Scan both buses

src/drivers/px4flow/px4flow.cpp

@@ -73,12 +73,10 @@
 #include <board_config.h>
 
 /* Configuration Constants */
-#define PX4FLOW_BUS 			PX4_I2C_BUS_ESC//PX4_I2C_BUS_EXPANSION
 #define I2C_FLOW_ADDRESS 		0x42 //* 7-bit address. 8-bit address is 0x84
 //range 0x42 - 0x49
  
 /* PX4FLOW Registers addresses */
-//#define PX4FLOW_REG		0x00	/* Measure Register 0*/
 #define PX4FLOW_REG		0x16	/* Measure Register 22*/
 
 #define PX4FLOW_CONVERSION_INTERVAL 20000 //in microseconds! 20000 = 50 Hz 100000 = 10Hz
@@ -664,7 +662,16 @@ start()
 	}
 
 	/* create the driver */
-	g_dev = new PX4FLOW(PX4FLOW_BUS);
+	g_dev = new PX4FLOW(PX4_I2C_BUS_EXPANSION);
+
+	if (g_dev == nullptr) {
+		goto fail;
+	}
+
+	if (OK != g_dev->init()) {
+		delete g_dev;
+		/* try 2nd bus */
+		g_dev = new PX4FLOW(PX4_I2C_BUS_ESC);
 
 		if (g_dev == nullptr) {
 			goto fail;
@@ -673,6 +680,7 @@ start()
 		if (OK != g_dev->init()) {
 			goto fail;
 		}
+	}
 
 	/* set the poll rate to default, starts automatic data collection */
 	fd = open(PX4FLOW_DEVICE_PATH, O_RDONLY);