Embedded Linux bare Metal Development (14)--ADC

Embedded Linux Bare Metal Development (14)--ADC First, Introduction to AD conversion

ad conversions are analog -to-digital conversions , is to convert analog signals into digital signals. A/D converters are used to convert analog quantities into digital quantities through a certain circuit. Analog can be voltage, current and other electrical signals, can also be pressure, temperature, humidity, displacement, sound and other non-electrical signals. Before the A/D conversion, the input signal to A/D converter must be converted to a voltage signal by various sensors to the various physical quantities. After A/D conversion, the output digital signal can be 8-bit, 10-bit, 12-bit, 14-bit and 16-bit.

Second, ADC Controller

ADC Controller clock:

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The clock source is Pclk_psys, and the ADCCLK is obtained after a one-time crossover.

the S5PV210 supports 10 ADC channels, Ain[0] - ain[9] (analog type), can support simultaneous 10-way AD conversion.

TSADCCON0 : ADC Converter Settings Register

TSDATX0 : Conversion of the resulting digital amount

CLRINTADC0 : Clear ADC0 Channel Interrupt

Adcmux : Analog input channel selection

Third, ADC Programming 1. Initializing the Controller

void Adc_init (void)

{

TSADCCON0 |= (1<<16); set The precision of the digits

TSADCCON0 |= (1<<14); turn on prescaler settings for ADC converters

TSADCCON0 &= ~ (0xff<<6);//

TSADCCON0 |= (65<<6);// Set the Prescaler parameter, the prescaler coefficient is 65+1

TSADCCON0 &= ~ (1<<2);// set Normal mode

TSADCCON0 &= ~ (1<<1);// turn on ADC

Adcmux &= ~ (0x0f<<0); Select Channel 0

}

2. Engineering Implementation

Project source code to The UART transplant printf is modeled, but the Smart210 does not have an ADC interface, so the code cannot be tested.

ADC Conversion Source:

void adc_printf (void)

{

int Val;

Adc_init ();

while (1)

{

turn on ADC conversion

TSADCCON0 |= (1<<0);

waiting for AD conversion to complete

while (!) ( TSADCCON0 & (1<<15));

Read the ADC Conversion number

val = TSDATX0;

Processing Display

printf ("val =%d\r\n", (Val & (0xfff<<0)));

Delay

Delay (0X1FFFFF);

}

}

Engineering source See annex

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Embedded Linux bare Metal Development (14)--ADC