Bought a new 4525D digital Airspeed Sensor to use with a fixed wing glider. I have a pixhawk 4 flight controller and have connected the sensor directly to the I2C Port. I’ve set the Airspeed pin parameter to 65, the Airspeed use parameter to 1, and have set the right type of sensor in initial setup. The airspeed reading oscillates between 0-1 m/s even if I blow on. I have tried pre flight calibration and it still does not work. Do I need to connect this to the I2C B Port or change any other parameters to get it to work?
My settings for Holybro Pixhawk 4
ARSPD_AUTOCAL, 0
ARSPD_BUS, 2
ARSPD_FBW_MAX, 22
ARSPD_FBW_MIN, 12
ARSPD_OFFSET, 50.06305
ARSPD_PIN, 65
ARSPD_PRIMARY, 0
ARSPD_PSI_RANGE, 1
ARSPD_RATIO, 1.9936
ARSPD_SKIP_CAL, 0
ARSPD_TUBE_ORDER, 0 If set to 0, the top connector of the sensor must be a dynamic pressure. This setting to zero works without drift of speed fluctuations when the plane is stationary
ARSPD_TYPE, 1
The speed Sensor will work better if you apply the level translator PCA9306 Dual Bidirectional I2C Bus and SMBus Voltage-Level Translator
Hi, Im trying to get my 4525DO working on a pixracer GPS/I2C port (connected with in parallel with the Vcc Gnd SCL SDA wires. I have both the standard sensor, and i have the mro sensor with level changing IC installed.
I have had success with the sensor on a holybro Pixhawk4 by connecting the sensor to I2Ca by itself, and leaving the gps connected to the gps port.
I have also had success with the airspeed sensor connected by itself to the pixracer GPS/I2C port.
But when i connect both the gps and airspeed to the pixracer port the gps works but the airspeed does not.
why does the Pixhawk need I2ca and i2cb ports (plus the gps port which also has i2c when each port could potentially connect to 100 devices?
Does anybody have success using an I2C splitter (or parallel wiring) to connect more than one I2c device to a single port?
Hi
in my case I added 2 pullup resistors (2k2 tbc) to use 2 devices on I2C
So a pull up to 3.3v rail with 2k2 ohms on both the scl and sda lines?
Ok, i can try this.
Can i ask where did you learn that this is required? What did i miss?
The controller scheme already has a resistors installed at the SCL and SDA. If you use a level translator, these resistors are necessary. The port Labelled I2CA of Holybro Pixhawk is Bus3 in Ardupilot is not used in the Full Parameter List of Plane, see the link https://ardupilot.org/plane/docs/parameters.html . Can you find this port Bus3 there?
I asked the developers to activate this port but it is not done. You have better English than mine with a Bing accent, ask the developers to activate the port Bus3.
Now I use an analog air speed sensor, connects to the port Labelled CAP & ADC IN into the nest ADC1_SPARE_2 it has Airspd_PIN = 4 in Ardupilot. I did this because of the long distance to the sensor, the i2c interface has a limit on the length of the wire to 300 mm
What kinda length lmit are you talking about I2C sensor, I mean distance between where to ?