Extremely long post warning! It turned out much longer than I intended.

Some more details on this new version of the Tunnel Rat. The main reason I want servo tilt on it is so I can use it for poking around in old abandoned mines. This is a video clip from one specific trip where I would have greatly benefited from a drone. This was the third shaft I rigged, the first and second quickly turned into dead ends. If I could have sent down a drone I would have saved two days of rigging, abseiling and climbing back out, and I'd have saved on gas money because I had to come back and it's a bit of a drive.



At the video end you can see it opens up a bit. This is what it opens up to:



I'm at about 150 meters below surface and standing on top of a cliff, not sure how far it drops but I'm guessing the water level is at about 350 meters depth. Of coarse I want to continue exploring but the rigging to get down is going to be extremely laborsome so I want to poke around with a quad that has camera tilt and lights. After rigging for hours and abseiling down only to find out you missed a landing with 5 meters is pretty frustrating. That's where Tunnel Rat will pull it's weight.

I originally bought a DJI Mavic for this purpose but I've hated flying those things right from the start. Without GPS underground they go into ATTI mode and become really difficult to fly in tight underground spaces. I tried with the Mavic and was lucky I got away with only broken props! Now I only keep it in case I have to retrieve a quad stuck on a roof or similar.

I've played around with servos with the intention of building camera tilt but I didn't have any good ideas on how to do it until I saw LiPoFly's post on camera tilt which inspired me to get back at it: https://intofpv.com/t-next-project-walks...#pid197074

On to Tunnel Rat IV: For those interested, sorry I didn't take any pics of the assembly. I really didn't think it would be much to take pictures of, there is a 20x20 stack with a naked DJI Air Unit on top. I just moved over the stuff from previous beaten up frame and soldered on some wires with connectors to the FC:



The small one to the left is the USB connector (more on that later). The larger one with thicker wires for the servo with 5V, GND and PWM signal. The small one on the right is for the LED driver circuite with 5V, GND and two PINIOs with on/off signals. The larger one to the right is BAT+ and BAT- for powering the LEDs.

The CT30 frame can not support a downward titling camera in it's original position with the stock parts. So, before I started with 3D printing I built a small camera mount out of scraps from the old frame and used the original CT30 top plate. It looked a bit like this (I didn't bother with properly mounting it for this staged photo):



The vibrations in the camera with this mount where nasty so I had to scrap it. Also I had difficulties keeping the servo still, the plate it was on would move around and I couldn't figure out a good solution to keep it still without permanently gluing it to the frame. I had been putting off getting a 3D printer due to the steep learning curve but now I felt I could no longer avoid it so I sucked it up, got a second hand printer, downloaded Fusion 360 and watched a few youtube videos. Low and behold, I managed to design a top plate with extended camera arms and a slot for the servo to slide into, keeping it from moving around but still having it easy to replace. Because of the troubles I had with a reliable way to attach the movement wire to the camera I designed a small case for the Caddx Polar.





It works very well, the top plate utilizes the CT30 action camera soft mounts, camera is able to tilt down and is a extended out so I actually see something besides the frame when titling down.



I have utilized some parts from the previous frame. I hacked up TPU mount for the Crossfire antenna and used it here. This was before I started 3D printing. It's ugly as crap but hey, a small part of the Veyron frame lives on!



One thing I really liked about the Veyron frame was the solution for the USB connector. It is definitely something I am keeping because otherwise I would have to tear this thing apart just to get to the USB port on the FC. For now the connector cable position is temporary, I'll come up with a more perment solution for the actual USB connector. As it is now I just leave the USB C side on the USB cable and use the wire connector to connect/disconnect with Betaflight.



I've made all the wires with connectors fairly long so I can move stuff around a bit without having to take the frame apart. For now all cable positions are temporary, I'll have to make more permanent positions for them but I'd say this thing is still under development so now I like the flexibility.



The Betaflight setup was fairly straight forward. JB's video linked a couple of posts above was a massive help. His video is for BF4.3 and I've installed 4.4 so I had to include some options in the cloud build of BF. I had to include Servos and also the LED Strip options or else I was unable to free the LED_Strip resource for servo usage. First time I flashed I couldn't do anything with the LED_Strip, you have to have included it in the cloud build or you can't use the resource for something like a servo. Also the Servo tilt option must be enabled in the Configuration tab of Betaflight. Channel forwarding is supposed to work if you don't do this but this enabling servo tilt works fine for me so I haven't bothered with any channel forwarding.

Here are resources and commands I used for re-assigning LED_Strip output to servo control. First I found out what the LED_Strip resource is, then I free the LED_Strip resource and then assign the servo to it.


Then in the receiver tab I need to find out which of the AUX channels my slider on the radio is assigned to (in my case AUX 8), then set the corresponding channel (A8) in the servos tab.

The commands I used to re-assign SERIAL_RX 5 and SERIAL_TX 5 pads to PINIOs are:


Then in the modes tab I assign an AUX switch to modes USER1 and USER2.

That's it for now... a lot more written than I intended... did anyone actually make it this far? It's late and during the night someone (something?) usually logs on to my computer and screws up my posts, messing up spelling, grammar and so on... When I read in the morning there all these spelling and grammar issues that I swear where not there before so I usually end up editing the crap out of posts like this many many times in order to fix what whoever/whatever did to my post! Sorry in advance for that...

I made it to the end, and it was damn interesting.
Thanks for taking the time to write it up.

