LoRa Radio for 3rd party systems

[jp-drain-sol]

Tinkered with my setup some Saturday and today. I have both the Emlid LoRa radio connected and put a T in the TX line to my 3DR radio

Saturday I fought everything with it. I could get my RS2 to go fix with the LoRa for correction but not my Trimble with the 3DR.

I had some time this after noon and started troubleshooting my radio box. When connected to my computer via usb and using SNIP I could see the messages were being sent and received. Did some splicing of lines and found out my output cable to my Trimble had nothing. Replaced the TTL to RS232 adapter and it worked fine. Jotted down some notes so I know what lights should be lit etc. I had a stable fix for over an hour on both my RS2 (via LoRa) and my Trimble (via 3DR)

The LoRa radio is using 38000/902.0/18.23kb/s with messages 1006 ARP at 1Hz, 1074 GPS at 1Hz, 1084 GLONASS at 1Hz, 1008 Antenna Descriptor at 1Hz and 1033 Receiver Descriptor at 1Hz

If we can figure out how to set the config to 38000/902.0/18.23kb/s without being connected to the M2 I can route the TX from the radio to the TTL to RS232 converter and wire it to the Trimble unit.

Again, I am assuming, just like any off the shelf LoRa radio it is set via the TX line with AT commands.

Unfortunately, I will be displaying at a trade show all week. They are calling for rain all 3 days so if I get a chance I will check what voltage the LoRa receives from the M2 (3.3V is what I recall) I will power up the LoRa radio separately of the M2 but leave the RX/TX lines connected to the LoRa with the M2 TX line T’ed to a TTL converter, connect it to my laptop and monitor the communication in a terminal window.

I brought one of my Nanos and my breadboard with its power supply so that way I can power it separately.

[jp-drain-sol]

@elena.riazanova

So, external 3rd-party radios should be able to work with it to transmit or receive corrections.

External LoRa radios or a pair of matching external radios? I just want an radio that receives what the RS2 is transmitting.

I have 3DR and RFD900’s working with it but, it is a hassle, and not as clean as the internal radio on the RS2. I want to make a radio that can be powered separately and receive the RTCM from the RS2

[PotatoFarmer]

@jp-drain-sol

If we can figure out how to set the config to 38000/902.0/18.23kb/s without being connected to the M2 I can route the TX from the radio to the TTL to RS232 converter and wire it to the Trimble unit.

OK back up the truck, am I reading this right?

So the only challenge now is just to make the lora wake up with valid config without an m2?

[willstar_beleno (KAKAROT)]

[PotatoFarmer]

They need to receive a digital configuration from the m2 to work, but as simple as this is it also makes me wonder if the previous configuration is retained. 5v and ground are the wires furthest from each other btw.

[jp-drain-sol]

Not radio to radio. More like this

I will apply separate voltage to the M2, LoRa and TTL to RS232 converter with a T in the TX line of the M2 to monitor its communication with the LoRa radio via a terminal program on my laptop.

I am hoping to see what configuration data is sent to the radio to set the baud/Freq/kbs. If I can get that, I will do a script for a Arduino Nano to send that data to the radio on power up (no M2 connected, just the Nano) and see if it connects. If so, it should receive.

[PotatoFarmer]

@jp-drain-sol

Also with that configuration if you are getting corrections, you will be able to see if you can unplug the M2 and still receive corrections from the RS2. It will show if its a one time settings handshake, or if it needs to be maintained.

[jp-drain-sol]

Yep, thought of that already also. I am betting it is a one and done until the power is cycled again.

[jp-drain-sol]

BTW, during the rain, I tested the base using both radios (3DR/LoRa) and found out something interesting. I have two monitors here with me both capable of GPS and GLONASS only, a FMX/FM1000 and the newer model TMX2050. With the newer model TMX I am receiving 15 satellites (GPS/GLONASS is all it is capable of until the next generation monitor comes out). With the older model (FMX) only 8 (GPS only, no GLONASS even though it is capable). Same GPS antenna same location just changed the coax cable from one monitor to the other in less than a minute. Switched back to the TMX and had 14. Something in the older hardware is my assumption. I will have to try this on the Gen2 FMX next week.

[jp-drain-sol]

Show was cancelled today due to a downpour!

I did a little testing before I left. With everything powered separate and only the TX/RX lines connected the M2 didn’t recognize the radio.

