I have two Arduino setup on two separate computers...
computer 1) Arduino with 1 bright LED on PWM pin computer 2) Arduino with 3 bright LED on PWM pins (only 1 ever on at a time) & an ultrasound sensor
Both Arduino after running in the gallery for a while are dying. Now, they are still listed in windows in the device manager and you can still send a serial message to it without errors, but it feels like it looses the code loaded on to it as it doesn't send back the serial message debug reply. If I reload the code back on, it works for a while and does the same thing again.
Here is a quick rough diagram of both circuits. The top circuit for computer 2 I haven't shown the ultrasound as I think the leds are the issue as both Arduino setups are failing in the same way.
We are using MOSFET IRF520, 0.25W 56ohms resistors and these superbright leds: http://tinyurl.com/37tg66
Power dissipation: 130mW Peak forward current: 100mA Continuous forward current: 50mA
The Arduino code is very simple, here is the code for computer 1. It was written over a year ago, but should be ok http://www.chrisoshea.org/storage/arduino_forum/arduino.pde
Someone suggested to change from USB powered to external power, so we now have a external regulated power supply but still have the same problem... M-Volt 1.25A SMPS Code: L49BR http://www.maplin.co.uk/Search.aspx?criteria=L49BR&source=15&SD=Y
Does anyone have any good ideas?
Below are some circuit photos too.