Board: UNO R2
Sketch: Frequency Counter sketch for Atmega328 by Nick Gammon (Gammon Forum : Electronics : Microprocessors : Timers and counters)
Compiler: Arduino 1.0.5
Test setup: 555 timer on breadboard, 5V source, output from 555 timer to pin 5 on UNO, shared ground from breadboard to POWER GND on UNO
Problem: The UNO is displaying the frequency in the serial monitor for a while, then the TX LED goes steady lit. By "a while" I mean from a few seconds to less than a minute.
I tried a different sketch from FreqMeasure Library, for Measuring Frequencies in the 0.1 to 1000 Hz range, or RPM Tachometer Applications, and the same problem.
I am wondering if the breadboard setup is too noisy and somehow affects the UNO? The wires to the UNO are 3-4" long.
I have not found other posts with this problem (google search), so if anyone have a suggestion, please share!