Some years ago I hacked the CM-5 from the Robotis Bioloid kit and added simple bluetooth comms using a Sparkfun BlueSmirf. With the upgrade of my Bioloid to the new CM-510 I decided to see if I could connect a BlueSmirf to this as well.

The connection to the BlueSmirf is pretty straight forward. The pin allocations for the CM-510's comm port are in the user guide that comes with RoboPlus. The comms plug is a little tricky to get hold of. I was lucky, I had a hunt in my scrap box and found an internal USB cable for a Shuttle XPC. One end had the correct plug but it was a 5 pin not a 4 pin. I removed all the metalwork from the housing and with a sharp knife as able to trim the plug to fit.

Having got the plug sorted and hooked up the BlueSmirf, I had some trouble getting data to be recognised at the other end.

Firstly, this is a packetised format. The CM-510 uses the same data packet format as the CM-5, which is well documented. (If you need it look for my original Bluetooth hack for the CM-5 as that documentation contains the format. It's linked at the bottom of this blog article.)

Secondly, the CM-510 defaults to expecting IR comms if the Zig110 is not plugged in, regardless of whatever else is plugged into the port. Thankfully, Robotis have already dealt with this, but unfortunately as my kit is a Bioloid Comprehensive with the Robosavvy upgrade I didn't have much documentation to refer to. Robotis kindly supplied me the answer, which is to set the RC100 Channel to 255 in the RoboPlus Task program. This sets the comms port up for 57600 baud serial comms.

Once that was done it was all plain sailing, and my now very ancient BioBluePC program (which I really must update) can send data to the CM510