Hi,
Just before maiden of my Funjet APM stopped working. After few hours of debugging I figured out I2C devices are not working, preventing APM to initialise. After all I wrote simple program
void loop() {
digitalWrite(20, HIGH); // set the LED on
digitalWrite(21, HIGH); // set the LED on
digitalWrite(15, HIGH); // set the LED on
digitalWrite(14, HIGH); // set the LED on
delayMicroseconds(5);
digitalWrite(20, LOW); // set the LED off
digitalWrite(21, LOW); // set the LED off
digitalWrite(15, LOW); // set the LED off
digitalWrite(14, LOW); // set the LED off
delayMicroseconds(5);
}
After executing an all pins except SCK there were nice rectangles. SCK seems to be crippled as seen in attachment. This was measured without Oilpan.
Please confirm that my only chance is to replace Atmega. Replacing won't be issue, but I hate to order it.
I still trying to figure out what can be cause. My first idea was static discharge as i was wearing fleece jacket. But I've been said that most modern parts should not be destroyed by ESD. Another possible but very very unlike is short of SCK pin to +lipo.
Replies
> most modern parts should not be destroyed by ESD.
Most parts have actually gotten more and more susceptible to ESD. The smaller, thinner and more complicated they make the part the more easily it is destroyed by ESD. Because of this some parts have additional ESD protection built into them.
ESD can cause intermittent failures, partial damage, or otherwise be hard to spot during testing, that's what makes it such a PITA.