AP_Baro: new files for VRBRAIN board

libraries/AP_Baro/AP_Baro.h

@@ -90,5 +90,6 @@ private:
 #include "AP_Baro_BMP085.h"
 #include "AP_Baro_HIL.h"
 #include "AP_Baro_PX4.h"
+#include "AP_Baro_VRBRAIN.h"
 
 #endif // __AP_BARO_H__

libraries/AP_Baro/AP_Baro_VRBRAIN.cpp

@@ -0,0 +1,86 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+
+#include <AP_HAL.h>
+
+#if CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
+#include <AP_Baro.h>
+#include "AP_Baro_VRBRAIN.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <drivers/drv_baro.h>
+#include <drivers/drv_hrt.h>
+
+extern const AP_HAL::HAL& hal;
+
+// Public Methods //////////////////////////////////////////////////////////////
+bool AP_Baro_VRBRAIN::init(void)
+{
+    if (_baro_fd <= 0) {
+        _baro_fd = open(BARO_DEVICE_PATH, O_RDONLY);
+        if (_baro_fd < 0) {
+            hal.scheduler->panic("Unable to open " BARO_DEVICE_PATH);
+        }
+
+        /* set the driver to poll at 150Hz */
+        ioctl(_baro_fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_MAX);
+
+        // average over up to 20 samples
+        ioctl(_baro_fd, SENSORIOCSQUEUEDEPTH, 20);
+
+        // give the timer a chance to run and gather one sample
+        hal.scheduler->delay(40);
+        _accumulate();
+    }
+
+    return true;
+}
+
+// Read the sensor
+uint8_t AP_Baro_VRBRAIN::read(void)
+{
+    // try to accumulate one more sample, so we have the latest data
+    _accumulate();
+
+    // consider the baro healthy if we got a reading in the last 0.2s
+    healthy = (hrt_absolute_time() - _last_timestamp < 200000);
+    if (!healthy || _sum_count == 0) {
+        return healthy;
+    }
+
+    _pressure    = (_pressure_sum / _sum_count) * 100.0f;
+    _temperature = _temperature_sum / _sum_count;
+    _pressure_samples = _sum_count;
+    _last_update = (uint32_t)_last_timestamp/1000;
+    _pressure_sum = 0;
+    _temperature_sum = 0;
+    _sum_count = 0;
+
+    return 1;
+}
+
+// accumulate sensor values
+void AP_Baro_VRBRAIN::_accumulate(void)
+{
+    struct baro_report baro_report;
+    while (::read(_baro_fd, &baro_report, sizeof(baro_report)) == sizeof(baro_report) &&
+           baro_report.timestamp != _last_timestamp) {
+		_pressure_sum += baro_report.pressure; // Pressure in mbar
+		_temperature_sum += baro_report.temperature; // degrees celcius
+        _sum_count++;
+        _last_timestamp = baro_report.timestamp;
+    }
+}
+
+float AP_Baro_VRBRAIN::get_pressure() {
+    return _pressure;
+}
+
+float AP_Baro_VRBRAIN::get_temperature() {
+    return _temperature;
+}
+
+#endif // CONFIG_HAL_BOARD

libraries/AP_Baro/AP_Baro_VRBRAIN.h

@@ -0,0 +1,29 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+
+#ifndef __AP_BARO_VRBRAIN_H__
+#define __AP_BARO_VRBRAIN_H__
+
+#include "AP_Baro.h"
+
+class AP_Baro_VRBRAIN : public AP_Baro
+{
+public:
+    bool init();
+    uint8_t read();
+    float get_pressure();
+    float get_temperature();
+
+private:
+    float _temperature;
+    float _pressure;
+    float _pressure_sum;
+    float _temperature_sum;
+    uint32_t _sum_count;
+    void _accumulate(void);
+    void _baro_timer(uint32_t now);
+    uint64_t _last_timestamp;
+    // baro driver handle
+    int _baro_fd;
+};
+
+#endif //  __AP_BARO_VRBRAIN_H__