Hello and welcome to my second instructable, where we'll be modifying a cheap RC car to drive it with an Android smartphone over Bluetooth.
  Actually, this was my school project at the Lycée Jules Fil , so I had to produce a complete write-up. Unfortunately, it is in French, but if you want a really in-depth description of the system, and you understand french, you can download it HERE .

   I recommend that you read my first Instructable  for a more detailed explanation on how the thing works.

  The cost of following this instructable is something around 30~40$ if you already have the RC car.

  Disclaimer : In this instructable, you will be using dangerous chemicals (Acetone and Ferric Chloride) and dangerous tools (drill, saw, soldering iron,etc...). I can't be held responsible if you harm yourself following this guide. If you follow this instructable carefully, and protect yourself you won't get hurt.

  So, the RC car will be driven using the accelerometer sensor (like in iPhone/Android racing games) over bluetooth. For that, we'll be using an android app and arduino library named Amarino 2.0 . The system works a little bit like that : 

           |     I²C
          \ /
Android Smartphone
           |     Bluetooth
          \ /
          |     PWM / simple logic
         \ /
         \ /
Rear motor + Dir motor

Dont forget : If you liked my Instructable, please rate it , and let me know in the comments what you think about this Instructable, and what I could do to make it better ! Thanks !

Below is a little video demo :

Step 1: Required Stuff

Required tools:

- solder iron with fine tip
- tiny solder wire
- good magnifying glass
- "Third hand" helping tool
- small drill press with small bits (~0.02 inch)
- good soldering skills
- hacksaw (used for cutting and shaping the pcb)
- 400 grit sandpaper (otionnal, used for smoothing rough edges after cutting the pcb)
- latex gloves
- Laser Printer (for the Toner Transfer method )
- iron (used to transfer the toner on the pcb)

Required chemicals:

- copper etchant (I use Ferric Chloride)
- Acetone

Required Parts:

- Arduino
- cheap RC car
- Android smartphone
- Bluetooth serial adapter
- 10k and 20 kOhm resistors
- 9V battery or LiPoly 2S (7.4V) battery or 7~8v RC battery pack (Using a rechargeable battery is MUCH better)
- small wires (IDE cable style, see the photo)
- 28 break away headers
- L293E H-Bridge  (or any 16-pin L293 variant)
- 16-pin DIP socket
- 9v battery clip
- blank PCB (Printed Circuit Board)
- magazine paper (for the Toner Transfer)

Required Software:

- Arduino IDE : get it here .
- Eagle CAD freeware edition : get it here .

Now that you have gathered all this stuff, let's go to step 2.

About This Instructable


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Bio: My name is Jonathan Rico, I'm 18 and I live in France.I'm in my first year of an electronics degree. And, the ... More »
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