Changing the frequency to ADC_CENTRAL_NO_OF_SAMPLES, I notice that the NoiseSensor.c/ProcessCH4Data method is visited twice per second. The first, it reads the correct value, and after, reads a constant value.
I also have noticed that the method AdcCentral.c/receiveProcess has been visited twice. But I have no access to BCDS_GuardedTask.c/GuardedTask_Initialize method to continue investigating.
On the other hand, I have found the Mcu_Adc.c/McuAdcDmaScanChannelCb method, that choose between two buffers to write, and the em_dma.c/DMA_IRQHandler method, that toggle the adcPtr->_DriverCtx.PointerValue value, to use one of the two buffers each time. When I set Mcu_Adc.c/McuAdcDmaScanChannelCb/currentActiveBuff local variable to 1, the values seems to be right, despite the twice method call. But, doing that doesn't seem the correct way to fix the problem. I need to use ADC to read others sensors too, and doing that, maybe will not be good.