rc spi testing

Author: Demo User

examples/src/rc_spi_loopback.c

@@ -18,15 +18,14 @@
 #define SLAVE		0
 
 
-#define SLAVE_MODE	SPI_SLAVE_MODE_AUTO
 #define BUS_MODE	SPI_MODE_0
 #define SPI_SPEED	24000000
 
 int main()
 {
 	char* test_str = "Hello World";
 	int bytes = strlen(test_str);	// get number of bytes in test string
-	uint8_t buf[bytes];		// read buffer
+	uint8_t buf[32];		// read buffer
 	int ret;			// return value
 
 	printf("Make sure the MISO and MOSI lines are connected with\n");
@@ -38,13 +37,26 @@ int main()
 
 	// attempt a string send/receive test
 	printf("Sending  %d bytes: %s\n", bytes, test_str);
-	ret = rc_spi_transfer(BUS, SLAVE, (uint8_t*)test_str, bytes, buf);
-	if(ret<0){
-		printf("send failed\n");
-		rc_spi_close(SLAVE);
-		return -1;
+
+	while(1){
+		//ret = rc_spi_transfer(BUS, SLAVE, (uint8_t*)test_str, bytes, buf);
+		ret = rc_spi_write(BUS, SLAVE, (uint8_t*)test_str, bytes);
+		if(ret<0){
+			printf("send failed\n");
+			rc_spi_close(SLAVE);
+			return -1;
+		}
+		else printf("sent %d bytes: %s\n",bytes, test_str);
+		// read back
+		ret = rc_spi_read(BUS, SLAVE, buf, bytes);
+		if(ret<0){
+			printf("read failed\n");
+			rc_spi_close(SLAVE);
+			return -1;
+		}
+		else printf("Received %d bytes: %s\n",ret, (char*)buf);
+		rc_usleep(10000);
 	}
-	else printf("Received %d bytes: %s\n",ret, buf);
 
 	rc_spi_close(BUS);
 	return 0;

library/include/rc/spi.h

@@ -21,6 +21,15 @@
  *                          RC_SPI_MAX_SPEED, RC_BLUE_SS1_GPIO);
  * ```
  *
+ * pinout on Robotics Cape and BeagleBone Blue:
+ * 1. GND
+ * 2. 3.3V
+ * 3. MOSI (P9_30)
+ * 4. MISO (P9_29)
+ * 5. SCK  (P9_31)
+ * 6. Slave Select
+ *
+ *
  * The slaves can be selected automatically by the SPI Linux driver or manually
  * with rc_spi_select() function. On the Robotics Cape, slave 1 can be used in
  * either mode, but slave 2 must be selected manually. On the BB Blue either

library/src/io/spi.c

@@ -272,7 +272,7 @@ int rc_spi_init_manual_slave(int bus, int slave, int bus_mode, int speed_hz, int
 	state[bus].init[slave] = 1;
 	state[bus].ss_mode[slave] = SS_MODE_MANUAL;
 	state[bus].chip[slave] = chip;
-	state[bus].pin[slave] = chip;
+	state[bus].pin[slave] = pin;
 	state[bus].fd[slave] = fd;
 	state[bus].fd[0] = fd; // just in case we are initializing a slave other than 0 first
 	state[bus].speed[slave] = speed_hz;