ultrab
Newbie
I am using the below circuit to input data from a sensor. The sensor has a buffered output and can supply enough drive current for the ADC. The sensor is also temperature sensitive and I don't need or want the temperature portion of the signal, which is obviously a very slow change throughout the day. I therefore devised the 2 RC filter design so that I only pass the difference betwen the slow temperarture section and the actual wanted signal which is much faster but at most 5Hz. That part seems to work fine.
The problem seems to arise in the ADC. There is a jump in data level on a fairly regular basis (see red arrows). The below image is data taken straight from the ADC and written to file then shown on a chart. I have checked and rechecked the software and it seems fine. The same exact sofware is used on another pcb without any problems. I don't currently have an oscilloscope so can't verify if the signal enters the ADC like that or if the ADC is having zero-crossover issues when AIN1 goes above or below AIN0. Any ideas?
The problem seems to arise in the ADC. There is a jump in data level on a fairly regular basis (see red arrows). The below image is data taken straight from the ADC and written to file then shown on a chart. I have checked and rechecked the software and it seems fine. The same exact sofware is used on another pcb without any problems. I don't currently have an oscilloscope so can't verify if the signal enters the ADC like that or if the ADC is having zero-crossover issues when AIN1 goes above or below AIN0. Any ideas?