I have been following along with the SD card example, the RTC example, and normal LED examples. I am experiencing a strange outcome and request some help to explain it. Maybe its just something so simple? I'm rather new to Arduino. I built a datalogger to monitor the current in a circuit, and when it goes above 0.2Amps the current switch changes state. The arduino monitors it. When I have a simple sketch which just does the LED based on the digital input as interrupt, all works well. The LED lights and stays lit when current is > 0.2A. And turns out when below this 0.2A limit where the switch changes state.
Now I add in my SD card code, the RTC code, and do the datalogging on top of all this. That stuff all works fine, but now the LED flickers on for about 50 ms or so, and then goes out, any time the switch changes state. Is this normal behaviour? Am I taxing the resources too much? I've tried Serial.println() functions in various spots to see if I can find out the cause, but so far no red flags. When I compile, I get this result in the window.
Sketch uses 15774 bytes (48%) of program storage space. Maximum is 32256 bytes.
Global variables use 1205 bytes (58%) of dynamic memory, leaving 843 bytes for local variables. Maximum is 2048 bytes.