Digi SX (PRO) / Ardusimple LR (XLR) Radio compatiblity

I don’t see why not, as long as the power amp can handle the 20mW input. I would expect you can turn down the power output of the Digi SX but I’m not certain.

Possible but if you wanted to fulfil regulations, I bet a higher power product would cost less than the lower power product combined with a high quality amplifier (both aiming at the same output power).

A high gain antenna might give a similar result. (not knowing what you are using now)

This one is available. But haven’t connected yet. I’ll do it later, when the main work in the field is over. It is possible to install at a height of 15 meters. I want to know how far the reception will be.

When you have a line of sight with this antenna, you will probably have no problem reaching the 10-14 km distance. Make sure you use ultra low-loss cable to the antenna, or mount the F9P to the antenna base. (10 dbi antenna gain could easily be wasted by cable attenuation)

@m_elias, are you still using the SX Pro with hopping firmware? What kind of antenna are you using on the base station? I’m finally reworking my base station and I put up a new antenna mast using an older antenna I had lying around, but getting really bad range. About 30% dropped messages at only 2 miles!

What’s strange is the same transmitter hardware used to control my pivots and they never had any communication problems with 1 watt over a 50’ coax to the base antenna up to 5 miles, although the base antenna for the pivot system was probably 7 dbi with little ground plane petals. The antenna I’m trying is probably also 7 dbi but just a dipole.

Something isn’t right with my cable and antenna clearly. I tried putting up a temporary antenna (same type) but with a shorter cable and it seems to work better, so maybe it’s the cable?

Anyway I’m thinking about getting a 9 dbi antenna like this one. And probably I’ll get a new cable made up. I need it to be about 30’.

I don’t think I’m using hoping firmware, I’m using the same as ArduSimple comes with (unless they’re the same). I definitely had range issues with a mismatched connector but now, with the correct connector, it’s working well even at 7 miles. My antenna is 4+ ft long and my cable is only 15’.

Can you tell me what version that firmware is? I guess it’s not in an accessible place, eh.

From what I can tell there are only two firmwares for the SX Pro, there’s the hopping (point to multipoint), and the digimesh. So I’m guessing it’s still hopping? EDIT: There are three firmwares: SX (what Ardusimple uses), Digimesh, and Hopping (compatible with old radioes).

Also what was mismatched about your connector you were using?

I’m not on the Mesh firmware. SMA with RP-SMA and no center pin.

XCTU says firmware 900A

ahh yes that would do it! I’m pretty sure I’ve got the right connector, but it’s worth checking again!

Okay many thanks! I’ll compare my version to that. I think that’s the same version as I’m using.

What serial baud rate can you push through your SX Pro with that 900A firmware?

I’m only running at 4800, so that my ethernet serial server buffers the bursts and the RF isn’t as busy.

Ahh. If I send out RTCM for GPS, Glonass, Galileo, and Beidou (overkill I know) I feel like I have to be at least 38400 baud.

I’m doing at least 3 constellations, but 1006, 1230 & 1033 are only sent every 20-30s.
But 19200 should be enough.

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Appears that the RF data rate is 250 kbs on the SX radios with the 900a firmware, so I think they should be able to take whatever baud rate you want to throw at them. But yeah I’m not doing much more than you.

I thought that XBee Pro SX modules were all the same but differed only but firmware (and antenna connection). But apparently not. I have a newish board that has the Pro SX module on it but the part number shows it is a 9Xtend-compatible board (for older applications), but XCTU will not let me flash it to SX Pro firmware. Ahh well. fortunately all my rover modules can be changed over to SX. I’m going to buy a new module for the base station and switch everything over and see if I get better coverage. I’ll also put in a new antenna as well.

Just for information purposes, 0x40 in this field means “point to multipoint mode” wherease 0xC0 means “digimesh.” So for an RTK base station, mode 40 is what we want.

Since no one online seems to have the SX Pro modules in stock, I ordered one from ArduSimple and it came promptly. I’ve now converted my base station and rovers from the 9Xtend firmware to the Digi SX firmware which is what Ardusimple LR and XLR ship and use.

Frankly these radios are disappointing me, and maybe the 9Xtend never worked as well as I thought either (I never really checked message integrity before). Basically I’m seeing about 10-20% of all RTCM messages get corrupted consistently. This is at a distance of 100 ft! I thought it was a UART overflow issue, but using Serial flow control didn’t help. I tried different baud rates to no avail. The system is workable even with the packet loss, but it’s really annoying. I cannot think of any reason for the loss.

I tried 10kbs mode, but that didn’t work at all for me at all, even though my RTCM data stream should fit in 9600 baud.

I’ve also tried API mode and tried taking the RTCM3 messages and sending them in individual radio frames, but that ends up being super slow. I takes nearly 500 ms to send the frame and get an acknowledgement that it was sent successfully.

It is nice that I can use XCTU to configure radios over the air, though.

That might be part of the problem. I was having all sorts of trouble at short range till I turned transmit all the way down.

Yes that could be part of the problem. I had issues at distances of 2 miles too, though. But maybe some packet loss isn’t critical. I’ve got a new antenna to install next week and then I’ll see. I’ll be happy if I can get 80% of my packets to the whole farm.

I was impressed with how well it worked at 7 miles away.

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