Currently testing an accelerometer and program. It is set up on breadboard with 3D accelerometer, PICAXE 14M Firmware 9.B
program applies;
let dirsc = %00000000 'change leg 8,9,10 to input for ADC1,2,3
to allow for 3 readadc10 instructions on legs 8,9,10 (ADC 1, 2, 3).
Serin attached via programming cable via enhanced download circuit
serout connected to LCD input (Anderson K107)
Input 4 is high (connected to 5V)
Input 2 is high (connected to 5V)
Other inputs individually tied to ground via 10k resistors
Program reads in 3 separate ADC values (the 3 axes of the accelerometer) and displays these on the LCD with typical voltages from 1.6V through 2.0V.
Everything operates as expected except that at one point I found all three readings sent to the LCD had jumped up by approximately the same amount.
Tested all the voltages etc and everything was as expected. Eventually I discovered the 5V supply jumper had become dislodged from leg 1 of the 14M but the chip had not turned off!
Once 5V was reconnected everything returned to normal.
A readadc10 Value of 332 (at 5.06V) increased to 403 with no 5V
This would suggest the 14M was still seeing a reduced supply voltage and in fact a reading of 4.32v can be seen with a DMM on leg1 when there is no supply on it.
This voltage does not quite tally with the calculated changed supply voltage required to generate the readadc10 value of 403 but it is close.
Does anyone have an explanation for this behaviour?
program applies;
let dirsc = %00000000 'change leg 8,9,10 to input for ADC1,2,3
to allow for 3 readadc10 instructions on legs 8,9,10 (ADC 1, 2, 3).
Serin attached via programming cable via enhanced download circuit
serout connected to LCD input (Anderson K107)
Input 4 is high (connected to 5V)
Input 2 is high (connected to 5V)
Other inputs individually tied to ground via 10k resistors
Program reads in 3 separate ADC values (the 3 axes of the accelerometer) and displays these on the LCD with typical voltages from 1.6V through 2.0V.
Everything operates as expected except that at one point I found all three readings sent to the LCD had jumped up by approximately the same amount.
Tested all the voltages etc and everything was as expected. Eventually I discovered the 5V supply jumper had become dislodged from leg 1 of the 14M but the chip had not turned off!
Once 5V was reconnected everything returned to normal.
A readadc10 Value of 332 (at 5.06V) increased to 403 with no 5V
This would suggest the 14M was still seeing a reduced supply voltage and in fact a reading of 4.32v can be seen with a DMM on leg1 when there is no supply on it.
This voltage does not quite tally with the calculated changed supply voltage required to generate the readadc10 value of 403 but it is close.
Does anyone have an explanation for this behaviour?
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