Remote IR Terminal
Some projects need a control panel,
but are in situations which make that cumbersome. Unlike bench equipment,
which would be useless without built-in readouts, other control devices
could use interfacing just to alter a few settings or take occasional
readings. This device's first job will be interfacing to my hydroponic
This unit provide 2 way IR communications using a numeric keypad and an
LCD display. Data is sent and recieved in ASCII with no regard to
what the data means to any particular device.
The ASCII data still needs some form of encoding. For this I chose
10-pulse coding of 38Khz IR using a
nifty 99 cent receiver chip , TSOP4838 The transmitting is done with a
straight IR LED with both carrier and coding
done in software.
As you can see from the diagram below, the membrane switch and LCD display
use up quite a few I/O lines even with some sharing of signals.
This required the use of a larger (28pin) PIC for this controller.
However, it means that the target device it controls needs only 2 I/O
lines for sending and receiving the IR data. Although functional
at this time, some features and nicities need to be added later.
Here is the current state of the Source file.