Old 3DR Pixhawk 2.4.5, Gimble Issues, Thoughts

Old IRIS+ owner here. The drone got pretty dusty during the pandemic and I’m just now getting back around to flying again. A LOT has changed. Rather than buying a whole new drone, I’m thinking of going a semi-DIY route and just rebuilding the IRIS+ to be more modern. I’m getting here hopefully legitimately and not just because. A couple of drivers, but the biggest one I guess has to do with the old GoPro gimble (Tarot T2D) - I’d like a better camera and maybe try out a 3 axis gimble. Plus, I cannot seem to figure out a way to make the gimble work above AC 4.0.7. I’m not sure if this is a mission control issue, an issue with the AC code - maybe just deprecating old interfaces or something, or if I’m just deficient in my general understanding. Leaning on the latter possibility.

I’m also considering how cool it would be to upgrade the pixhawk to a new(er) unit which might just be fun to figure out and better understand.

So the reason I am posting here is, this IRIS+ has all the stuff 3DR originally installed. Off the top of your head, and if you’re willing to share some links or advice, what are the things you’d likely consider - or that you see as obstacles I should consider before I proceed? I’m hoping I can keep the motors the same because I have 6 full sets of those new in the box I bought when 3DR shuttered. I also have the main body PCB boards (Assuming that’s what they are made of, it’s the structural plates internal to the drone). I also have spare legs and a few other things… so I didn’t want to start from complete scratch.

One goal would be to add Obstacle avoidance, but I am still researching how I’d want to do that. Perhaps this goal might dictate a direction on the flight controller, etc. Or maybe not?

I appreciate any insights or clues as to how I might proceed with my research.

Hey Carlton - The IRIS+ is pretty easy to upgrade. The FC is the obvious place to start
as the memory limitation in the original 2014 PX4 is restricting. I went with the Zealot H743 FC, which due to the height required slightly raising the top shell with spacers.
The original 3DR RX (D4R) was replaced with an ELRS postage stamp size RX on 915 MHz. I replaced the LEA-6 GPS with a multi-constellation device, and removed the original 3DR (SIK) radio, antenna and the coax cable. The IRIS+ is also set up for a 4S-5000-50C battery, which required the removal of much of the battery compartment foam padding. The original motors / 4n1 ESC are ok on 4S with 9.5x4.5 props - but I don’t flog it!
I’m using a TX16-S with the 915 MHz ELRS module…there is a massive amount of telemetry data available.


Hi John. I very much appreciate the feedback and ideas. I’ll read up on the Zealot H743. I have a lot to learn about how the radios work and what it means to replace all those things (new controller, etc?)

Not asking you to do all my homework for me here, just thinking into the keyboard a little bit.

One question so I understand what you’re saying better about the motors and ESC. Moving to 4S, when you say “I don’t flog it”, are you saying that you’d be careful and not abuse those motors and ESC, or are you saying you wouldn’t sell that idea to someone because it might not really work out all that well? In either case, that could lead me to stay with 3S.

“Don’t flog it” - meaning I avoid prolonged full throttle - in my case I used the original IRIS 3DR 4n1 ESC, which is rated at 25A or such. 3S - no problems.

Again, much appreciated. As part of my researching, I finally wound up reading a super important section of the documentation for AC that completely explains my issues with my servo gimble mount. The entire feature set enabling the MOUNT (MNT_TYPE, etc) configurations is not enabled on the 1-1M build I have to run due to memory limitations of the old Pixhawk v2.4.5 included with the IRIS+. So glad to have found that as it removes some of my hesitation to move forward.

I’m wondering if I could simply start with upgrading the FC by itself. One major change at a time, so to speak.

Sure thing on the upgrade. A modern FC will open some doors, such as being able to do in-flight FFT analysis, etc. Autopilot Hardware Options — Copter documentation