You can then record programmes automatically by selecting them for record on the set top box with no need to programme the DVD recorder.
You will not need to open either your set-top box or DVD recorder so no warantees or contracts are affected.
Step 1: The Black Box
Step 2: Inside the Box
There are two outputs, one drives the IR LED (scrounged from an old IR handset) via a suitable resistor (about 470ohm giving about 7.5mA trhough the LED) and annother output to flash a status LED on the front panel (just so you can see the thing is still working)
Step 3: Programming the Code
To program the code in you will need a 5V supply to power the board during programming (the PSU used in normal operation is fine for this) a 12V supply for programming the EPROM and a serial connection to a PC, the RS232 levels on the programming interface are 5V so you will need a convertor with a LT1181 or similar to give true RS232 levels)
Step 4: Making the PCB
Make sure that the artwork when printed is scaled correctly in BOTH directions.
Attach the components as shown in the image.
The DWF file has scaled printable versions of the PCB, schematic and layout. For a wiewer go to www.autodesk.com