Camduino

Camduino is an interface to speak with Arduino over I2C. You can get a red ball position and state of proximity sensors. The main goal of this project is to supply an easy-to-use interface to communicate with Arduino as part of ImpRo project demonstrator.

I2C bus is also called Two Wire Interface (TWI) as in the Arduino reference/librairy.

Online doc

Download librairy

Arduino setup

Arduino board must be connected to CMUcam4 and five presence sensors on pins 3 to 7 and run CMU_Tracker_I2C.ino. The Arduino program is supplied with the librairy in Arduino program folder.

You can compile and upload the program to the board using Arduino IDE. You must intall CMUcam4 Arduino library first. If you can not reprogram your Arduino when the CMUcam4 is connected to your Arduino you can either disconnect the CMUcam4 from your Arduino or you can put the CMUcam4 into halt mode :

• Press and hold the reset button on the CMUcam4
• Press and hold the user button on the CMUcam4
• Release the reset button (do not release the user button)
• Wait until the red auxiliary LED turns on (2 seconds)
• Release the user button
• The CMUcam4 is now halted indefinitely

Press the reset button to exit halt mode.

Connect NXT and Arduino

The communication is based on I2C bus, so you have to connect them with a wire but such wires does not exist. Make your own RJ12 NXT to Arduino wire, it's easy. Here there is some help to do so.

NXT uses RJ12 wires made like this :

• white : analog
• black : ground
• red : ground
• green : 4.3V
• yellow : I2C clock line
• blue : I2C data line

Connect the red or the black wire to Arduino ground pin, the yellow to A5 pin and the blue one to A4.

Be carefull, NXT can not supply enought power to Arduino, CMUcam4 and five presence sensors, so use an external source for the board.

Trampoline settings

The Trampoline revision running on the NXT must use the custom I2C driver "from Armel". This driver is supplied with the Camduino library in I2C driver folder.

Modifying the driver at your own risk.

Arduino port and NXT

When calling init_camduino(NXT_PORT_S#) if you do NOT use NXT_PORT_S4, you should change it on the driver file i2c.c in Trampolie_folder/machines/arm/nxt/drivers/lejos_nxj/src/nxtvm/platform/nxt/i2c.c

Usage

• First, include camduino.h in your oil and C files.
• Initiate the driver library by calling init_camduino(NXT_PORT_S4), eventualy, initiate other I2C devices and finally call i2c_init().
• Then you get data from Camduino.
• Code and think hard. Good luck!