are there any non OEM compasses compatible with the solo?
- Thread starter pious_greek
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No such thing. Why would you even want to? The solo has two. One is in the leg, the other is built into the pixhawk. Both of them are quite good. There is no reason to change them out. Anything else you put in would likely be inferior.
If you need a new leg compass, I have one I could sell. Otherwise, you don't need one other than if yours goes bad.
i'm putting together a solo from misc parts and stock on hand, the leg compass is the only thing i don't have, and I don't feel like shelling out 30$ for it, at least not before exhausting other options. I'm sure there's a compatible compass.
Sometime ago I partially disassembled my SOLO in order to replace shell. Unwittingly I used a magnetized screw driver around the compass leg. How can I check compass for damage? If I have damaged compass in leg can I use magnetic compass found in
mRobotics' Neo M8N (uBlox) GPS.
mRobotics' Neo M8N (uBlox) GPS.
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are you able to perform the compass calibratation? does it fly in a straight line when you direct it straight? then probably no harm no foul. otherwise, i would suggest first replacing the screw with a non magnetized one or you could try baking the screw at a high temp to demagnitize it.
Thanks for suggestion.
Would still like to learn of any bench test to check for compass deviation or inaccuracy. Would like to know of any wrinkles in using uBlox Neo M8N.
Would still like to learn of any bench test to check for compass deviation or inaccuracy. Would like to know of any wrinkles in using uBlox Neo M8N.
One reason for replacing leg compass might be leg compass has been damaged thru use of magnetic screwdriver.
Another reason to replace leg compass might be superiority of replacement's precision or signal quality.
Thanks, Joe Homer
I had read somewhere that a real world test is to use TOWER to line up the solo with an object using the projected heading on the screen (a red line) and then fly solo straight with the controller to see how far off it is.
the digital compass is an I2C device, just like the battery so in theory you should be able to hook up an arduino to it and request readings. i'm not sure what compass is on the stock solo as i've never removed the rubber shielding, but the chip below was used earlier, I believe it's a honeywell HMC5983, 3 axis compass. that datasheet is here:
https://aerocontent.honeywell.com/a...hures-documents/HMC5983_3_Axis_Compass_IC.pdf
there are some proof of concept arduino libraries if you google it, and there is a breakout board that may be compatible with the solo, but obviously the footprint would not fit in the solo's leg cavity.
Wiring and Test | Adafruit HMC5883L Breakout - Triple-Axis Magnetometer Compass Sensor | Adafruit Learning System
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The best way to bench test the compass is to install Mission Planner on a PC and connect your Solo via WiFi. Once connected, MP will provide a long line on the screen showing where the compass is pointed.
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The PX4Firmware appears to have a driver for the HMC5883L Magnetometer. The 2014 prototype magnetometer I have pictured above is for the HMC5983 which is the temperature compensated version of the 5883. I'm not sure which is in the stock solo. (sidenote: The Mro gps/compass module which they say is not directly compatible with the solo uses a the 5983.)
From my interpretation of the code, the PX4Firmware calls the magnetometer's self test mode to check for errors so i'm assuming the Solo software must do the same or at the very least does this when a calibration is performed. It also uses the results of the test to calibrate the IC and apply appropriate offsets. More info about the self test mode can be found in the datasheet.
Presumably the solo does perform a self test on the magnetometer and you could further verify that it is functioning by using the mission planner methods referenced in previous posts. You could also hook up an arduino to it and perform the self test.
Anyhow, two interesting conclusions can be drawn from all this:
1. Once there is confirmation on whether the stock solo uses the HMC5983 chip or the HMC5883 chip, it would be very cheap and easy to source a non-oem magnetometer should the need arise; the only issue would be the form factor as most of the pcb and breakout boards I've seen would not fit in the recessed area of the solo's legs.
2. If the solo uses the 5883 chip, this would offer an additional avenue to improve solo by upgrading to the 5983 chip which is temperature compensated. This might require the solo firmware to be tweaked as the 5983's register addresses may not be exactly the same as the 5883's, but a comparison of the datasheets would confirm this.
From my interpretation of the code, the PX4Firmware calls the magnetometer's self test mode to check for errors so i'm assuming the Solo software must do the same or at the very least does this when a calibration is performed. It also uses the results of the test to calibrate the IC and apply appropriate offsets. More info about the self test mode can be found in the datasheet.
Presumably the solo does perform a self test on the magnetometer and you could further verify that it is functioning by using the mission planner methods referenced in previous posts. You could also hook up an arduino to it and perform the self test.
Anyhow, two interesting conclusions can be drawn from all this:
1. Once there is confirmation on whether the stock solo uses the HMC5983 chip or the HMC5883 chip, it would be very cheap and easy to source a non-oem magnetometer should the need arise; the only issue would be the form factor as most of the pcb and breakout boards I've seen would not fit in the recessed area of the solo's legs.
2. If the solo uses the 5883 chip, this would offer an additional avenue to improve solo by upgrading to the 5983 chip which is temperature compensated. This might require the solo firmware to be tweaked as the 5983's register addresses may not be exactly the same as the 5883's, but a comparison of the datasheets would confirm this.
