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USB Controller(s) to PPM (TX trainer port)

LitterBug

Troll Spammer
#1
I have been thinking for several years about making a simple circuit/microcontroller to take the output from almost ANY USB controller(s) and mapping it to a PPM output that could be fed into a TX for controlling RC vehicles. Well, the technology available today makes this extremely feasible and very affordable. I've been playing with a variety of Arduino boards lately, one being the Teensy 4.1. One of the example programs is able to read several USB controllers and dump the output to a serial port. So I wired up a USB connector, plugged an old MS joystic in, and low and behold, it could read the Roll, pitch, yaw, throttle, Hat switch, and all the buttons. The principle is very similar to mapping a head tracking headset to a pan/tilt mechanism for FPV.

Screenshot from 2020-11-19 23-07-25.png


There is already a PPM library available for arduino so it should be just a matter of scaling the 0-255 values to 1000-2000ms, mapping the channels I want to a PPM output, plugging it into my Taranis, and mapping those inputs to the appropriate TX outputs. The reality is, you could drive a car/truck with a steering wheel and pedals, Fly a plane with a yolk, pedals, and throttle, use a gamepad, and just about any other combo you want.

Current shopping list:
Teensy 4.0 (the brain that does the remapping)​
USB Hub (if you want to use more than one controller)​
3.5mm mono cable (to connect to the TX)​
2A 5V UBEC to power it from a lipo.​

The Teensy 4.0 is about half the size of the 4.1, and I will get one without the header pins. This will keep the size extra small. This controller is VERY much overkill for the process at hand, but it is so cheap, I'm sure I can find other things for it to do in it's free time. Maybe even take the Telemetry data and put up a glass cockpit! :)

Expect more soon.....
 
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PsyBorg

Wake up! Time to fly!
#2
Well if it REALLY needs to eat up clock cycles and wants more to do set up an oled screen and make a HUD for flying or for land and sea craft too. Having a speedo and tack for an RC car driving FPV would be awesome. That way you could run it thru a prism and have it post to your glass screen like real HUDS.
 

Matthewdupreez

Well-known member
#3
I have been thinking for several years about making a simple circuit/microcontroller to take the output from almost ANY USB controller(s) and mapping it to a PPM output that could be fed into a TX for controlling RC vehicles. Well, the technology available today makes this extremely feasible and very affordable. I've been playing with a variety of Arduino boards lately, one being the Teensy 4.1. One of the example programs is able to read several USB controllers and dump the output to a serial port. So I wired up a USB connector, plugged an old MS joystic in, and low and behold, it could read the Roll, pitch, yaw, throttle, Hat switch, and all the buttons. The principle is very similar to mapping a head tracking headset to a pan/tilt mechanism for FPV.

View attachment 183711

There is already a PPM library available for arduino so it should be just a matter of scaling the 0-255 values to 1000-2000ms, mapping the channels I want to a PPM output, plugging it into my Taranis, and mapping those inputs to the appropriate TX outputs. The reality is, you could drive a car/truck with a steering wheel and pedals, Fly a plane with a yolk, pedals, and throttle, use a gamepad, and just about any other combo you want.

Current shopping list:
Teensy 4.0 (the brain that does the remapping)​
USB Hub (if you want to use more than one controller)​
3.5mm mono cable (to connect to the TX)​
2A 5V UBEC to power it from a lipo.​

The Teensy 4.0 is about half the size of the 4.1, and I will get one without the header pins. This will keep the size extra small. This controller is VERY much overkill for the process at hand, but it is so cheap, I'm sure I can find other things for it to do in it's free time. Maybe even take the Telemetry data and put up a glass cockpit! :)

Expect more soon.....
hurray another arduino programmer here. :p:cool:
 

LitterBug

Troll Spammer
#4
Well if it REALLY needs to eat up clock cycles and wants more to do set up an oled screen and make a HUD for flying or for land and sea craft too. Having a speedo and tack for an RC car driving FPV would be awesome. That way you could run it thru a prism and have it post to your glass screen like real HUDS.
@PsyBorg , I am planning on hooking up an OLED display, but more for configuration using a 4 way switch. Maybe also to display the 8 PWM values being thrown in to the PPM stream. Initially will just be a dumb passthrough for proof of concept.
OLED displays are pretty tiny. Would be better served to use a TFT panel unless we used a separate OLED for each guage.

