Hello,
I've salvaged a tiny IR sensor from an inexpensive hand held remote thermometer made by Cen-Tech; I got it from Harbor Freight. It's a great little device but I need to be able to send the output to an XBee BlueTooth-type transceiver, and thence to another BT transceiver, connected to a Linux laptop, via a USB port. Alternatively, I may use my Boarduino microprocessor and a TTL/USB converter cable to feed into the laptop.
Then, I need an active bar graph GUI app in order to show the change in temperature on the laptop screen. The whole idea is that I cannot use the tiny LCD readout on the handheld remote thermometer in the project I'm working on.
I have most stages of this already worked out except two key points: I will have to come up with the display GUI app, modify one, or learn how to write my own in C, or Java, or ?
More pressingly, I need to use the salvaged thermopile (I cannot identify mfgr, or anything else) in a home brew circuit. I've found several candidates after combing the Net for days, but no values are given for the components. I have some 741 and LM324 OP Amps and I'd like to be able to use them, if possible, especially the LM324 b/c it only takes a single voltage source. But if I have to, I'll get something else.
My thermopile has four leads in a tiny TO-5-shaped case, but it's only about 3-4 mm diameter. Before removing it from the commercial unit I measured voltages to identify the pins. Pin one, just clockwise from the index tab on the case, is V+, pin 2, still going clockwise, I think is the internal compensation resistor; pin 3 is V-, and pin 4 is electrically identical with the case.
I have posted a copy of one candidate circuit on Flickr, at:
https://farm4.static.flickr.com/3032/2578992837_e32e910910_m.jpg
Thanks very much for your consideration and assistance.
Les Garwood