The Frog is a Arduino powered RC-Car project of mine.
I bought an cheep RC-Car @ Zellers and removed the Toy-Brain and replaced it with an DFRobot Arduino FIO.
Following Control option are in my mind:
- XBee and PC program
- XBee and XBee-Web Server-Relay
- BluetoothBee and Android phone
- Autonomous mode
I will see if I get everything realized.
- Hardware – Frog
- DFRobot Arduino FIO
- Digi Xbee Series 2 or SeeedStudio BluetoothBee
- Sparkfun Serial Motor Controler
- SeeedStudio Ultrasonic Sensor
- Pololu S8V3A Step-Up / Step-Down Voltage Regulator
- SeeedStudio 3.7V 1Ah LiPo
- blue, red and green LEDs
- Hardware – PC
- SeeedStudio UartSbee
- Digi Xbee Series 2
Lets Test the Frog
One of the first tests with external power supply, SeeedStudio Seeeduino 328, Grove Shield, SeeedStudio Bees Shield, SeeedStudio RFBee and a simple serial control sketch.
Frog I2C Test with external power supply
Frog I2C Test closer view
Controlling the Frog only over Serial is boring
Ok then lets add a Ultrasonic Ping sensor and update the sketch.
After couple hours later it was done and the Frog was alive. Still not perfect but alive.
- Add the Sparkfun Serial Motor Driver (I had to wait for the order)
- Add the DFRobot Arduino FIO (I had to wait again for the order)
- Finalize the wiring and put everything together
- Finish the sketch.
The Serial Motor Driver and the FIO arrived
Finally the missing parts arrived and I could finish the wiring. After putting everything into the frog and uploading the sketch I recognized that the Motor Driver was talking to fast to the Arduino – 115200bps. So I checked on Sparkfun if there is an other firmware I could use with the Motor Drive. No wasn’t. OK then modify the firmware. Lucky me the Motor Drive has an ATmega328. Problem I never programmed an ATmega328 directly before – I’m just new in this area. OK I knew how to use the Arduino with ArduinoISP and had still an Breadboard wired out of my BlinkM project. I knew enough about avrdude and if you run into problems signature problems check out grellis blog. It helped me a while ago – THX grelli. After a couple hours Google and I knew what I had to do. Little bit later the Motor Driver was talking to the FIO in 19200bps.
Next small Problem I run into was that the Current Threshold of the Motor Driver was to low and once a while the Motor Driver stopped. OK back to modify the firmware and burn it onto the ATmega328. Cool now it is working good.
Now it only suckz that I can control one motor at the same time. I had to send two serial commands each time. And again modification time for the firmware. After this was done I could control both motors with one command. Then the next problem.
Every second serial command the Motor Driver was telling me “Incorrect Command Length” – Damn it. OK then change also this routine too.
Then finally the Motor Driver was working like I want it, everything back into the Frog. But … guess … yes another problem. The Power StepUp I want to use was limited to 100mA peak. But the motors were pulling at least 120mh peak, so only one motor would work.
Now I’m waiting for a Pololu S8V3A Step-Up / Step-Down Voltage Regulator.
• Typical continuous output current: 300 mA
• Input voltage: 1.5V to 12V
• Output voltage: : 2V to 12V
I hope that no new problems are showing up and I can run the Frog with my 3.7V LiPo. I still need to program an Android App to control the Frog over Bluetooth with my cellphone. And I’m still not happy with autonoumes mode … the Frog still has to learn, but without testing on a running Frog … no chance.