key = arch_irq_lock();
while (1){
// Get current time once
timestamp_toggle_us = audio_sync_timer_capture();
// Get current time again
uint32_t timestamp_toggle_us_verify = audio_sync_timer_capture();
// check if time didn't jump
int32_t timestamp_delta = (int32_t) (timestamp_toggle_us_verify - timestamp_toggle_us);
if ((timestamp_delta >= 0) && (timestamp_delta < 10)){
break;
}
}
// Toggle // Toggle
#if DT_NODE_HAS_STATUS(TIMESYNC_GPIO, okay)
gpio_pin_toggle_dt( &timesync_pin ); gpio_pin_toggle_dt( &timesync_pin );
#endif
// Unlock interrupts
arch_irq_unlock(key);
// get rx timestamp = sdu sync reference: Packet Type (1) | ISO Header (4) | Timestamp (if TS flag is set) // get rx timestamp = sdu sync reference: Packet Type (1) | ISO Header (4) | Timestamp (if TS flag is set)
uint32_t timestamp_sdu_sync_reference_us = little_endian_read_32(packet, 5); uint32_t timestamp_sdu_sync_reference_us = little_endian_read_32(packet, 5);
// calculate time of toggle relative to sdu sync reference (usually negative as the packet is received before it should be played) // calculate time of toggle relative to sdu sync reference (usually negative as the packet is received before it should be played)
int32_t delta_us = (int32_t)(timestamp_toggle_us - timestamp_sdu_sync_reference_us); int32_t delta_us = (int32_t)(timestamp_toggle_us - timestamp_sdu_sync_reference_us);
// convert to string
// convert to string and send over UART and RTT
char delta_string[10]; char delta_string[10];
snprintf(delta_string, sizeof(delta_string), "R%+05d!", delta_us); snprintf(delta_string, sizeof(delta_string), "R%+05d!", delta_us);
// send over UART
for (size_t i = 0; delta_string[i] != '\0'; i++) { for (size_t i = 0; delta_string[i] != '\0'; i++) {
uart_poll_out(gmap_uart_dev, delta_string[i]); uart_poll_out(gmap_uart_dev, delta_string[i]);
} }
// send over RTT
LOG_INF("Toggle %8u - SDU Sync Reference %8u -> delta %s", timestamp_toggle_us, timestamp_sdu_sync_reference_us, delta_string); LOG_INF("Toggle %8u - SDU Sync Reference %8u -> delta %s", timestamp_toggle_us, timestamp_sdu_sync_reference_us, delta_string);
} }
#endif
err = h4_send(buf); err = h4_send(buf);
if (err) { if (err) {