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Step 5Connecing the Compass Module
The HM55B Compass Module has turned out to be a necessity to get the Create to go where I want it to go. Since the Create will never turn exactly as far as you want it to, and you have no way to know if it did or not, I found I needed the compass so I would know definitively what direction I (it) was heading.
The Create Distance and Angle sensor data can be pretty accurate, as long as the flooring surface is consistent and you only perform right-angle turns at the proper speed while reeding the sensor data at the proper rate. It turned out it just wasn't consistently reliable to use an X,Y coordinates mapping system based solely on the Creates sensors. So the Compass in integral in maintain heading accurancy.
The Compass returns a reading of 0 to 359 degrees indicating what direction the Create is pointing, just like your every day magnetic compass (except you read it as North, North/East, East, etc.. The compass returns 0 for North, 45 for North/East, etc..
The HM55B Module from Parallax is an 6-pin DIP module that could be soldered directly onto the Proto Board. HOWEVER, it is very susceptible to anything metal (motors, rebar, refrigerators, lamps). The electrical characteristics of the Proto Board may affect it, but more likely the MOTORS of the Create will cause the most disturbance. And since the Proto Board is mounted in the bottom of the cargo bay, it is rather close to the motors. So, I suggest mounting it on a separate board and mounting it higher up and in-between the motors (about 3 or 4 inches seemed to do ok, your mileage may vary).
You will require five wires to connect the HM55B to the Proto Board. +5v, GND, DATA, CLOCK, and ENABLE. Mount the HM55B on a small circuit board, then bring five wires from the HM55B to the Propeller ProtoBard.
Connect pins HM55B-1 and HM55B-2 to ProtoBoard-P13.
Connect pin HM55B-5 to ProtoBoard-P14.
Connect pin HM55B-4 to ProtoBoard-P15.
Connect pin HM55B-3 to ProtoBoard-Vss.
Connect pin HM55B-6 to ProtoBoard-+5V.
Mount the board up/away from the Motors and anything that might cause magnetic/electrical disturbances. And keep it LEVEL.
The CreateOI.spin Object (software) takes care of reading the compass and adjusting our heading as appropriate while driving to maintain the requested direction/heading/bearing (so many ways of saying it).
The Create Distance and Angle sensor data can be pretty accurate, as long as the flooring surface is consistent and you only perform right-angle turns at the proper speed while reeding the sensor data at the proper rate. It turned out it just wasn't consistently reliable to use an X,Y coordinates mapping system based solely on the Creates sensors. So the Compass in integral in maintain heading accurancy.
The Compass returns a reading of 0 to 359 degrees indicating what direction the Create is pointing, just like your every day magnetic compass (except you read it as North, North/East, East, etc.. The compass returns 0 for North, 45 for North/East, etc..
The HM55B Module from Parallax is an 6-pin DIP module that could be soldered directly onto the Proto Board. HOWEVER, it is very susceptible to anything metal (motors, rebar, refrigerators, lamps). The electrical characteristics of the Proto Board may affect it, but more likely the MOTORS of the Create will cause the most disturbance. And since the Proto Board is mounted in the bottom of the cargo bay, it is rather close to the motors. So, I suggest mounting it on a separate board and mounting it higher up and in-between the motors (about 3 or 4 inches seemed to do ok, your mileage may vary).
You will require five wires to connect the HM55B to the Proto Board. +5v, GND, DATA, CLOCK, and ENABLE. Mount the HM55B on a small circuit board, then bring five wires from the HM55B to the Propeller ProtoBard.
Connect pins HM55B-1 and HM55B-2 to ProtoBoard-P13.
Connect pin HM55B-5 to ProtoBoard-P14.
Connect pin HM55B-4 to ProtoBoard-P15.
Connect pin HM55B-3 to ProtoBoard-Vss.
Connect pin HM55B-6 to ProtoBoard-+5V.
Mount the board up/away from the Motors and anything that might cause magnetic/electrical disturbances. And keep it LEVEL.
The CreateOI.spin Object (software) takes care of reading the compass and adjusting our heading as appropriate while driving to maintain the requested direction/heading/bearing (so many ways of saying it).
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