I have just bought some mobile 7 elrs drones to fly with my school club. I’m based in Petersfield and really need some help with setting up the drone, my controller and drone won’t bind. Are there any local enthusiasts who would be keen to have a go at helping me?
What radio and control system you using?
Hi @Kettch, it looks as though you’re quite new here 
Why not nip over to the Introductions page, and say hello properly and tell us a bit about yourself. 
Looks to be elrs from the original post
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Hello @GunjaFPV , I’m using ELRS Radiomaster Pocket with an ELRS Mobula 7.
Previously had the same setup on Frsky and managed to bind it after flashing an update to the drone. Also bound meteor75pro with Radiomaster Pockets, on ELRS.
I’m on a school system so difficult to install downloads quickly, everything has to be approved by admin. Trying to use beta flight configurator but keep getting a ‘Failed to find a serial port’ message after flashing the software. All help videos seem to have differing info than what I see on my screens so getting a bit confused!
I’ve managed to navigate these tricky waters before but this one has stumped me.
@SparkyFPV definitely will introduce myself!
I use binding phrases. Weird you’ve flashed betaflight and not appearing on configurator. Tbh I don’t tend to wipe and flash bind and flies and whoops as can never get the PID tune right again.
You got experience so it’s a little strange. With the pocket I guess they both on a 3.x brand of ELRS. Is it serial or SPI ELRS on that quad?
Yeah silly me not reading. Assume mobllite 7. But with loads of these things loads of versions and freaky and ELRS and HDZero and analogue and walksnail… Probably all different FCs…
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Might have flashed the wrong firmware if there so many versions
Try going back to the dump file - Mobula7 1S and Mobula7 HD 1S manual documents and dump file – Happymodel
Then for ELRS. Power the drone on - but not your remote control - look for new wifi network on your phone ExpressLRS RX
See - Wifi Updating - ExpressLRS [Updating on Phones (click/tap to expand)] or watch https://www.youtube.com/watch?v=J3Hg2f7RL1A
Also - maybe use the FPV APP You Should Have (iOS/Android Mobile) - Oscar Liang ?
School computer not necessary.
This is really useful, I’ll try all these things tomorrow and let you know. I’d forgotten about updating ELRS via WiFi - I did all my binding around this time last year and haven’t had to do any since, until we got new drones in this term.
@GunjaFPV I have some experience but not as well versed as you, some of that went over my head! I’ll do some research on what you said and figure it out.
@bmsleight I actually used speedybee app for a lot of previous bindings and found it super easy, but on this occasion I plug my otg cable in and the app just quits without warning. I’ve bought a proper data cable online so will see if that is my issue.
Lots to try out, but as ever, lots to learn as well! I’m approaching it as I need to get both controller and FC onto the same firmware. Maybe the controller software isn’t updated either, but I can’t view what firmware it’s on as the menu doesn’t have the v2.3.0 number for example, even on the Version tab of edge tx.
How do you know what the right firmware is for your drone?
Which model drone is it ?
Betaflight - Search for the dump file with same betaflight version.
The ELRS firmware - as far as I recall are really tolerant on version numbers.
Depends on the flight controller tbh. Best looking at that and hope you took a dump before flashing. I always do a dump all before doing anything on any drones and in the comments at the top of that will be what the current firmware and hardware is. If you flashed it then might not be right.
Finding photos of the exact FC best bet then. Be a happy model something or other I guess
Yes, in a manner, you need to have the same base version in both TX and RX but sub versions are less critical.
I didn’t take a dump of the FC before flashing. However, I never actually flashed the firmware because of the failed serial port error. I think that either my school computer was blocking the connection or the cable wasn’t a true data cable. Therefore I think I can still dump as the drone was never flashed.
Ahh okies, just the connection.
Yeah make sure you have a decent USB cable, hate that they not all created equal! But before messing about, do take a dump of the config. I tend to do it when new (just make sure it flies before messing with anything), and then take a dump once I’ve setup the things I wanna (rates, receiver, OSD, etc, etc)
Irrelevant these days, which is nice, esp. when some of these whoops come with SPI RX’s which you can’t update (easily), as ELRS don’t officially support SPI anymore! Shame that new HDZero AIO is SPI, but get they could just not squeeze another ESP and other ICs on there. Impressive job… I want one, lol
Just a few other considerations in addition to advice above:
- Has the machine you’re using connected to the drones before or could it be missing ImpulseRC driver fixes
- If flashing BF, the target for the X12 ELRS Mobula 7, according to UMT is
CRAZYBEEF4SX1280 - These boards have an ELRS SPI receiver I believe, so you can’t flash BF to to 4.5, and I don’t think you can have ELRS v3.0 or later
That last point is really important (in addition to making sure radio & receiver are on similar major versions). However, given the clever people above didn’t mention it I’m probably either completely wrong, or wrong on exactly which versions stopped supporting SPI receivers, so worth researching.
Hope that helps.
Ok so here’s the update - still stuck!
I started with plugging the battery into mob7 to set up the ELRS via WiFi. No WiFi turns up when plugged in. I scrapped this idea.
Went to beta flight to save my settings on the drone, and whilst saving the settings I looked up to the top of the file and found the following
This suggests that the mob7 is on beta flight 4.4.2, which I thought has ELRS 3.0.
My radio is also on 3.3.0, as I managed to figure out where to find the version number. So they should connect…
Whilst viewing another video I noticed that on the ELRS documentation listed here SPI Receivers - ExpressLRS
They suggested that the SPI receiver does not work with F1000, which is what my RC was set to.
So I went to beta flight, clicked bind receiver, changed the packet rate to 500hz, and bingo I have telemetry and can change RC settings in betaflight.
However, when I unplug from betaflight, the controller is still connected, but nothing happens… None of the switches that worked whilst drone and RC were connected to betaflight work. I get telemetry gained messages, and that is it.
Betaflight MUST support ELRS 3.x, as I have an SPI RX on the Mob6 ECO. And indeed in the link it states the following:
SPI receiver compatibility with ExpressLRS v3.x requires your flight controller be flashed with Betaflight 4.4.0 or newer. If you are running Betaflight 4.3.0 or Betaflight 4.3.1, your receiver will only work with ExpressLRS v2.x. Please update to Betaflight 4.4 or newer for ExpressLRS v3.x compatibility.
I assume that means you CAN have 4.5 (not that I’ve upgraded that or tried yet), but my 4.4.2 works fine as yours “should”. I think my Radio is 3.3 or 3.4 (not checked)
What happens when you power from a battery do you get the link/telemetry resumed?