I want to log pressure and temperature values from my Twinstar2. I have just bought and tested the BMP085 sensor in my Paparazzi setup, and I get the BMP_STATUS message in the Messages tool. I have <define name="SENSOR_SYNC_SEND"/> in my airframe file.
I have compared the BMP085 pressure readings to our local weather station run by Bergen University, and the sensor data are close to spot on.
I use freq="8" in baro_bmp.xml, which seems to give four BMP_STATUS messages per second. The pressure values fluctuate a bit, so I modified baro_bmp.c so that it averages a number of readings before sending a message via telemetry. This improved things a lot, and with 20 readings per averaged value I get a very stable plot with a telemetry message approx every 5 seconds. Perhaps averaging as much as 20 readings may not be suitable when the BMP is used as an altimeter, due to the slow refresh rate.
With a small (but improving) C and makefile knowledge I am a bit stuck with regards to finding where the baro_bmp.c compiling instructions are, and which function the sensor code is called from. Could anyone please shed some light on this?