Merge pull request #6 from shufps/non-blocking-rx

uses non-blocking read for asic response

src/drivers/nerd-nos/bm1397.cpp

@@ -362,24 +362,23 @@ bool BM1397_receive_work(uint16_t timeout, asic_result *result)
 {
     uint8_t *rcv_buf = (uint8_t*) result;
 
-    // wait for a response, wait time is pretty arbitrary
-    int received = SERIAL_rx(rcv_buf, 9, timeout);
+    // non blocking read
+    int received = SERIAL_rx_non_blocking(rcv_buf, 9);
 
     if (received < 0)
     {
         Serial.println("Error in serial RX");
         return false;
     }
-    else if (received == 0)
+    else if (!received)
     {
-        // Didn't find a solution, restart and try again
+        // we have not received any data
         return false;
     }
 
     if (received != 9 || rcv_buf[0] != 0xAA || rcv_buf[1] != 0x55)
     {
         Serial.println("Serial RX invalid. Resetting receive buffer ...");
-        //ESP_LOG_BUFFER_HEX(TAG, asic_response_buffer, received);
         SERIAL_clear_buffer();
         return false;
     }

src/drivers/nerd-nos/serial.cpp

@@ -57,6 +57,28 @@ size_t SERIAL_check_for_data() {
     return length;
 }
 
+/// @brief waits for a serial response from the device
+/// @param buf buffer to read data into
+/// @param buf number of ms to wait before timing out
+/// @return number of bytes read, or -1 on error
+int16_t SERIAL_rx_non_blocking(uint8_t *buf, uint16_t size) {
+    // check how much data we have
+    size_t available = SERIAL_check_for_data();
+
+    // no data available, return 0
+    if (!available) {
+        return 0;
+    }
+
+    // check for incomplete data
+    if (available && available < size) {
+        Serial.printf("not returning incomplete data ... %d vs %d\n", (int) available, (int) size);
+        return 0;
+    }
+    // timeout 0 means non_blocking read
+    return SERIAL_rx(buf, size, 0);
+}
+
 
 /// @brief waits for a serial response from the device
 /// @param buf buffer to read data into
@@ -64,13 +86,6 @@ size_t SERIAL_check_for_data() {
 /// @return number of bytes read, or -1 on error
 int16_t SERIAL_rx(uint8_t *buf, uint16_t size, uint16_t timeout_ms)
 {
-    // don't return incomplete data
-    size_t available = SERIAL_check_for_data();
-    if (available && available < size) {
-        Serial.printf("not returning parts of data ... %d vs %d\n", (int) available, (int) size);
-        return 0;
-    }
-
     int16_t bytes_read = uart_read_bytes(UART_NUM_1, buf, size, timeout_ms / portTICK_PERIOD_MS);
     // if (bytes_read > 0) {
     //     printf("rx: ");
@@ -83,21 +98,6 @@ int16_t SERIAL_rx(uint8_t *buf, uint16_t size, uint16_t timeout_ms)
     return bytes_read;
 }
 
-void SERIAL_debug_rx(void)
-{
-    int ret;
-    uint8_t buf[CHUNK_SIZE];
-
-    ret = SERIAL_rx(buf, 100, 20);
-    if (ret < 0)
-    {
-        fprintf(stderr, "unable to read data\n");
-        return;
-    }
-
-    memset(buf, 0, 1024);
-}
-
 void SERIAL_clear_buffer(void)
 {
     uart_flush(UART_NUM_1);

src/drivers/nerd-nos/serial.h

@@ -4,8 +4,8 @@
 
 int SERIAL_send(uint8_t *, int, bool);
 void SERIAL_init(void);
-void SERIAL_debug_rx(void);
 int16_t SERIAL_rx(uint8_t *, uint16_t, uint16_t);
+int16_t SERIAL_rx_non_blocking(uint8_t *buf, uint16_t size);
 void SERIAL_clear_buffer(void);
 void SERIAL_set_baud(int baud);