If you are having trouble getting into the CLI of openlrsng or openlrsng (gitsly) on FW 2.7.3 make sure that your TX is in bind mode, hold down the failsafe button and power on then when you hear the beep let go, you should then hear fast beeps. Connect using putty and an FTDI adapter using the correct com port and try 57600 first, when you hit connect you should see a black screen, hit enter and you should see the menu. If this doesn’t work try 19200 followed by 115200 and then the rest.
So you want to be able to see the OrangeRX RSSI?
The way i did it was by building a buffer circuit and feed that into A0 on the APM. MinimOSD picks up the RX RSSI through the mavlink messages (tuning required).
Build this circuit:
I read in a few places that you need a time constant of greater than 27ms, using this tool you should be able to find a combination that works for you.
Once you have build the filter connect it up between the RSSI S pin on the RX, ground and the A0 pin on the APM. If you have done it right there should be no smoke.
Hook up the APM to mission planer and navigate to Config /Tuning Standard Params and Change Receiver RSSI Sensing Pin to A0, write parameters and disconnect.
You should now have working RX analog RSSI on the APM and MinimOSD, which will need to be tuned for you min and max.
Original Post by Neil Fitch at diydrones here
If you are like me and have ditched the 3DR radios in favor of the OrangeRX OpenLRS hardware then you will need to modify the APM settings in order to make this work.
The default baud rate for the APM when using the 3DR radios in 57600bps but that is too fast for the OpenLRS setup. I have configured mine to be 19200bps but haven’t had much time to test it yet, it seems to work well though.
First things first, i tried to use the openlrsng firmware by kh4 here but it didn’t work very well with Mavlink so i did some googling and found this by Martin and i must say it works well. Kh4 has said that he is re-writing some of the code and will eventually merge it into his branch. There is also a Mavlink bug fix listed here for his version.
So with Martin’s openlrsng installed on my APM 2.5 board we need to change some settings to be able to connect to the APM through the OrangeRX hardware:
With the APM connected to your computer fire up mission planner and navigate to Config / Tuning > Full Parameter List.
Set SERIAL1_BAUD to 19 which is 19200bps
set SR0_PARAMS to 5
set SR0_EXT_STAT to 2
set SR0_POSITION to 1
set SR0_EXTRA_1 to 1
set SR0_EXTRA_2 to 1
set SR0_EXTRA_3 to 1
At this point MinimOSD will be able to receive telemetry with the lower baudrate (Once you flash it with my firmware here)
When you’ve set those, press Write Params then change to the Config / Tuning > Standard Params and change Telemetry Baud Rate to: 19200
Write the parameters and disconnect mission planner and physically disconnect your USB connection to the APM.
at this point you will be able to connect to the PAM using Mission Planner through the OrangeRX hardware.
Original work: minimosd-extra https://code.google.com/p/minimosd-extra/
As i couldn’t find a recent copy of MinimOSD-Extra-Copter i synced the source and made the changes to allow the MinimOSD to receive Mavlink messages at a reduced speed of 19200bps down from 57000bps as i am using the OrangeRX OpenLRS modules to transmit telemetry data rather than the 3DR radios.
I have included the file for download, you will still need the Tool and the Charset file. The links for those are below.
Arucopter r726+ build with 19200bps rate set: ArduCAM_OSD_Copter.cpp
CT Tool: CT Tool