Using I2C on m3pi expansion board with mbed

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1

I’m using the m3pi expansion board with the LPC1768 and the xbee. I would like to use one of the I2C ports for some sensors. But both I2C ports are occupied by the LPC1768 and xbee for serial ports. So what I’m thinking is hack the board by using P13 and P14(give up some leds) for a serial port to connect either to the xbee or LPC1768. This means I would have to cut some traces and run some wires. Is the m3pi expansion board 2 layer or a 4 layer board? Any better ideas to get access to a I2C port?

I thought about one of the other prototype boards but then you have to add more hardware, 3.3v reg, etc.

Thanks,

Jerry

2

Hello, Jerry.

Since I2C is a clocked protocol, it is fairly easy to do I2C in software, which would allow you to do I2C on any two digital I/O pins. It looks like someone has written a Software I2C mbed library.

- Ryan