nev@zeus.hf.intel.com (nev) (09/07/89)
hi - This is the first time I am posting on the net, so I can make few mistakes... My goal is to be able to decode the infrared signals sent by remote controller unit (kenwood RC 206). If I press the key XYZ on the unit, the program running on the computer should print, "you pressed XYZ". Has anybody build such a system? Is there any chip commercially available, that I can connect the infrared sensor as input, that will give binary code for the key I pressed as output? The progress (or lack of it :-) ) on this project is: I connected sensor to the scope to see the signals transmitted by the remote control unit. The amplitude of the signals was 40 to 60 mV, and the length of the bit stream was roughly 10 ms. The signals were sinusoidal (like sine wave). I connected sensor to a transistor to get the logic levels (0 to 5 volts). I then connected this to the parallel port of the computer. The signal (bit 0) was normally HIGH and when I send a signal via remote control unit, bit 0 changed to LOW. Program I wrote monitored this line (bit 0 ) to go LOW and stored the contents of this port into an array of 4000 bytes as fast as it can. Then it displayed on the screen what was captured from this port. To my dissapointment, the sequence was quite different for the same key I pressed at different times. So capturing the signals sent by a specific key would not work for comparison purposes. There must be an easier way of doing this. Any ideas? I thought my approach was logical but I must be doing something wrong. I ordered the KENWOOD service manual to see what kind of circuitry they used. The schematic showed a rectangle with three wires connected to it as the sensor. The description of the part says "electronic circuit board" :-). Obviously this was not much help. Then I ordered that part so I can see what is on it, or just use that as a sensor. The output of this part is directly connected to the microprocessor in the stereo. For the time being, I am waiting for the sensor unit to arrive to see how they decode the signals... - nev In case I have expressed any opinions here, my employer has nothing to do with them... ___________________________________________________________________________ | | | ********* AUTOMATE FOR A BETTER WORLD FOR ALL ********* | ___________________________________________________________________________ | / | nev okyay | | __ _ , _ ____/_ __ , __. __ , | Intel Corp. HF3-59 | |/ /_</_\/ (_) / <_/ (_/_(_/|_/ (_/_ | 5200 Elam Young Pkwy | | / / | Hillsboro, OR 97124 | | ' ' | 503 696 7122 | ---------------------------------------------------------------------------