Generally, the algorithm is to run each pin of the device through two resistors, one about 680 ohms, one about 470K.? Each of the ends of those resistors goes to a separate I/O pin.? Each device pin also goes directly to the A/D converter.
Depending on which pin is connected, (with an active pullup, or not, or with an active pulldown or not (IIRC),? you can measure the forward voltage drop of a diode through either about 8 ma or about 10 ua.
Once you identify the base by diode tests, you likely pick the collector (10 ua into the base, 680 ohms collector, likely ground the emitter), as the lead that gives the highest beta.
Clever.? The schematics are on the web, but the algorithms are not.
Not super accurate, but useful...
Harvey
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On 10/28/2021 10:08 PM, Tom Lee wrote:
Wouldn¡¯t tell me much anyway! Need to know how it tests.
Just try a 2n3904 or pn2222. Faster than trying to understand your tester!
Tom
Sent from my iThing, so please forgive brevity and typos
On Oct 28, 2021, at 18:29, nanovnauser@... wrote:
the tester is a atmega bases one from china,was going to attatch a pic but cant see how on here.