@Matthewdupreez , I have always been more of a hardware guy than a programmer, so more of a Arduino Hacker/debugger than a true programmer.

Can do a lot of testing with RealFlight and other RC sims.
 
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LitterBug

Troll Spammer
#5
Picked up a Teensy 4.0, a couple OLED displays on clearance for $5 buh each, a tiny USB hub. Doing some breadboarding and testing, you can see here how much smaller the Teensy 4.0 is compared to the 4.1. (4.0 is on the bottom) Also can see one of the Cheap OLED displays being tested. Glad you can scan the I2C bus for the address, because the address that was silkscreened on the board was wrong. LOL
Screenshot from 2020-11-20 13-26-42.png


Here's the planned gear for the field build. Trying to keep it as small and compact as possible and found a tiny 4 port USB hub to fit the build. I'll take the pluggable connector off the OLED for the build, and 3D print a case for it all to fit neatly into. Will solder the 4 port USB hub directly to the Teensy 4.0 to save space and cabling. Still trying to decide if I want to use a 3.5mm jack, or just run the PPM cable directly to the board. For durability purposes, I like the idea of running a Jack, so if things get tugged, they pull apart instead of ripping cables....
Screenshot from 2020-11-20 13-27-08.png


Cheers!
LitterBug
 
#6
I've played a little bit more with this, aquired some hardware, and looked at a few other controllers. My plan is to go forward with the the Teensy 4.0, even though it is MASSIVELY over powered for the task at hand. Price to capability can't be beat at $20. AND there will be a black Friday sale on the Teensy Web site which should really drive the price down. https://forum.pjrc.com/threads/64717-Black-Friday-2020-Sale

Been a rough week physically this week. Started PT on my neck for Moderate to extreme Stenosis, so my head has been all over the place this week. (pinched nerves between your brain and body mess with your WHOLE body) Hope to get to a point where I can at least throw my beta together and cobble together the EZPZ firmware soon. Thinkin' this might be a good parallel build/test for Borg if he has a good USB setup he would like to try flying with!

Cheers!
LitterBug
 

PsyBorg

Wake up! Time to fly!
#7
I've played a little bit more with this, aquired some hardware, and looked at a few other controllers. My plan is to go forward with the the Teensy 4.0, even though it is MASSIVELY over powered for the task at hand. Price to capability can't be beat at $20. AND there will be a black Friday sale on the Teensy Web site which should really drive the price down. https://forum.pjrc.com/threads/64717-Black-Friday-2020-Sale

Been a rough week physically this week. Started PT on my neck for Moderate to extreme Stenosis, so my head has been all over the place this week. (pinched nerves between your brain and body mess with your WHOLE body) Hope to get to a point where I can at least throw my beta together and cobble together the EZPZ firmware soon. Thinkin' this might be a good parallel build/test for Borg if he has a good USB setup he would like to try flying with!

Cheers!
LitterBug
I have had some off the wall ideas for some computery flying stuffs. Just never had time or motivation to learn how to implement it. Gonna finish up the latest project and get all that documented and then I may be up for something new to poke sticks at.

there are some sci fi crafts Id like to take a whack at but normal FC's dont have enough versatility to do all the bells n whistles that are needed to make then realistic. I also have my Nitro Frankenstein truck that has been staring at me with puppy dog eyes begging to be fixed and played with again. With the snow season fast approaching I'm thinking that needs the suspension reworked with the replacement ball joints and a livable FPV system that doesn't make your eyeballs wobble as it moves.