diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9bd26e839c..dcb33b67e6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -132,10 +132,10 @@ cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
 set(CMAKE_BUILD_TYPE "" CACHE STRING "build type")
 set_property(CACHE CMAKE_BUILD_TYPE PROPERTY
 	STRINGS ";Debug;Release;RelWithDebInfo;MinSizeRel")
-set(CONFIG "nuttx_px4fmu-v2_default" CACHE STRING "desired configuration")
+set(CONFIG "nuttx_px4fmu-v4_default" CACHE STRING "desired configuration")
 file(GLOB_RECURSE configs RELATIVE cmake/configs "cmake/configs/*.cmake")
 set_property(CACHE CONFIG PROPERTY STRINGS ${configs})
-set(THREADS "4" CACHE STRING
+set(THREADS "8" CACHE STRING
 	"number of threads to use for external build processes")
 set(DEBUG_PORT "/dev/ttyACM0" CACHE STRING "debugging port")
 
diff --git a/nuttx-configs/px4fmu-v4/include/board.h b/nuttx-configs/px4fmu-v4/include/board.h
index 1eb9fc9146..f882795bb3 100755
--- a/nuttx-configs/px4fmu-v4/include/board.h
+++ b/nuttx-configs/px4fmu-v4/include/board.h
@@ -257,9 +257,10 @@
 #define GPIO_SPI1_MOSI	(GPIO_SPI1_MOSI_1|GPIO_SPEED_50MHz)
 #define GPIO_SPI1_SCK	(GPIO_SPI1_SCK_1|GPIO_SPEED_50MHz)
 
+
 #define GPIO_SPI2_MISO	(GPIO_SPI2_MISO_1|GPIO_SPEED_50MHz)
 #define GPIO_SPI2_MOSI	(GPIO_SPI2_MOSI_1|GPIO_SPEED_50MHz)
-#define GPIO_SPI2_SCK	(GPIO_SPI2_SCK_2|GPIO_SPEED_50MHz)
+#define GPIO_SPI2_SCK	(GPIO_SPI2_SCK_1|GPIO_SPEED_50MHz)
 
 /************************************************************************************
  * Public Data
diff --git a/src/drivers/boards/px4fmu-v4/board_config.h b/src/drivers/boards/px4fmu-v4/board_config.h
index f5ba9bb8df..7e554c2a74 100644
--- a/src/drivers/boards/px4fmu-v4/board_config.h
+++ b/src/drivers/boards/px4fmu-v4/board_config.h
@@ -73,7 +73,7 @@ __BEGIN_DECLS
 /* LEDs */
 
 #define GPIO_LED1		(GPIO_OUTPUT|GPIO_OPENDRAIN|GPIO_SPEED_50MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTB|GPIO_PIN11)
-#define GPIO_LED2		(GPIO_OUTPUT|GPIO_OPENDRAIN|GPIO_SPEED_50MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTB|GPIO_PIN10)
+#define GPIO_LED2		(GPIO_OUTPUT|GPIO_OPENDRAIN|GPIO_SPEED_50MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTB|GPIO_PIN1)
 #define GPIO_LED3		(GPIO_OUTPUT|GPIO_OPENDRAIN|GPIO_SPEED_50MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTB|GPIO_PIN3)
 
 #define GPIO_LED_RED 	GPIO_LED1
diff --git a/src/drivers/boards/px4fmu-v4/px4fmu_init.c b/src/drivers/boards/px4fmu-v4/px4fmu_init.c
index 12f107b308..d98b629d74 100644
--- a/src/drivers/boards/px4fmu-v4/px4fmu_init.c
+++ b/src/drivers/boards/px4fmu-v4/px4fmu_init.c
@@ -288,7 +288,6 @@ __EXPORT int nsh_archinitialize(void)
 	SPI_SETMODE(spi1, SPIDEV_MODE3);
 	SPI_SELECT(spi1, PX4_SPIDEV_GYRO, false);
 	SPI_SELECT(spi1, PX4_SPIDEV_HMC, false);
-	SPI_SELECT(spi1, PX4_SPIDEV_BARO, false);
 	SPI_SELECT(spi1, PX4_SPIDEV_MPU, false);
 	up_udelay(20);
 
@@ -306,10 +305,11 @@ __EXPORT int nsh_archinitialize(void)
 	 * and de-assert the known chip selects. */
 
