Emlid

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Reach RS and LoRa 868/915 MHz radio


(Jake Harders) #26

Just from looking at the data sheet it sounds like that is what is going on.
Design Guide


I pulled a radio out of the reach and hooked it to a usb serial converter and was receiving the RTK data. This is a bit of good news. it means there is no handshaking required by the user to start receiving correction data. If they are using some version of this MOST protocol, the GlobalSat radios “remember” their previous channel settings. You would need to buy another Reach RS to get the radio preconfigured this way. The good news is that if you have another one laying around, you can pipe the RTCM data directly to a ublox chip and get your RTK that way.

I also tried using a HM TRP radio with the SiK firware running on it to stream data from the Emlid.
Although I was able to pick up RTK corrections there were a few issues with this approach:

  1. The web interface would not load up when the Emlid was booted up with the packet radio installed
  2. If you somehow get the web interface loaded up, and try to change ANY of the “LoRa” settings, the program hangs…forever. I am sure is waiting for a response from what was the Global Sat radio.

There is some good news however, because the Global Sat radio is sending back information about its self and the operational status of the radio, one can interrogate it to reveal the settings it is using to communicate with other Emlids.


#27

Nice detective work!

The LM-210H doesn’t appear as a current product on GlobalSat’s website. It is listed for sale on a couple of websites for under USD$20, but no stock available. I wonder if it has been superseded?

There is another MOST-link only module listed on the GlobalSat website called the LM-230H, but it does not come in a pin-header style module with the RP-SMA antenna connection, so would require a bit more work to package up into a discrete radio.

The dual mode GlobalSat radios (MOST-link and LoRaWAN) like the LM-110H1 look to be slightly different specification using an AT command set to send

Ultimately what I would like to get to is a fully Reach RS/RS+ compatible and re-configurable LoRa (MOST-link) external radio with RS232 interface.


#28

One US based website selling the LM-210H module:

Out of stock, but photo shown:
http://www.embeddedworks.net/lpwan102.html

In stock, but no photo, description looks identical:
http://www.embeddedworks.net/sens002.html


(Jake Harders) #29

After a bit more digging and with a bit of help from our friends at the FCC, we now have some more information about this GlobalSat Board.

First off, this is a lora radio so It shouldn’t surprise anyone that Semtch has a transceiver on board.

For the MCU, its hard to read from the picture but I would put my money that being a STM 8L 151G. I have not done much with ST but I do happen to have one of their programmer/debuggers in my desk.

After poking and prodding at it for a few hours I was not able to grab the firmware off of it but I am no expert. Also I am being careful not to destroy my only spare radio, so if anyone out there knows how to do this please speak up.

I will keep yall updated


(l3technologycambodia) #30

Yes, if anyone could make the radio performance better, it will be very useful either change the internal radio or Reach RS or use external radio.


(Jake Harders) #31

I took another shot at interrogating the radio for its settings and got something back this time.
*Edit:


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

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 version:	31 36 31 30 30 34 31 	1610041
    
  • LoRa MAC:	A3 6C 7D 03 00 39 00 71 
    
  • Group ID:	00 			            None (I thought this would have been the propriatary "key")
    
  • RF Freq:    0D F6 38 		       915MHz
    
  • RF Tx Rate:	05 			           18.23Kbps
    
  • RF Power:	07 			           20dBm
    
  • UART Baud Rate:	06 			       57600bps
    
  • UART Parity:	00 			        None
    
  • Wakeup Time:	05 			        1sec
    
  • End Word:	21 			            None
    

It is curious even though I set the baud rate to 9600bps the radio claims to be talking back at 57600bps.
No, I dont get anything back when I change the baud rate to 57600.
Maybe this is a change in the firmware that did not get documented in the Design Guide.

Thats it for today.


(Naratchr) #33

Reach RS use LoRa for radio only, PLS try to use LoRa config tool(Application software) from GlobalSat config it.


(Jake Harders) #34

I don’t know of any configuration software GlobalSat provides. The only way I was able to reconfigure the radio and the way that the Reach RS does it is by pulling pins 6 and 7 high, then issuing the commands that change the properties of the radio.

Here is the example given by the Design Guide:

For example, Module setting is as below:
Group ID is 0. Air rate is 0.81K bps. RF frequency is 915.000MHz. RF power is 20dBm.
UART Baud Rate is 9600bps. UART parity is none. Wakeup time is 1 sec.

Write the setting:
0xFF 0x4C 0xCF 0x52 0xA1 0x57 0xF1 0x0D 0xF6 0x38 0x00 0x00 0x07 0x03 0x00 0x05

Response:
0x24 0x31 0x30 0x31 0x4C 0x31 0x35 0x30 0x37 0x32 0x39 0x31 0x2A 0x1D 0x1C 0X1D
0x1E 0x1F 0x2A 0x2B 0x00 0x0D 0xF6 0x38 0x00 0x07 0x03 0x00 0x05 0x21

You are welcome to look up exactly what is happening here but I can confirm that this method works with with a FTDI USB to serial converter and RealTerm terminal software.

If you know of any GlobalSat configuration software please share the link


(Naratchr) #35

http://docs.inertialsense.com/user-manual/App_Usage/LoraConfig_1509181.zip
Try Baud Rate 57600bps.


#36

Can’t get the software from that link to work unfortunately. Have you got it working?

Think its supposed to look like this according to that site.


(Naratchr) #37

For Operation Mode 4(Setup mode) connect FTDI USB to serial converter to LoRa and leave pins 6(P2) & 7(P1) alone do not connect it with ground. read and write after configuration test by operation mode 1 (connect ground to pins 6 & 7).


Reach RS - LoRa specs
(Jake Harders) #38

The software provided is for the InternalSence RTK system. The only way this has a chance of working is if InternalSense and GloabalSat are using the exact same communication protocol when configuring their chips. That may be the case here but I have not gotten their software working either (missing plugin).
If a gui is really of that much, interest, I will hack something together and post it on github but I dont see any flaws configuring using hex commands.


(Francisco Cabrera) #39

Hi, Jake, could you fix the issue with the lora receiver?


(Francisco Cabrera) #40

@naratchr @DirtyHarry anyone could receive corrections using LM-210H or LM-230? I’m stating a project with RPI + LoRa TX/RX + NEO-8MT and need to receive my corrections from Emlid Reach RS+ to my RPI rover


(Jake Harders) #42

@fcabrera I ended up using an external radio and giving up on the LoRa radio inside the Reach RS+. fc6c33c376a75e6d7db75db2a231c6dc94b14f07_2_281x500

I made this just in time for the launch of the ReachRS2… not great timing


(Brent Wiebe) #43

Nice looking product though!


(Francisco Cabrera) #44

Wow that’s excellent… 3d printed? Used usb-serial to the lora modem?
Reach RS2 its compatible with all lora modules?


(Jake Harders) #45

You got it. It’s a fairly standard radio in there. Not Lora or anything. Im sure you know the one to which I am referring.
I made it to communicate with another device without having to totally reinvent the wheel. You could use it to communicate to another reach rs but that was not the motivation and I don’t know why one would want to. Lora’s range is just better.


(Andrew Yushkevich) #48

It’s not possible as Reach has its own protocol which isn’t compatible with other LoRa modules, with the exception of the module in devices.


(Jake Harders) #49

So you are saying if one could obtain an LM-210 H, if they will work with the Emlid devices?