Newbie: Telemetry Connecting Issue

Hello, I have studied the literature but am just having an issue connecting the telemetry between my flight controller and Ground Station.

Setup: Mission Planner, SpeedyBeeF405Wing FC, Genuine SiK Telemetry Radio V2 Air/Ground, GS radio connected via usb, Onboard radio connected to FC via 6 pin JST connector, FC connected to computer via USB for power only.

Config: Serial_4_Protocol: 1, Baud: 57, Com 4(GS radio) > 57600 > Connect > Times Out.

Observations: Green lights flashing on both radios so they are not connecting. I am not using 2 of the wires in the connector (Rx/Tx 2 on FC & RTS CTS on radio), but I wouldn’t think that would change anything. I am running the FC off of usb because I do not have a battery pigtail yet, but the radio is powered under usb.

I realize that the telemetry setup is very simple so I must be missing something obvious. Thank you in advance.

Simply put: Don’t .
…as in don’t power equipment like that just from USB. Often just the flight controller can push things like the USB port on a computer close to its limits.
If you then add GPS, telemetry and whatever else you could potentially burn out your USB port in your computer.
Even if you use a USB power supply it needs to be capable of running at least 2A.

Next consideration is your power & ground connection internally. Some FC’s have the serial ports separate to power source. In that way it reduces risk of everything burning out if you had a short circuit somewhere, but this also means you have to ensure power is correctly supplied to the various items in question.
→ If in doubt checked the wiring instructions of your equipment.

Got it. I’ll solder the board up tomorrow and retest. Thank you for the heads up.

Make sure you have TX on the FC going to RX on the radio, and RX on the FC to TX on the radio.

If you aren’t using the TXRX2 and CTS/RTS paths then remove those wires from the harness, or at least disconnect one end. The photo looks like they’re all physically connected and that could be causing an issue. Not 100% sure, but it’s easy trouble shooting.

1 Like

Exactly as others said, most likely the issue is powering FC from the USB alone. You should troubleshoot that first. If that does not change anything, then we will proceed further.

1 Like

apols - im not familiar with “Genuine SiK Telemetry Radio V2”
but - they do seem unhappy with each other - assuming blinking = not connected.
on RFD900’s (similar ?)

  • netid must be the same - otherwise, the radio’s arent friends.
  • baud rates must all be the same as whatevers connecting 57600 on the modems…
  • frequencies on the radio’s must alignn (i assume)

a cool trick for troubleshooting is looping TX to RX and use a terminal emulator to see if your data goes from one end to the other and back (at the loop). Obviously once the modems have connected. This tests your TX and RX cables are set correctly - at least on the ground station.

Good luck

Did you update the firmware on the ground radio? Unlikely but if the Air radio has v1.9 firmware and the ground radio is on V2 they won’t connect.

I have not changed anything on them, bought them as a bundle a week ago. Is there an easy way to check the firmware on each?

Hello Paul, I bought just the budget mRo/3DR Telemetry radio bundle. I will try to link the website. Quick question before I get into things, regardless of if the telemetry device is communicating with the FC or not, the telemetry radios should connect when powered and give a solid green light? Mine have never done this since I bought them. Baud rate is set to 57 on the remote and I have been using 57,600 for the COM when trying to connect. Frequencies are both 915. I am not sure how to check netid though. I will look around.
Thank you for the assistance.

From the Mission Planner Sik radio page select the Com port the ground radio is on, don’t connect, and with the air radio powered select “Load settings”. However, If it’s a new radio set it’s unlikely to be a problem with the firmware version. These Mro radios should just work.

It obviously did not fill in the remote side because they are not connecting. I am not exactly sure what to look for, but it does say freq_433 and not 915 like the casing says. Can I just change the frequency to 915? Thank you Dave for the help.

Those telemetry radios come in 433 and 915Mhz. Usually you can’t change that (factory set). Some are out there where you can solder a little pin to change to the different setting.
The important thing is: Check what is legally allowed in in your country. - That’s why the choice.

Also as Allister mentioned: Remove or disconnect wires which are not needed. Sometimes those can be a problem if left in an undefined state or pulled to ground by a device not made to connect to those wires.
→ Hint: You can simply go the other way if you prefer - Mark all the wires with a tape or something and then remove all from the plug (usually a tiny screwdriver or needle works). Except the + and - wire. Check the light of the remote transmitter if it comes on.
If light is on confirming power supply then connect TX and RX wires. (no damage will occur if you mix those two up)
Check in your Groundstation (MP) if a link is being established.

Another helpful advice: Some units ship with 9600 baud setting. If you just connect receiver and start messing around with it in MP you can accidentally set one unit the the baud rate that you want, whilst the other remains in factory setting as there was no data link when you stared changing things.
→ First establish connection to remote unit, then start changing things on both sides in order for both units to have the same settings.

Interesting, so 3DR must have sent me the wrong one. I ordered the 915Mhz, the outside of the radio says 915, but the firmware clearly indicates 433. The timeline of this school project just got interesting. Thank you for everyone’s help. I’ll start sending some emails.

There’s a chance they accidentally sent one 433MHz radio and one 915MHz radio, meaning they will never connect.

In the US, 915MHz is approved for general hobby use, while you must be licensed to use the 433MHz version.

I am afraid you are correct. The GC radio is marked 433 even though it was in the 915mhz plastic. Oh well, glad we found the issue. Now I just have to get the correct one.

If you purchased directly from mRo then I’d send them a message or even call them. I’ll bet they’ll get you fixed up pretty quick.