Inspired by the many autonomous rovers such as Curiosity and the self-driving Google car, [Rohit] decided to build his own by taking an off-the-shelf remote control car and adding his own electronics. Unfortunately, he couldn’t find the datasheet for the chip used to receive radio signals and drive the motors, so he ended up building his own electronics and putting them in the car.
[Rohit]’s car – the Thunder Rumbler RC Car – is driven by applying power to two motors. This is an easy system to control, as only two channels are needed to make the car go forward, left, right, or backwards. To drive these two motors, [Rohit] found an SN754410 quadruple half-H bridge driver chip lying in his box of assorted electronic components. Thanks to a helpful instructable, this chip was easily controlled with an Arduino.
That left the problem of sending a wireless signal to the Arduino. [Rohit] accomplished this by relying on an Android phone to provide the remote control.
[Rohit] whipped up a small program running on his desktop that allows him to send ‘L’, ‘R’, ‘U’, or ‘D’ to the Android phone to dictate if the car should go left, right, forward, or reverse. The Android phone receives these commands via the Internet and sends an audio signal through the headphone port. This audio signal is connected to two analog pins of the Arduino. With a little bit of software and a bit of reading up on frequency shift keying, [Rohit] was able to make his car move in any direction.
Even though [Rohit] realized his goal of controlling a remote control car on his own terms, the build is far from done. He plans on adding some ultrasonic sensors and using the Android’s camera for object detection.
This is so awesome. I’m working on almost exactly the same project right now, and was stumped on how to send signals from my phone to my arduino. Thanks for sharing your code! :)
I have seen (and replicated) generating true RS-232 (output only) out of android audio out. I got it up to 24000bps. One op-amp to boost voltage from headphone output to TTL levels (0-5V) and straight to hardware UART in my ATmega.
See http://www.robots-everywhere.com/re_wiki/index.php?title=Serial_on_Android_using_the_audio_port for my inspiration and https://sites.google.com/site/pwwpam/home/projekty-w-semestrze-zimowym-2011-2012/android-tv-remote for very limited writeup about my project (in Polish -look for pdf at the bottom)
Nice, this might be easier. Thanks for sharing!
I’m currently working ona similar project.trying to add autonomousreturn to a charging stationwhen low or motor gets to hot or car moves out of radio range top a mid 80’s rc car.this has given me some things top think about.but first I need to clean up some servo pass through code
The coolest platform for a project like this? A Big Trak.
BTW, Big Track is back as the Bigtrak, only in its white euro color instead of the silver/grey color the original had in North America.
I saw this page about Prestige Remote Control Cars that is very cool http://www.squidoo.com/prestige-remote-control-cars should i but one for my 8 year old son for christmas?
Me and my step son are wording how to rebuild from batteries to bigger batteries then make it bigger and stronger