I was thinking of soldering the radio to the intermediate board and it would become a throw away if it got damaged. How about soldering pin headers to the radio instead? Is it an uncommon pitch?
It’s 1mm pitch. But I’m not sure the three sides line up perfectly on the 1mm square pitch.
Really, though you only need 4 connections. Gnd, Vcc, TX, RX. They are all together on the left side, near the antenna side of the board.
I’m thinking to securely mount them they need soldering to a board with its own mounting holes.
Any idea why they are called “XBee Modules”? They don’t match the XBee footprint at all.
Edit The normal XBee footprint is called XBee TH (or THT) and the Digi SX radios use XBee SMT.
I have the mid-range radio from digi.com and it sits directly on top of the SimpleRTK2B board xbee connector.
Here’s the full manual for the XBee SX RF modules.
See page 21-24 for the pin map. It looks like if you ignore pin 1 and start with pin 2 on the SX as pin 1 on the standard/popular xbee pinout (like on the arduSimple boards), then VCC, Rx, tx, and pin 11->10 gnd should line up. Even pin 5 reset & pin 6 rssi output should match.
So I’m thinking it should work to solder a 2mm pin header to the SX and plug it into any standard XBee socket.
Just a hint for those from Europe: Buy modules in the 868MHz range (instead of 915MHz) for legal reasons with the appropriate antenna. I didn’t look for details, but normally all manufacturers have these two variants of the same product.
Seems mine was actually the long range product (not the longest range “extra long range” product).
But I bought it via Ardusimple and I see now that they must have added the connector board:
Yes the Ardusimple long rangle radios seem to be using the Digi SX modules, probably using the 9Xtend hopping firmware (mesh doesn’t make sense for this application).
For my purposes I’m not a fan of the SMA antenna jack they are using. I’d rather use an SMA pigtail and put the SMA jack on the enclosure itself. I’ve had bad luck with SMA extension pigtails. They tended to be slightly out of spec and the center pin would push in, shorting out the pigtail.
And the Extra Long Range radios are the SX Pro? The Long Range & Extra Long Range radios appear interchangable except that not all boards with the XBee socket can support the Pro’s higher power consumption when transmitting but as @torriem mentioned earlier, the rover doesn’t need the high power radios because it only needs to receive.
That appears to be correct, yes. I wonder if ardusimple would preprogram them to whatever packet preamble and hopping channel you want in case there are other radios in the area that might conflict.
Can I add the size of each packet from the ublox packet console to calculate the air data rate in the radio ? I am trying to get the maximum range out of these rfd900x radios. I have the baud set at 460k to match uart2 in the dual setup.
But isn’t 1 Hz enough for the ntrip signal, to achieve rtk fix, even in dual setup? So baud rate could probably be quite low I guess.
This one with the spring connectors? GitHub - faludi/xbee-smt-socket-tht-adapter: XBee SMT Socket -> THT Adapter
or this one without the springs? GitHub - faludi/xbee-smt-tht-adapter: XBee SMT -> THT Adapter, including XBee PRO SX
Here’s some info from Digi regarding how the pin mapping and layouts compare.
https://www.digi.com/resources/documentation/Digidocs/90001506/Default.htm#containers/cont_migrate_th_smt.htm
Sounds like XBee TH (or THT) is the standard form factor and XBee SMT is the SX radio style.
Edit:
Boards for purchase
Yes. 1Hz is plenty. Some messages can even be 0.1Hz. I’m only using the following messages: 1005(0.1hz), 1008(0.1hz), 1077(1hz), 1087(1hz), 1097(1hz), 1230(0.1hz) and 57600 baud. I think I could use 38400 probably. If you turn on more messages you might need more bandwidth of course.
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Yes I looked at the board with spring clips. Unfortunately the clip things are hard to find and expensive. And for reliability soldering to the board and using the XBee-style headers would be more reliable. I was just thinking if I kept the little module clean it could be placed into my Digi programmer board if I needed to tweak a setting like the baud rate.
However I could just as well do it with some kind of Xbee to serial USB adapter though, if I used a module soldered to an adapter board.
Yes, I have run rtcm3 messages (group 7) at 38k baud 1hz with a single rover, and it worked well, but with the dual, I believe that the MB receiver is also calculating heading and roll with the rover receiver on the same uart2. I ran it at 115k and it seemed okay, but was concerned about that low of a baud since Mattias stated to run at 460k. I’m not sure how to test what is needed short of trial and error. I know that high of baud is shortening my radio distance, but thought if I can reduce air speed, I might extend it some ???
Lower air speed should improve receiver sensitivity and should help with range.
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It’s on 64kbps now. I wonder how low I can go. It just needs to be higher than the packet size, right ? I was planning to add the size of each message in the packet and set it just above that.
Edit
I tried to lower the air rate to 57 and it didn’t work correctly. Put it back to 64 and went ahead and lowered the baud in the radios and GPS to 230k. Works well with no loss of rtk. Will test distance when I can.
Everything is working well except I still have the offset when going north and south, and the HDOP in AOG is all over from 5 to 29. I mean the number next to 10Hz that is just above rtk fix. Checked both GPS modules and HDOP is .5 to .6 always.
Top picture headed north on turn rows. 20 ft drill in correct position to previous pass which was sown headed south. Still east and west are fine ???
The other picture just showing HDOP. Took 5 pictures back to back and had 10 to 16 in a couple seconds. I put stainless steel ground planes on my antenna bar, with ublox antennas attached with screws. Went ahead and put a thin circle of carbon steel under them, thinking it was a ground plane problem, but no change.
Could use some suggestions with this as well
Thanks