Breathtaking photo!! Voyaging into a different world... interesting use of drones to go down instead of up.
Did your Mavic have the obstacle avoidance sensors, I think the newer DJI camera drones are relatively stable these days even without GPS lock, but not sure how they'd do with no floor in sight. It looks really dark down there, are you planning to attach some LED headlights or using a low light camera (I guess polar if you are using DJI)? Looking forward to seeing exploratory flight footage. It would be really nice if you could tether your quad with some safety line...

(21-Jun-2023, 01:30 AM)mstc Wrote: Breathtaking photo!! Voyaging into a different world... interesting use of drones to go down instead of up.
Did your Mavic have the obstacle avoidance sensors, I think the newer DJI camera drones are relatively stable these days even without GPS lock, but not sure how they'd do with no floor in sight. It looks really dark down there, are you planning to attach some LED headlights or using a low light camera (I guess polar if you are using DJI)? Looking forward to seeing exploratory flight footage. It would be really nice if you could tether your quad with some safety line...

The Mavic 2 does have obstacle avoidance but I think only forward which didn't help in the mine I was testing it in. The ATTI mode on it makes steering strange and there is a significant delay in reactions to stick inputs. Anyhow, these Mavics are no fun at all to fly. My interest in FPV qauds was never only for mines, it's just another way to use them.

I have the Polar camera on and I will be installing LEDs. A few posts up I was testing some different LED combinations. However, those LEDs where fixed, now I want to add them to the camera case so they always are following the camera tilt. I just hope the servo can handle the added weight, it's something I will be testing soon enough.

Nice theme, beautiful photos and videos.
I'm waiting for a Walksnail HD Pro Starvis camera from Aliexpress store to make a 2.5" night baby FoxWhoop25. Has anyone used infrared LEDs to light up at night?

(21-Jun-2023, 11:08 AM)LiPoFly Wrote: Has anyone used infrared LEDs to light up at night?

I haven't myself, so far I'd like to try and keep "standard lighting" for video footage purposes because IR looks pretty bad, but I have seen this video:

Lipofly-

Ronin was messing around with ir lighting for a while in the thread below. Ph2t also has an led thread around here somewhere, but I can’t remember if he ever used ir.
https://intofpv.com/t-ir-sensitive-night...ght=Ir+led

I want to thank the respected "Mike C" for creating a very interesting forum thread about tunnel rats :-)
I also want to thank all forum participants for their ideas and suggestions.

I am currently building a quadcopter based on FoxWhoop25 for twilight and night flights. VTX Walksnail Avatar 1S (~29Gb !!!), HD Pro Starvis camera, two 1 watt white LEDs.

I will make three functions:
1) tilt the camera from the remote,
2) turn the VTX on and off from the remote so that the VTX does not overheat,
3) turn the white LEDs on and off from the remote.
I ran into a problem, I couldn't get three PWM outputs in Betaflight 4.4.2 (SERVO tab). I could only get two PWM outputs, the third PWM output was silent. This is probably a Betaflight problem. I had to remove the ELRS receiver and put in a tbs crossfire nano rx receiver.
In the tbs crossfire nano rx receiver I can get as many as 4 PWM outputs to drive my 3 functions.
Now I'm thinking about what angle lens to put on the LEDs: 15 degrees, 30 degrees, 60 degrees, 90 degrees...
I also think if I need to put a third LED on the camera so that the light tilts along with the camera..

That sounds like a very neat project. For the servo you need PWM, but to turn things on/off you can use PINIO. I believe PWM requires the MCU's internal timers, and those are limited and must be shared by certain pins, however PINIO does not. If you are using a pit switch, mosfet switch, or BEC with an enable pin, then PINIO should work fine for both VTX and LED. I believe BF limits you to 4 PINIOs but that should be enough in your case.
Also is that a 6g servo? I think they have 2g servos too, probably not enough torque for direct drive, but maybe with a reduction gear/arm it would still work and save you some weight.

Servo 3.7g



I used two PWM switches (VTX and LEDs) and one Servo Tilt. I have defined resources in Betaflight: Servo 1; Servo 2; Servo 3. Only Servo 1 and Servo 2 could work at the same time. Servo 3 refused to work. I wasted no time and just installed tbs crossfire nano rx. Perhaps I will study the topic with PINIO again.

Many RC switches use PWM, but that is quite inefficient for drones. Your FC has to convert a simple on/off to PWM signal, send to the switch, then the switch has to translate the PWM signal back to a simple on/off. With pinio, you basically cut out the PWM which is not necessary for an on/off signal, just a straight forward on (high) and off (low).

The most compact solution is a single mosfet, Momobrut posted his design in the Scythe HD thread, its basically two smd components and fits on a wire so takes up nearly no space at all. You do need to use the buzzer pin for that solution though. Otherwise if you are already using an external BEC for your LED or VTX, then just change to one with an enable pin and no need for a separate switch at all.

Basically finished the assembly of FoxWhoop25 (Night Edition), decided to use two LEDs without tilt, lighting angle 60 degrees. It remains to set up the quadcopter well and fly it at dusk and in the dark.

WOW!!! I am speechless.

Some photos of Foxwhoop25 (Night Edition) with Walksnail Avatar HD Pro Starvis camera tilt and two 1 watt white light LEDs, weight without battery 168 grams. Hover Current (VTX and LEDs off): 5 amps. Batteries GNB 4S HV 720-850-1100mAh. :

Hi LiPoFly,

One of the best looking light set ups that I have seen.   

Also, I really like the camera tilt mechanism. 

Good Job.    iFly