I connected GPIO_0 and it recognized but wouldn’t let the M2 change any settings. I connected GPIO_1 and the same. Connecting GPIO_2 let it change the settings so 0 and 2 are the RX/TX so to speak. I didn’t try disconnecting 1 with the other two connected.

Next is disconnect power to the M2 and see if it still is connected and receiving. After that is monitor GPIO_0/2 and see if I can decipher the commands.

[elena.riazanova]

Hi everyone,

I see that you have an exciting conversation here! I have no idea how this should work But please share your success if you manage to do it.

@PotatoFarmer

I figured out how to convert UBX to TSIP so the “Emlid Lora Bridge” may be doable as well.

I can’t say for sure that this will work because the compatibility of Reach’s LoRa does not depend on the format in which the corrections are transmitted. LoRa from different manufacturers may be partially incompatible with each other due to the different firmware abilities. Because of proprietary firmware, they also have different configuration interfaces.

@jp-drain-sol

External LoRa radios or a pair of matching external radios? I just want an radio that receives what the RS2 is transmitting.

You won’t be able to use a 3rd-party LoRa radio with ours. You need a couple of external radios for both base and rover. But I can hardly recommend you something certain.

[PotatoFarmer]

@elena.riazanova we are aware one reach lora will only talk to another reach lora. What we are looking to do is.

RS2 Lora ———-> M2 Lora with no M2( output to 232) ————> 3rd party rover

This way you could plop down a RS2 at the corner of a field, then pop the m2 radio on the cab of your machine and use emlid lora for corrections.

Or broadcast from the m2 lora to the RS2

Emlid Lora works well but it needs a bridge out to other devices

[jp-drain-sol]

@elena.riazanova

I can’t say for sure that this will work because the compatibility of Reach’s LoRa does not depend on the format in which the corrections are transmitted.

I already know that the TX from the M2 to your LoRa radio module is normal as I put a T in the line and I am feeding both your LoRa radio and my 3DR radio from the same M2 and receiving corrections on my RS2 via the internal LoRa and my Trimble monitor via the 3DR

My above test this morning was attempting to figure out how you set the radio parameters 38000/902.0/18.23kb/s. From my initial results it is via GPIO_0 which permits the M2 to know the LoRa module is connected and then sets the parameters via GPIO_2. If I can write a script for a Nano that would set those parameters on power up, it should work as a 3rd party radio via a TTL to RS232 converter (unfortunately most Ag monitors still work in the RS232 5V standard instead of the 3V TTL.

If you want to save me some time and send me the commands rather than having to sniff them out with a TTL to USB connector and using a terminal program I would appreciate it. I would be happy to sign a NDA on anything recieved.

@PotatoFarmer

Emlid Lora works well but it needs a bridge out to other devices

This is my end goal! Using the internal radio of the RS2 to transmit to an Emlid LoRa radio that can be configured with a laptop or connected to a Nano that provides the parameters so it can be connected to any device capable of RS232 communication for input of RTCM. Once configured, at least on the current Ag monitors I am using, it will not need to be changed. When the next generation Ag monitor comes out, it may need to be changed as they are adding BEIDOU and GALILEO. The current models I am working with are only GPS and GLONASS enabled. If I up the number of messages for the other constellations I may need to change to 9.11 kb/s

[jp-drain-sol]

@jp-drain-sol

If I can get the settings from the nano, I can make a “radio” box like i did for my 3DR which is a buck converter/TTL to RS232 converter and my 3DR radio. Just replace the 3DR with an Emlid LoRa and add a Nano to control it. Would even fit in the same style box

If you look at the picture in this message, I am trying to make the same thing with one of your LoRa radio modules. There would be two things different, take out the 3DR and replace it with your LoRa module and add a Nano to set the parameters. The top left thing is a buck converter as my Ag monitor supplies 12V to the system and this steps it down to 5V to feed the 3DR and the TTL to RS232 converter power. For initial ease, I didn’t mount the DB9 connector to the outside of the Pelican box since there was room for my connector. Adding a Nano will take up this room so I will have to surface mount the converter.

[jp-drain-sol]

@elena.riazanova

Because of proprietary firmware, they also have different configuration interfaces.

This is the part I need to know, the configuration interface.

Did some testing. I didn’t see anything on the terminal program from the GPIO pins. Even if it were at the wrong baud rate, you should get garbage if it is receiving.

[rsurveyor1 (Surveyor)]

@PotatoFarmer

Or broadcast from the m2 lora to the RS2

This is somewhat similar to what I’m looking for. A M2 serving as base and a RS2 as rover, but with another LoRa device on the M2, not the one from Emlid (they are kind of expensive where I live).

