Krumlink
New Member
The current project I am working on right now will be to maximize I/O pins without going completely serial (serial communication, not YouTube - Al Gore Im Serial!). I am using a 18F4620 connected to a 18F2525. The way in which I have parts connected, is that It requires 6 I/O pins to run the SN754410 Dual H bridge. I will be using the 18F4620 to output a binary value using 3 I/O pins, in which I will OR together with the 18F2525 and drive high the proper pins afterward. You may say it will be easier to just drive the 18F4620 with 6 I/O pins in the first place, but I am looking at the total of the 4620's pins, not about the 2525's, in a sense the 2525 is a demultiplexer.
Truth table of 4620 & 2525
0 0 0 Null
0 0 1 Forward Motor A
0 1 0 Forward Motor B
0 1 1 Backward Motor A
1 0 0 Backward Motor B
1 0 1 Forward A + B
1 1 0 Backward A + B
1 1 1 High Brake
The three inputs on the left will be the 4620, and the name is the appropriate motor that it will be driving. Otherwise, the 2525 will take the inputs and turn on the appropriate ports to replicate the results on the right. I have already implemented both systems, but I have yet to merge them together to create a demultiplexer, but I can.
Really what I am asking is for your past experiences and tips of PIC to PIC communication and any suggestions that you have.
Truth table of 4620 & 2525
0 0 0 Null
0 0 1 Forward Motor A
0 1 0 Forward Motor B
0 1 1 Backward Motor A
1 0 0 Backward Motor B
1 0 1 Forward A + B
1 1 0 Backward A + B
1 1 1 High Brake
The three inputs on the left will be the 4620, and the name is the appropriate motor that it will be driving. Otherwise, the 2525 will take the inputs and turn on the appropriate ports to replicate the results on the right. I have already implemented both systems, but I have yet to merge them together to create a demultiplexer, but I can.
Really what I am asking is for your past experiences and tips of PIC to PIC communication and any suggestions that you have.