Can you guess what my latest hop up is ? suggestions welcome and more clues in a day or two



Duane.

No guesses ?

I guarantee this is maddest project yet on Dubdrift

Lets get some guesses in.

Duane.

Are those LEDs?

Hi,

Technically yes they are LEDS, but you won't be able to see any light from them.

Duane.

I should correct that, one is an led the other isn't and they are both in the invisible infrared spectrum.

another clue, my project chassis will use four pairs

Duane.

Are you planning to control your car with an IR remote system?

is that the one you told me about Duane? hope to see it running soon

Hi Lance,
No, its not an infrared remote control system, its quite a bit crazier than that.

Hi Ian,
Yes it is one part of the projects I mentioned to you, I built the first part yesterday even getting as far as road testing it in an M03.

I have tried to upload another clue, but the forum is not accepting my image for some reason.

Duane.

Hmmnn.. What could it be?

I hope you're not trying to make an M-o3 fly.. Are you?


Hahaha!



Keep us updated..

(?) any prize for who's gonna get the correct answer?

Hi Lance,

With the amount of electronics on it the car is more likley to time travel than fly.

Right now there are around 20 additional wires on the car and heres another clue -



Thats it for now, I will see what Santa brings before I commit to a prize ;-)

Duane.

I guess you are going to install a speedometer and the function of the IR leds is to measure the speed of each wheels (revolution per minute). Is it a IR transmitter and receiver?

So close Arispal, it is an IR Emitter and receiver pair and I am using them to measure the RPM of the wheel, but I am going a lot further and measuring the speed of each wheel with the intention of building traction control.

Here is a picture of my work space



And here is my current road test set up, the LEDS light up progressivley based on the speed difference between the two front wheels - < 20% no lights, 20 % or more 1 light, 40, 60 and 80 each light another light until 100%.



I have tested it extensivley on the bench and running the car outside in the street as normal.

The current set up is very heavy but can easily be built smaller and lighter than a packet of cigarettes. The micro controller I am using is an Arduino, its programmed directly from the PC through a USB Cable and then runs standalone using the lipo in the car for power.

My next stage is to synthesis the throttle signal from the receiver, I will knock up a quick test project that will allow me to remotely program the Arduino to limit the throttle range 'in car'. My vision is - my son wants to have a go of my car so I press the brake three times and the car will read this as ok so you want me to map a 100% input range from the receiver into a 30% range for the ESC. Then when I get the transmitter back I send some other combination of signals to restore full throttle - all without having to be anywhere near the car. This is a useful feature I would like to have, but its also the basis for managing the throttle signal based on a combination of user input and the wheelspin detected in my current set up.

I have several thousand other ideas and will blog a few of them and how I built and programmed them over the rest of the holiday.

Hope some of you find this interesting, I have picked up an accelerometer and gyroscope as well as the IR sensors so will be able to build data logging, RWD Traction control, anti yaw, drift control and just about anything else. I can also add sound and light effects to a car based on whats happening to the car and the current control input, for example a drift sound effect, brake effects etc etc etc.



This is the micro controller, its big and heavy but super quick for prototyping, it can also be built much smaller and cheaper once you have finalised your design.

Duane.

Hi Duane!

Nice work!!! I am using the DFRobotshop Rover which Arduino compatible with built-in ATMega328p. In fact, it is a very good programmable microcontroller board that can connected to USB port for loading the program. I am not very good in programming but I can understand the flow because I have a little background of C programming.

Great job!

I'd love to see how this goes.

Hi,

As Arispal says, the Arduino is really easy to program from a PC, its also really easy to interface to hardware. I had the first stage of the traction control system built in about six hours.

To get the sensors working I sprayed the insides of the wheels black and then stuck a strip of 'bare metal foil' inside, this works really well. At top speed with no load, the minis wheels run at 68 RPM per second and the Arduino has no trouble sensing this for both front wheels. The 'bare metal foil' is a super thin aluminium foil that is normally used for adding chrome details to 1/32 and 1/43 cars. I used it at its thin enough and light enough not to upset the balance of the wheels at high RPM, it also leaves enough room between the wheel and the hub to get my sensors in.

Sensor mounted on steering hub with prepared wheel.



As I have the traction alarm working, the next stage is to read the receiver signal into the microcontroller then output a synthesised version which I can adjust to control throttle output and maintain traction onboard the car.

I have the basics working but its a bit rough, I am using a servo rather than the speed controller for now as the signal is the same but the servo is more convenient for initial testing. I can control the servo through the full range with the microcontroller intercepting the receiver signal and recreating it, but my current implementation is a bit jittery.

Getting the receiver signal into the mirco controller



I will optimise the code but ultimatley I will want to move the job of creating the servo/speed controller signals to a dedicated external chip so that the microcontroller can focus on monitoring the car and taking high level decisions, the low level signalling will then be offloaded/delegated to one or more simpler chips.

I have lots of other projects in mind, including making the m07 drivable by altering the power delivery to the front and rear wheels depending on what the car is doing - a 1/10 scale active electronic diff.

Duane.