Legal Removal Request

Post: Hi Andrew, Thanks for getting back to me so quickly. Nothing is connected to the DAC output other than the multimeter so I don't think any additional current is being drawn from it. I am using the RPi 3B+ connected to a BitScope on USB and the ADC DAC Pi connected to the RPi via the GPIO pins. At the time the signal is generated, the BitScope is also in use by the RPi, so I wonder if the power drawn from USB affects the GPIO pins? I have not faced such an issue with a different DAC board that I've used previously of not producing the 3.3V signal required so a little puzzled if this is the issue. I am not too clear about your last explanation regarding setting the DAC output value to slightly less than 3.3V such as 3.2V. From the code, the largest value it can accept is 4095 so I assume that the set_dac_raw() function sets this voltage based on 0 - 4095, with the assumption 4095 = 3.3V. Please can you advise the appropriate value I should input to test your solution out? I have also included a copy of the code I'm using below for your reference, thank you very much for your help. #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> #include <time.h> #include "ABE_ADCDACPi.h" int DACLookup[40] = {0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896,0,2896,4095,2896}; struct timespec ts1 = {0, 2000000L}; // 414L struct timespec ts2 = {0, 8000000L}; int i; int main(int argc, char **argv){ setvbuf (stdout, NULL, _IONBF, 0); // needed to print to the command line if (open_dac() != 1){ // open the DAC spi channel exit(1); // if the SPI bus fails to open exit the program } set_dac_gain(2); while (1){ for (i=0; i<40; i = i + 1){ set_dac_raw(DACLookup[i],1); nanosleep(&ts1, NULL); } nanosleep(&ts2, NULL); i = 0; } close_dac(); return (0); }