Hi. I am going to use the Cortex M4 to process ECG signals. The reson of using an MCU is to reduce external components as much as possible. The only external components I wish to use is the instrumentation amplifier to remove any CMR and for a small signal amplification before entering the ADC. Since an ECG signal has both positive and negative cycles, it it possible to set the ADC reference from -2.5V to 2.5V?