Posts: 33
Registered: ‎03-06-2017

Multiple Autoscan Buffers


          I'm trying to sample at a high rate (1.1 MSPS) in 10-bit mode using the EFM8 Laser Bee MCU. I wrote some code based on the example programs that uses autoscan mode and polls the ADC allowing a new autoscan to start at the next buffer address when each scan finished. I find that I get an approximately 1-sample gap in my waveform that occurs when the CPU is switching the autoscan buffers (I got a 5-sample gap when I used an interrupt based sampling algorithm). I was wondering if there is any way to run 2 autoscan buffers for the same ADC channel at the same time. For example, if I were to use 2 32-word buffers and offset them by something like 30 samples. I could start the 2nd autoscan buffer filling before the first had finished and then stitch the data together. Looking at AN919 and the Laser Bee Reference manual it looked to me like I could only run a single autoscan at a time, but I wanted to see if anyone had tried something similar to what I describe above. Thanks!

Posts: 343
Registered: ‎03-03-2015

Re: Multiple Autoscan Buffers

The closest I've seen is the circular buffer, where the ADC ping-pongs between two buffers.  I don't think it is possible to write the results to two different buffers at the same time.