Will keep an eye on your conversation with great interest.

[jp-drain-sol]

That is actually opposite of what I am trying. I really do not need the transmit part, only receive for 3rd party systems. I know they do not want to cut their own throats by enabling 3rd party transmitting via a LoRa compatible. I am not trying to “under cut” them.

Their M2 with their LoRa works fine as long as you are going Emlid to Emlid, I do it with my M2/RS2. I am trying to send Emlid RS2 RTCM via LoRa to 3rd party systems receiving corrections via LoRa.

I can do it now with 3DR or RFD900 radios but, it isn’t as clean on the RS2 with its internal radio and why have two radios on one unit if you only need one.

[jp-drain-sol]

I got some more TTL to RS232 adapters in today so I can resume my testing this weekend.

I did find this was tried previously in this thread

Reach RS and LoRa 868/915 MHz radio

I took another shot at interrogating the radio for its settings and got something back this time. *Edit: [IMG_20180716_162732] I was using ascii this whole time then in the documentation it explicitly says its hex. I used RealTerm set up the Baud rate to 9600 [lorasettings] I sent the interrogation/read command (0xFF 0x4C 0xCF 0x52 0xA1 0x52 0xF0) and got this: HEX(responce) Meaning Preamble: 24 None Model Name: 31 30 31 48 101H FW versio…

I will have to build off his work and see where I can get.

[PotatoFarmer]

good find seems this has been a long time wanted item

[jp-drain-sol]

Did some testing last evening and this morning.

Both the M2 and LoRa had their own power supply. I put a T in the M2’s TX line to a TTL to RS232 adapter which was connected to my laptop monitoring it with Realterm terminal program Hex/38400. At first all I got was garbage from the M2. I then remembered from the LM-210 design guide from Globalsat that all settings are applied at 9600 baud. I changed Realterm to 9600 and got data.

I can now see which values change the freq and Kb/s. I do not want to change the baud rate as the M2 uses 38400 I have to assume that so is the RS2.

M2 TX monitored at 9600 baud 902/18.23
FF 4C CF 55 A1 57 F1 0D C3 70 00 05 07 05 00 05 0D C3 70 05
change to 9.11
FF 4C CF 55 A1 57 F1 0D C3 70 00 04 07 05 00 05 0D C3 70 05
change to 4.56
FF 4C CF 55 A1 57 F1 0D C3 70 00 03 07 05 00 05 0D C3 70 05
change to 2.6
FF 4C CF 55 A1 57 F1 0D C3 70 00 02 07 05 00 05 0D C3 70 05

The Kb/s follows Globalsat’s standard config of 0x00 to 0x05. 0x00=0.81K, 0x01=1.46K, 0x02=2.6K, 0x03=4.56K, 0x04=9.11K and 0x05=18.23Kbps

M2 TX monitored at 9600 baud 902/18.23
FF 4C CF 55 A1 57 F1 0D C3 70 00 05 07 05 00 05 0D C3 70 05
Change freq from 902.0 to 902.1
FF 4C CF 55 A1 57 F1 0D C3 D4 00 05 07 05 00 05 0D C3 D4 05
902.1 to 902.2
FF 4C CF 55 A1 57 F1 0D C4 38 00 05 07 05 00 05 0D C4 38 05
902.3
FF 4C CF 55 A1 57 F1 0D C4 9C 00 05 07 05 00 05 0D C4 9C 05

I then set it to 915 (Globalsat default looking for 0D F6 38 from the guide)
FF 4C CF 55 A1 57 F1 0D F6 38 00 05 07 05 00 05 0D F6 38 05

Since the guide doesn’t give the different values for all the frequency settings, I will have to change to each one and learn the value of each.

My next test is to power down everything and then connect the TX line from the LoRa to the TTL to RS232 converter which will connect to my Trimble Monitor and see if the setting remain in the radio as mentioned in the other thread

@jake.harders

If they are using some version of this MOST protocol, the GlobalSat radios “remember” their previous channel settings.

If it does, then my Trimble monitor should go to fix. If so, my 3rd party radio setup should be simple without divulging any of Emlid’s proprietary data. I would put a T in the RX line of the LoRa connect it to a Nano so I can change freq/Kb/s via a USB cable and a laptop.

I am also mentioning this in the other thread in hopes, I can get DirtyHarry and jake.harders back into the conversation since they had worked on it in the past.