Raspberry Pi RC Car Help

[iHAQ786]

Hi i am kind of new to the Raspberry Pi and have been asked to create a project relating to the raspberry pi.

So have thought to build a pi car which the user would eventually be able to navigate through using their iPhone's Gyro tilt features.

i have purchased a car from NtroTech and have the following components such as a servo board (LINK: http://electronics.chroma.se/rpisb.php)

and the car that i purchased for the pi was this (LINK: http://www.nitrotek.co.uk/xstr-electric ... buggy.html)

I was wondering if there is anyone who knows a lot about Pi and is able to help to complete this project. Its a uni project and its getting to the time where i just need to get it up and working.

So please if anyone is out there who is able to help me out i would be so great.

Hope to hear from someone soon.

Thanks for taking the time to read this post, really appreciate it

[BMS Doug]

So your car comes with a 7.2v Battery and you need a 5v supply to run the raspberry Pi... you need a 5v UBEC.

did the car come fully set up with RC control?
If Yes: you will need to disconnect the servo's from the RC control and connect them to your servo board.
Else: you will need to get suitable servos to control throttle and steering, connect them to your car and to the servo board.

Locate Pi and Servo Board. You'll need to put them somewhere, preferably with vibration dampening to prevent everything from falling apart.

Wifi connection: probably your best bet for connecting to an external device (the I-phone) you need a USB Wifi dongle (from the approved list) to connect to the car.

Programming: hopefully you'll get some help here.

[iHAQ786]

Thank you for getting back to me

I have ordered the following part as you stated which was the (JMT New RC 3A U-BEC External UBEC 2-6S Input: 5-23V Output 3A 5V Lipo)

I will get re-wiring on the car and disconnect the servo control from the car and connect the servo which i have to the car and see how it goes on...

Do you have any tutorials on how to wire the car up with the U-BEC plzz?

Thanks again

[BMS Doug]

So the UBEC is used to reduce the voltage from 7V2 (RC Car Battery) to 5V,

Explanation of UBEC

Wiring it: I'd find the connector for the battery and add the UBEC High voltage side directly to the same terminals (solder on?), the 5V side should feed your Servo Board and Pi (ideally feed the servo board with link removed and then continue the same 5V supply into the Pi micro USB, so that the Pi's polyfuse is still protecting the Pi.

from servo board manual.

Power: RPi powered via micro-USB, Servos powered via connected ESC/BEC.
Jumper: No jumper!
Note: RPi is driven from micro-USB, servos are driven from ESC's BEC.

Power: RPi and servos powered via connected ESC/BEC. (BEC must be 5V stable)
Jumper: Between 1 and 2.
Note: Do not connect micro-USB!

Note: the UBEC I mentioned is untested by me, I have one on order but I am planning to test it thoroughly before trusting it with my Pi. Edit: Passed Test, I'm happy with this UBEC.

I'm looking at this manual,and it's pretty useless as a manual, hopefully you have a better one with your model.

The motor speed (forward and backward is handled by the electronic speed control (ESC), this may be integrated with the radio gear (bad for you) or separate (hurrah!) if it is separate then you can disconnect the radio gear and connect the ESC to the servo board (need details of the ESC to check how easy it is to connect).
If the ESC is integrated with the radio receiver then you will need a new ESC as well.
The last RC car I had (25+ years ago) had a servo driven resistor board for speed control, I don't think they use these anymore

[Tarcas]

Is there any reason the Pi has to be mounted on the car? If the car is already remote-controlled, why not put the Pi, relay board, and remote off to the side? Use the phone to control the Pi, which in turn controls the relays, which in turn controls the original remote, which in turn controls the unmodified car? Sounds complex, but easier than mounting all that on the car any reproducing everything the car's electronics already know how to do.

[BMS Doug]

Note: the UBEC I mentioned is untested by me, I have one on order but I am planning to test it thoroughly before trusting it with my Pi.

Tested it at the weekend, stable through 3 hours of running electric motors through the UBEC, I'm now willing to trust my Pi to it.