I am running into issues operating the new 2021 version MRO GPS cards running the IST8308 compass.
My configuration is to operate dual GPS units. Build details below.
Pixhawk 2.1 Orange Cube (or Black Cube) with ADSB Carrier Board
Dual MRO UBLOX M8N (or M9N) GPS cards
Mission Planner (Latest Version)
When I attach two of the 2021 version GPS cards from MRO I can only see one compass.
My work around for the issue is to install a 2021 version GPS with the IST8308 compass and also install a 2019-2020 version of the same GPS card which uses the IST8310 compass. Only in this configuration will Arducopter recognize both compass’s at the same time.
I have confirmed that this is an issue with the Orange and the Black cube.
I have the same issue with the MRO Location One compass. I can only recognize a single compass when running dual GPS units although it seems to work with the Black Cube and not the Orange Cube.
Would appreciate any help and can supply more information at your request.
Good day, if i remember well you cannot use all the mags when you are using two gps modules with mags… only three mags are recognized by the firmware… if you are using also the second gps module with mags only gps will be use
Thank you for replying David.
I understand that only one mag is used at a time. They do not blend like gps.
I utilize two tower mounted GPS units with mags, for redundancy. In the past with the 2019-2020 versions of the MRO compass/gps card, arducopter recognized the mags from the multiple cards. With the latest update I am only recognizing one of the mags and not both.
Am I the only fellow running dual MRO cards with pixhawk2.1? I figured this problem would be widespread.
do you mind attach a pic of the hardware id from MP.
I think you don’t need add one more module with compasses for provide redundancy.
If you have the mRo LocationOne i guess its enough for the application you need. Rm3100 is a good magneto and provide an high resolution with low interferences.
Also the others mro gps modules are good but are designed for different applications… ive three mro gps modules and two LocationOne and they run well… for now i don’t think to add a second module for blend…
Thank you for your input. I require redundancy for my design. These drones are used heavily and I have had GPS card failures in the past. Could be a wire in flight or a bird strike that takes out an antenna. I cannot risk a single GPS/mag UAS.
Below are some photos of the dual GPS MRO setup with a “2019-2020” 8310 (dual compass) and a “2021” 8308 GPS unit installed. I have attached screenshots of the hardware and the compass page.
Below is with dual “2021” MRO M8N 8308 GPS units. You can see that only one of the cards is recognized. The other is shown as unknown.
Why do you all think this has changed? With the old IST8310 compass units both would be recognized…I think. The old units “2019-2020” chipz also had dual compasses on each - the ( IST8310 or an Honeywell - HMC5983 or a **QMC5883) and a LIS3MDL. Perhaps I was seeing a LIS3MDL on one and the IST8310/HMX593/QMC5883 on the other? I never paid much attention past the calibration in regards to bus# or device ID. The compass page has changed in Mission Planner in the past 6-12 months to show different compass info and priority order.
Incidentally, I do have another crumb.
Below is a screenshot of a 4.0.7 black cube with a dual GPS cards installed (GPS 1 and GPS 2 ports). The 2021 MRO “ultra redundant” M9N GPS card is used which incorporates a dual compass composing of a LIS3MDL and IST8308 on each chip. The 8308 and LIS3DML are the only chips currently used on the card. Two cards installed on the drone looks like below.
Well, as i can see the fc recognized 3 compasses and its correct coz firmware cannot find more than 3.
it’s important keep the gps module far from antennas and fpv antennas… usually if you have too high offset after compass calibration usually we change the position of the module.
On mro module after Honeywell retire the HMC5983 they replaced it with the lis3mdl adding also the ist8310.
With the new upgrade they have change the magneto… im doing some test with the mRo m9n with dual and i don’t have any regrets.
For your case i can suggest you to add the kitcan node and place it inside your frame… the kitcan node is a CAN BUS module with the rm3100 compass… and use the second gps module as blend.