Function sampleColumn

Scan/Deprecated/DPH/scan_loop.c:696–753

void sampleColumn( uint8_t column )
{
	// ensure all probe lines are driven low, and chill for recovery delay.
	ADCSRA |= (1 << ADEN) | (1 << ADSC); // enable and start conversions

	PORTC &= ~C_MASK;
	PORTD &= ~D_MASK;
	PORTE &= ~E_MASK;

	PORTF = 0;
	DDRF  = 0;

	recovery( OFF );
	strobe_w( column );

	hold_sample( OFF );
	SET_FULL_MUX( 0 );

	// Allow strobes to settle
	for ( uint8_t i = 0; i < STROBE_SETTLE; ++i ) { getADC(); }

	hold_sample( ON );

	uint8_t mux = 0;
	SET_FULL_MUX( mux );
	getADC(); // throw away; unknown mux.
	do {
		SET_FULL_MUX( mux + 1 ); // our *next* sample will use this

		// retrieve current read.
		uint16_t readVal = getADC();
		samples[column][mux] = readVal;

		// Update max sense sample table
		if ( readVal > sampleMax[column][mux] )
		{
			sampleMax[column][mux] = readVal;
		}

		mux++;

	} while ( mux < 8 );

	hold_sample( OFF );
	recovery( ON );

	// turn off adc.
	ADCSRA &= ~(1 << ADEN);

	// pull all columns' strobe-lines low.
	DDRC |= C_MASK;
	DDRD |= D_MASK;
	DDRE |= E_MASK;

	PORTC &= ~C_MASK;
	PORTD &= ~D_MASK;
	PORTE &= ~E_MASK;
}