Quote:
Originally Posted by jbman
Unfortunately, I don't have a scope. As far as testing the ground connection, what should I measure from TX and RX to ground when connected and waiting? Thanks!
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Unfortunately, the TX and RX pins 'float' when there is no serial traffic to drive them up or down. You can send data and measure the voltage at TX .. it should be around 2.5V as measured by a digital voltmeter since bits sort of average a 50% duty cycle. Not quite, since there are fixed start and stop bits .. but it's close.
If you send the same thing - like a text file of maybe 10000 of the same character ... you should get the same voltage each time you test, if everything is connected and working. If the numbers seem sort of random, then a pin is not well connected. And Gnd would be my first guess.