Re: Failed to init device yet again


Martin Bonfiore
 

I would appreciate it if you could measure the voltage (on a powered, problem board) across either your 10K resistor or the 100K when powered and the programming jumper set to the nominal 3.3V position, noting which resistor is in place.  Then we can use ohms law to calculate the input current to the chip for that pin.  A healthy chip should read less than 10. millivolts for the 10K resistor; less 100 millivolts for the 100K resistor.  If you read less than those values, it implies that the input current to the chip is OK but that the threshold voltage (the level that the chip needs to see to determine that the pin is "on") is higher than specification (2.15 volts) given that the chip is running at 3.3 volts (nominal).   

Or....measure the voltage on each side of the given resistor to a ground pin, again noting which resistor is in place.  This measurement will probably be more accurate since the first described measurement is in the millivolt range, whereas this one should be in the volts/tenths of volts range.

I appreciate you hanging in there and making these measurements to satisfy my curiosity.

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