feat(voxl2): Added i2cdetect system command to voxl2-slpi build. Needed to implement the required i2c API for it.

Also, changed the printf into PX4_INFO so the output can be seen for Qurt platforms.

src/lib/drivers/device/qurt/I2C.cpp

@@ -158,10 +158,12 @@ out:
 }
 
 void
-I2C::set_device_address(int address)
+I2C::set_device_address(int address, bool log)
 {
 	if ((_i2c_fd != PX4_ERROR) && (_set_i2c_address != NULL)) {
-		PX4_INFO("Set i2c address 0x%x, fd %d", address, _i2c_fd);
+		if (log) {
+			PX4_INFO("Set i2c address 0x%x, fd %d", address, _i2c_fd);
+		}
 
 		pthread_mutex_lock(_mutex);
 		_set_i2c_address(_i2c_fd, address);

src/lib/drivers/device/qurt/I2C.hpp

@@ -103,7 +103,7 @@ protected:
 	 */
 	virtual int	probe() { return PX4_OK; }
 
-	virtual void set_device_address(int address);
+	virtual void set_device_address(int address, bool log = true);
 
 	/**
 	 * Perform an I2C transaction to the device.

src/systemcmds/i2cdetect/i2cdetect.cpp

@@ -50,7 +50,7 @@ namespace i2cdetect
 
 int detect(int bus)
 {
-	printf("Scanning I2C bus: %d\n", bus);
+	PX4_INFO("Scanning I2C bus: %d", bus);
 
 	int ret = PX4_ERROR;
 
@@ -62,15 +62,17 @@ int detect(int bus)
 		return PX4_ERROR;
 	}
 
-	printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f\n");
+	// Line buffer for building up output
+	char line[80];
+	int pos = 0;
+
+	PX4_INFO("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f");
 
 	for (int i = 0; i < 128; i += 16) {
-		printf("%02x: ", i);
+		pos = snprintf(line, sizeof(line), "%02x: ", i);
 
 		for (int j = 0; j < 16; j++) {
 
-			fflush(stdout);
-
 			uint8_t addr = i + j;
 
 			unsigned retry_count = 0;
@@ -115,14 +117,14 @@ int detect(int bus)
 			} while (retry_count++ < retries);
 
 			if (found) {
-				printf("%02x ", addr);
+				pos += snprintf(line + pos, sizeof(line) - pos, "%02x ", addr);
 
 			} else {
-				printf("-- ");
+				pos += snprintf(line + pos, sizeof(line) - pos, "-- ");
 			}
 		}
 
-		printf("\n");
+		PX4_INFO("%s", line);
 	}
 
 	px4_i2cbus_uninitialize(i2c_dev);