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Joined: 04/12/2021
Location: United StatesPosts: 47
| Posted: 03:24am 18 Apr 2025 |
ERROR? setting the araw configuration on the RP2350B grounds the analog input pin
It appears that using the setpin gpxx,araw command on the RP2350B version sets the input pin to output a digital zero
I am trying to read the ADC channels on a RP2350B (Weact Studio RP2350B Core Board from AliExpress)
I have a 10k pot set up as a voltage divider from 3.3V to GND, wiper is connected to the ADC pin indicated
Using a conventional (original) Pi Pico with RP2040 and V6.00.02RC15
> setpin gp26,ain
> ?pin(gp26)
1.595604396
Voltmeter on gp26 reads 1.599v
> setpin gp26,araw
> ?pin(gp26)
1982
Voltmeter on gp26 reads 1.598v. 3.3 / 1.598 * 1982 = 4101 (~4095, as expected)
So far, so good. All works as expected.
Using a Weact Studio RP2350B Core Board
Voltmeter on gp26 reads 1.552v Still as expected
> setpin gp41,ain
> ? pin(gp41)
1.534358974
Voltmeter on gp26 reads 1.552v Still as expected
> setpin gp41,araw %%%%%% As soon as this command executed, gp41 drops to 0.078 volts using external voltmeter
> ? pin(gp41)
95 %%%%%%%% Should be ~ 2000
Voltmeter on gp26 reads 0.078v %%%%% should be ~ 1.55 V
> setpin gp41,ain
Voltmeter on gp26 goes back up to 1.556v
N.B. the arithmetic is correct, 3.3 / 0.078 * 95 = 4019 (~4095, as expected)
It looks like the software routine for the command [setpin gp41,araw] causes the pin GP41 to output a logical 0
PS: On page 136 of the manual Ver 6.00.01
"ARAW Fast analog input returning a value between 0 and 1023."
should be "ARAW Fast analog input returning a value between 0 and 4095."