Hi to everybody!! I'm really concerned about an issue with my MCU. When I use direct current in two channel inputs of the ADC converter, I can see the data and the measurement of the two channels in a right way (I use Matlab and Docklight to receive the signal trough the USART). The problem appears when I start to measure a sine wave, then just one of the two channels works and the other one measure zero. I use now an operational adder circuit before the input of the ADC and without it, that channel wich works, send the highest value (4095) while the other one remains at zero. What could be the problem, should I add an adder non inverter at the input of the ADC channel, it's the MCU? I really appreciate your help and thank you very much from now!!