P. Short
07-23-2008, 08:21 PM
Lately I've become somewhat unhappy with the sprinkler controls here, so I've decided to try and piggy-back a new controller on top of some of the other projects that I've been working on.
Since the PIC that I've been using (PIC24HJ12GP202) doesn't have enough pins to nicely drive both a graphic LCD display and eight triacs, I designed a little expander board. The TO92 parts can be either Z0103 triacs or NPN transistors, so the board can be used for either low-voltage AC or DC. There are no optos on the board, so it is not good for AC line voltages. The 16-pin chip is a 595, and the 14-pin chip is a 74HCT125 (since the PIC has TTL output levels). The pinout on the RJ45 connector is the same as the coop 595 boards, except that the serial output from the 595 is brought out to pin 6. The board is 1.75x2.25", and the holes are the same as those on the Radio Shack prototype board that I've mentioned in another post.
I'm not sure if I'm going to go through with this board or just use point-to-point wiring, but I thought that I'd throw it up for comments.
Since the PIC that I've been using (PIC24HJ12GP202) doesn't have enough pins to nicely drive both a graphic LCD display and eight triacs, I designed a little expander board. The TO92 parts can be either Z0103 triacs or NPN transistors, so the board can be used for either low-voltage AC or DC. There are no optos on the board, so it is not good for AC line voltages. The 16-pin chip is a 595, and the 14-pin chip is a 74HCT125 (since the PIC has TTL output levels). The pinout on the RJ45 connector is the same as the coop 595 boards, except that the serial output from the 595 is brought out to pin 6. The board is 1.75x2.25", and the holes are the same as those on the Radio Shack prototype board that I've mentioned in another post.
I'm not sure if I'm going to go through with this board or just use point-to-point wiring, but I thought that I'd throw it up for comments.