WP 34S - Successful installation of infrared port


This may be redundant, given the amount of detailed pictures and texts that have been posted so far. Anyway, here is what I have done, using what I had at home:

The 5-mm IR LED came from an old Pinnacle Systems remote control (it will be replaced with a 3-mm LED when I find one). The wires were taken from an 80-wire IDE cable. They are thin and easy to solder on small tabs. As I didn't have the recommended 390 ohm resistor I used one 470 ohms and one 2k2 resistor, connected in parallel.

The hole for the LED was made with the tip of the soldering iron. Because I intend to use a smaller LED later, the LED is kept inside the calculator, but printing is possible at a short distance, with the sliding lid removed.
That's a nice extra feature! Thanks Marcus, the WP 34S team and all who have contributed to make it possible!




You answered my question about the resistor value and I similarly plan using a TV remote LED so your short range small hole was a great touch. Your pictures also show the casing's hinge points.

Very helpful and thanks,




You're welcome! If you plan to use a 5-mm LED then drill the hole with the proper diameter so that the IR LED fits tightly in place, its tip being outside, as in an ordinary remote.




Too bad I read this after posting the letter. I could have sent you an extra LED...


Thank you, Harald. I think it won't be difficult to find one locally:


Just a walking distance from home :-)

Which color is better? Blue, like the one I have installed, or white?


The color does not really matter. More important is the low power performance (at 4mA). The TSAL4400 is supposed to give the best results for the WP34S. But if you don't want to place the printer on the other side of the desk, you can just try any diode with a wavelength of 940 to 950nm.


Wow, your keyboard is seriously beat up.


Time to replace the overlay.

My best one has been updated to the latest firmware and is waiting for Harald's board :-)

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