I2C DC Motor controller

Forum 2005-2010 (read only) Hardware Interfacing
1

I've been working on an update for my Jaguar's HVAC controls and built an I2C Motor Contoller for the flap motors.

It uses the PCF8575 I2C port expander to control two L298 H-Bridges. So you can control 4 DC motors with two Arduino pins. If you were so inclined you can use up to eight of these boards by changing the address of the PCF8575, giving you control of 32 DC motors with just two Arduino pins. The Eagle file below has it hard wired to an address of 0100001 because that's what I needed. But you can reroute some wires in Eagle and make it whatever address you want.

The PCF8575 I am using is an NXP package size ssop-24.
The L298's are the regular dip's
The diodes are MUR120G's ultrafast 1A

My DC motors are from a newer Jag and have a pot built into them for feedback. So some of the via's in the schematic are for power, gnd and the signal wire to the pot. If your not using something like that, you can either delete that part of the circuit or just don't hook them up to anything.

Hope someone can use or adapt this to their projects.

http://cid-700ccc82e7491bab.office.live.com/self.aspx/i2c%20motor%20driver/Motor%20Driver.sch

http://cid-700ccc82e7491bab.office.live.com/self.aspx/i2c%20motor%20driver/Motor%20Driver.brd

Thanks to Richard C, PaulS,John Boxall and a few others from the forum for helping to work out some of the newbie problems.

Any questions or errors let me know.

2

Very nice, thanks !
BTW thats an interesting power supply regulator ya got there...

3

Yes kinda dirty. But it works good. The L298 causes a 1.4v drop and the motors were moving slow. So I bumped up the voltage on the input and that solved the problem. I looked for 7807's and 7806's but I couldn't find a 2-3A version.