 	// XXX start with 10.4 MHz in FRAM usage and go up to 37.5 once validated
-	SPI_SETFREQUENCY(spi2, 12 * 1000 * 1000);
+	SPI_SETFREQUENCY(spi2, 1 * 1000 * 1000);
 	SPI_SETBITS(spi2, 8);
 	SPI_SETMODE(spi2, SPIDEV_MODE3);
 	SPI_SELECT(spi2, SPIDEV_FLASH, false);
+	SPI_SELECT(spi2, PX4_SPIDEV_BARO, false);
 
 #ifdef CONFIG_MMCSD
 	/* First, get an instance of the SDIO interface */
diff --git a/src/drivers/ms5611/ms5611_nuttx.cpp b/src/drivers/ms5611/ms5611_nuttx.cpp
index 91dd785bc6..8c950b5df8 100644
--- a/src/drivers/ms5611/ms5611_nuttx.cpp
+++ b/src/drivers/ms5611/ms5611_nuttx.cpp
@@ -829,7 +829,7 @@ struct ms5611_bus_option {
 	{ MS5611_BUS_SPI_EXTERNAL, "/dev/ms5611_spi_ext", &MS5611_spi_interface, PX4_SPI_BUS_EXT, NULL },
 #endif
 #ifdef PX4_SPIDEV_BARO
-	{ MS5611_BUS_SPI_INTERNAL, "/dev/ms5611_spi_int", &MS5611_spi_interface, PX4_SPI_BUS_SENSORS, NULL },
+	{ MS5611_BUS_SPI_INTERNAL, "/dev/ms5611_spi_int", &MS5611_spi_interface, PX4_SPI_BUS_RAMTRON, NULL },
 #endif
 #ifdef PX4_I2C_BUS_ONBOARD
 	{ MS5611_BUS_I2C_INTERNAL, "/dev/ms5611_int", &MS5611_i2c_interface, PX4_I2C_BUS_ONBOARD, NULL },
@@ -902,6 +902,8 @@ crc4(uint16_t *n_prom)
 bool
 start_bus(struct ms5611_bus_option &bus)
 {
+	warnx("start_bus id %u", (unsigned)bus.busid);
+
 	if (bus.dev != nullptr) {
 		errx(1, "bus option already started");
 	}
@@ -909,6 +911,8 @@ start_bus(struct ms5611_bus_option &bus)
 	prom_u prom_buf;
 	device::Device *interface = bus.interface_constructor(prom_buf, bus.busnum);
 
+	warnx("init ms5611 on bus id %u", (unsigned)bus.busid);
+
 	if (interface->init() != OK) {
 		delete interface;
 		warnx("no device on bus %u", (unsigned)bus.busid);
@@ -923,6 +927,8 @@ start_bus(struct ms5611_bus_option &bus)
 		return false;
 	}
 
+	warnx("open ms5611 on bus %u", (unsigned)bus.busid);
+
 	int fd = open(bus.devpath, O_RDONLY);
 
 	/* set the poll rate to default, starts automatic data collection */
diff --git a/src/drivers/ms5611/ms5611_spi.cpp b/src/drivers/ms5611/ms5611_spi.cpp
index 78192c3a98..9cb6880201 100644
--- a/src/drivers/ms5611/ms5611_spi.cpp
+++ b/src/drivers/ms5611/ms5611_spi.cpp
@@ -149,6 +149,7 @@ MS5611_SPI::init()
 
 	if (ret != OK) {
 		DEVICE_DEBUG("SPI init failed");
+		warnx("SPI::init failed");
 		goto out;
 	}
 
@@ -157,6 +158,7 @@ MS5611_SPI::init()
 
 	if (ret != OK) {
 		DEVICE_DEBUG("reset failed");
+		warnx("SPI::reset failed");
 		goto out;
 	}
 
@@ -165,6 +167,7 @@ MS5611_SPI::init()
 
 	if (ret != OK) {
 		DEVICE_DEBUG("prom readout failed");
+		warnx("SPI::prom readout failed");
 		goto out;
 	}
 
@@ -261,6 +264,7 @@ MS5611_SPI::_read_prom()
 		}
 
 		//DEVICE_DEBUG("prom[%u]=0x%x", (unsigned)i, (unsigned)_prom.c[i]);
+		warnx("prom[%u]=0x%x", (unsigned)i, (unsigned)_prom.c[i]);
 	}
 
 	/* calculate CRC and return success/failure accordingly */
@@ -268,10 +272,12 @@ MS5611_SPI::_read_prom()
 
 	if (ret != OK) {
 		DEVICE_DEBUG("crc failed");
+		warnx("crc failed");
 	}
 
 	if (all_zero) {
 		DEVICE_DEBUG("prom all zero");
+		warnx("prom all zero");
 		ret = -EIO;
 	}