How to setup the ADC & DMA on a dsPIC33?

Question

I like to sample an analogue mic sample. The sampling should be synced with the I2S master clock. Since I like to do some DSP after, a block of samples should be processed while another block should is sampled. My MCU is a DSPIC33CH128MP205.

So I tried to setup everything but I am still failing.Maybe someone can spot what I am doing wrong here or advise me.

I am using MPLAB with the MCC tool. Here the screenshots of the setup

ADC:

DMA:

PIN control:

Some init code:

uint16_t mic_in[64*2];

void DMA_Channel2_CallBack(void) {
    if (DMA_IsOperationHalfComplete(DMA_CHANNEL_2)) {
        
    }
    if (DMA_IsOperationDone(DMA_CHANNEL_2)) {
        
    }
}

void adc_init(void) {
    // ADC1_IndividualChannelInterruptEnable(channel_AN8);

    // channel 2 -> ADC channel 8 (RB3) + ADC trigger RB4 -> mic.mic_in
    DMA_ChannelDisable(DMA_CHANNEL_2);
    DMA_DestinationAddressSet(DMA_CHANNEL_2, (uint16_t) &mic_in[0]);
    DMA_SourceAddressSet(DMA_CHANNEL_2, (uint16_t) &ADCBUF8);
    DMA_TransferCountSet(DMA_CHANNEL_2, sizeof(mic_in)/sizeof(uint16_t));
    DMA_ChannelEnable(DMA_CHANNEL_2);
    //DMA_SoftwareTriggerEnable(DMA_CHANNEL_2);
    
    // ADC1_SoftwareTriggerEnable();
    ADC1_InterruptFlagClear();
    ADC1_Enable();
    //ADC1_SharedCorePowerEnable();
}