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First operational test version, provides correct readings (as far as tests were possible)

This commit is contained in:
Lorenz Meier 2013-07-25 11:16:25 +02:00
parent edcd25b5ed
commit 830dff9b6a
1 changed files with 20 additions and 20 deletions
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40
src/drivers/meas_airspeed/meas_airspeed.cpp
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@ -91,18 +91,10 @@
#define I2C_ADDRESS_MS5525DSO 0x77 //0x77/* 7-bit address, addr. pin pulled low */
/* Register address */
#define ADDR_RESET_CMD 0x1E /* write to this address to reset chip */
#define ADDR_CMD_CONVERT_D1 0x48 /* write to this address to start temperature conversion */
#define ADDR_CMD_CONVERT_D2 0x58 /* write to this address to start pressure conversion */
#define ADDR_DATA 0x00 /* address of 3 bytes / 32bit pressure data */
#define ADDR_PROM_SETUP 0xA0 /* address of 8x 2 bytes factory and calibration data */
#define ADDR_PROM_C1 0xA2 /* address of 6x 2 bytes calibration data */
/**
* The Eagle Tree Airspeed V3 cannot provide accurate reading below speeds of 15km/h.
* You can set this value to 12 if you want a zero reading below 15km/h.
*/
#define MIN_ACCURATE_DIFF_PRES_PA 0
#define ADDR_READ_MR 0x00 /* write to this address to start conversion */
#define ADDR_READ_DF2 0x00 /* read from this address to read pressure only */
#define ADDR_READ_DF3 0x01
#define ADDR_READ_DF4 0x02 /* read from this address to read pressure and temp */
/* Measurement rate is 100Hz */
#define CONVERSION_INTERVAL (1000000 / 100) /* microseconds */
@ -143,7 +135,7 @@ MEASAirspeed::measure()
/*
* Send the command to begin a measurement.
*/
uint8_t cmd = ADDR_RESET_CMD;
uint8_t cmd = 0;
ret = transfer(&cmd, 1, nullptr, 0);
if (OK != ret) {
@ -163,7 +155,8 @@ MEASAirspeed::collect()
int ret = -EIO;
/* read from the sensor */
uint8_t val[2] = {0, 0};
uint8_t val[4] = {0, 0, 0, 0};
perf_begin(_sample_perf);
@ -174,18 +167,24 @@ MEASAirspeed::collect()
return ret;
}
uint16_t diff_pres_pa = val[1] << 8 | val[0];
uint8_t status = val[0] & 0xC0;
if (diff_pres_pa < _diff_pres_offset + MIN_ACCURATE_DIFF_PRES_PA) {
diff_pres_pa = 0;
} else {
diff_pres_pa -= _diff_pres_offset;
if (status == 2) {
log("err: stale data");
} else if (status == 3) {
log("err: fault");
}
uint16_t diff_pres_pa = (val[1]) | ((val[0] & ~(0xC0)) << 8);
uint16_t temp = (val[3] & 0xE0) << 8 | val[2];
diff_pres_pa = abs(diff_pres_pa - (16384 / 2.0f));
diff_pres_pa -= _diff_pres_offset;
// XXX we may want to smooth out the readings to remove noise.
_reports[_next_report].timestamp = hrt_absolute_time();
_reports[_next_report].temperature = temp;
_reports[_next_report].differential_pressure_pa = diff_pres_pa;
// Track maximum differential pressure measured (so we can work out top speed).
@ -403,6 +402,7 @@ test()
warnx("periodic read %u", i);
warnx("diff pressure: %d pa", report.differential_pressure_pa);
warnx("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature);
}
errx(0, "PASS");