December 22, 2013
Firstly Thanks to Oddbot, Pome & the Dagu team for this amazing Robot.
Assembly time was about 16 hours, that included rebuilding the right wrist to get the servo in a position to be able to pour a liquid ;-)
The Instructions were relatively easy to follow (As they evolved) and it was an enjoyable experience. My only suggestion's to fellow droid builders are: 1) Have some way to measure all the screw's and spacers on hand. My Cutting mat was perfect for this. 2) Think about the servo positions for the task's you want the grippers to achieve.
Now on to the Control, A Custom PCB :-) This is still a work in progress so any suggestions would be great.
So far the concept is to have an Atmega1284 as the Brains and a dedicated Atmega328 for driving the motors/encoders/Bump Prox sensors. I also plan on using two power supplies, 1 for motors and servo's and 1 for uC's. I have only designed the Motor drive part of the circuit so far. (Click image for higher Res)
I'm using a L298N wired in parallel for each motor, allowing them to handle the Rover 5's 2.5A stall current and I'm also monitoring the Current in case a proximity sensor fails. The Encoders are connected via a XOR gate as Oddbot was so kind to suggest in the manual and all connected to Port D of the 328 to reduce time/code required for the port manipulation encoder counting. I've also included 4 plugs for 4 x sharp IR 4- 30cm sensors, I plan to "cross" these sensors on the front and back of the droid allowing it to avoid running into objects. Alternatively the same 4 pin's are broken out near the front of the board to have the option of line following or 2 of each, etc. The only 2 pins left free are Rx/Tx which I'm guessing might come in handy to attach a serial LCD for debugging.
The Main uC will be in charge of Vision and Mapping. For the vision I plan on using a combination of a Pixy Cam and a Rocket Brand Studios WiiCam. And I'll try implement a wavefront for the mapping. I'd also want to include Bluetooth.
I'm still undecided if the Main uC will handle the servo control or if I'll include another 328 that would allow for the servo with feedback modification.
If anybody has any suggestions to add/improve/modify this they would be greatly appreciated :-)