tkl_adc | ADC Driver

Description

Introduction

ADC, Analog to Digital Converter, generally refers to an electronic component that converts a continuous-time, continuous-amplitude analog signal into a discrete-time, discrete-amplitude digital signal.

A/D conversion typically involves four processes: sampling, holding, quantization, and encoding. In actual circuits, some of these processes may be combined, such as sampling and holding, and quantization and encoding, which are often implemented simultaneously during the conversion process.

Classification

Direct ADC	Parallel Comparator ADC
	Successive Approximation ADC
	Flash ADC
Indirect ADC	Dual Slope ADC

Technical Specifications

Resolution: Theoretically, the resolution of an ADC to the input signal, generally 8-bit, 10-bit, 12-bit, 16-bit, etc.

Accuracy: The difference between the actual analog voltage and the sampled voltage, where the maximum difference is the absolute accuracy, and the percentage of the maximum difference to the full-scale analog voltage is called the relative error.

Conversion Time: The time required for each sample, indicating the conversion speed of the ADC, related to the ADC's clock frequency, sampling period, and conversion period.

Data Output Mode: Parallel output, serial output.

Operating Voltage: Attention should be given to the ADC's operating voltage range and whether it can directly measure negative voltages, etc.

API Description

tkl_adc_init

OPERATE_RET tkl_adc_init(TUYA_ADC_NUM_E port_num, TUYA_ADC_BASE_CFG_T *cfg);

• Function Description:

  • ADC Initialization

• Parameters:

  • port_num: ADC port number, each port corresponds to an ADC entity device (usually with multiple channels), values as follows:

    Name	Definition	Remarks
    TUYA_ADC_NUM_0	ADC Port 0
    TUYA_ADC_NUM_1	ADC Port 1
    TUYA_ADC_NUM_2	ADC Port 2
    TUYA_ADC_NUM_3	ADC Port 3
    TUYA_ADC_NUM_4	ADC Port 4
    TUYA_ADC_NUM_5	ADC Port 5

  • cfg: ADC base configuration, values as follows:

    typedef struct {
        TUYA_AD_DA_CH_LIST_U  ch_list;  // ADC channel list
        uint8_t ch_nums;        // Number of ADC channels to be sampled
        uint8_t  width;         // Resolution (bit width)
        uint32_t freq;          // Sampling frequency
        TUYA_ADC_TYPE_E type;	// ADC sampling type
        TUYA_ADC_MODE_E mode;   // ADC sampling mode
        uint16_t   conv_cnt;    // ADC number of samples
        uint32_t   ref_vol;     // ADC reference voltage (unit: mv)
    } TUYA_ADC_BASE_CFG_T;

    TUYA_AD_DA_CH_LIST_U：

    typedef union {
        TUYA_AD_DA_CH_LIST_BIT_T bits;
        uint32_t data;
    }TUYA_AD_DA_CH_LIST_U;

    typedef struct {
        uint32_t ch_0             : 1;
        uint32_t ch_1             : 1;
        uint32_t ch_2             : 1;
        uint32_t ch_3             : 1;
        uint32_t ch_4             : 1;
        uint32_t ch_5             : 1;
        uint32_t ch_6             : 1;
        uint32_t ch_7             : 1;
        uint32_t ch_8             : 1;
        uint32_t ch_9             : 1;
        uint32_t ch_10            : 1;
        uint32_t ch_11            : 1;
        uint32_t ch_12            : 1;
        uint32_t ch_13            : 1;
        uint32_t ch_14            : 1;
        uint32_t ch_15            : 1;
        uint32_t rsv              :16;
    }TUYA_AD_DA_CH_LIST_BIT_T;

    The channel list can be operated using bit manipulation or through the data field, both have the same effect.

    ch_nums is the number of channels to be sampled.

    TUYA_ADC_TYPE_E：

    Name	Definition	Remarks
    TUYA_ADC_INNER_SAMPLE_VOL	ADC samples internal voltage (e.g., power supply voltage)
    TUYA_ADC_EXTERNAL_SAMPLE_VOL	ADC samples external voltage (e.g., external pin voltage)

    TUYA_ADC_MODE_E：

    typedef enum {
        TUYA_ADC_SINGLE = 0,       ///< Single conversion mode
        TUYA_ADC_CONTINUOUS,       ///< Continuous conversion mode
        TUYA_ADC_SCAN,             ///< Scan mode
    } TUYA_ADC_MODE_E;

    Name	Definition	Remarks
    TUYA_ADC_SINGLE	Single channel sampling
    TUYA_ADC_CONTINUOUS	Single channel multiple sampling
    TUYA_ADC_SCAN	Scan mode sampling	Multiple channel sampling

    conv_cnt specifies the number of samples in the sampling mode.

• Return Value:

  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_deinit

OPERATE_RET tkl_adc_deinit(TUYA_ADC_NUM_E port_num);

• Function Description:
  • ADC De-initialization
• Parameters:
  • port_num: ADC port number
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_width_get

uint8_t tkl_adc_width_get(TUYA_ADC_NUM_E port_num);

• Function Description:
  • ADC Query Resolution (bit width)
• Parameters:
  • port_num: ADC port number
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_ref_voltage_get

uint32_t tkl_adc_ref_voltage_get(TUYA_ADC_NUM_E port_num);

• Function Description:
  • ADC Query Reference Voltage
• Parameters:
  • port_num: ADC port number
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_temperature_get

int32_t tkl_adc_temperature_get(void);

• Function Description:
  • ADC Query Temperature (refers to querying the chip temperature here)
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_read_data

OPERATE_RET tkl_adc_read_data(TUYA_ADC_NUM_E port_num, int32_t *buff, uint16_t len);

• Function Description:
  • ADC Read Data
• Parameters:
  • port_num: ADC port number
  • buff: ADC data buffer
  • len: Length of the ADC data buffer
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_read_single_channel

OPERATE_RET tkl_adc_read_single_channel(TUYA_ADC_NUM_E port_num, uint8_t ch_id, int32_t *data);

• Function Description:
  • ADC Read Data (Single Channel)
• Parameters:
  • port_num: ADC port number
  • ch_id: ADC channel number
  • data: ADC data buffer
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

tkl_adc_read_voltage

OPERATE_RET tkl_adc_read_voltage(TUYA_ADC_NUM_E port_num, int32_t *buff, uint16_t len);

• Function Description:
  • ADC Read Voltage
• Parameters:
  • port_num: ADC port number
  • buf: ADC voltage buffer
  • len: Length of the ADC voltage buffer
• Return Value:
  • OPRT_OK - Success
  • Others, please refer to the OS_ADAPTER_ADC section in the file tuya_error_code.h

Examples

Example 1

void tuya_adc_single_channel_test(void)
{
    OPERATE_RET ret;
    TUYA_ADC_BASE_CFG_T adc_cfg;
    uint32_t adc_value = 0;
    uint16_t channel = 0;

    adc_cfg.ch_list.data = 1; // or adc_cfg.ch_list.bits.ch_0 = 1;
    adc_cfg.ch_nums = 1;
    adc_cfg.type = TUYA_ADC_INNER_SAMPLE_VOL;
    adc_cfg.mode = TUYA_ADC_SINGLE;
    adc_cfg.width = 10;
    adc_cfg.conv_cnt = 1;

    ret = tkl_adc_init(ADC_NUM_0, &adc_cfg);
    if(ret != OPRT_OK) {
        // failed
        return;
    }

    ret = tkl_adc_read_single_channel(ADC_NUM_0, channel, &adc_value);
    if(ret != OPRT_OK) {
        // failed
        return;
    }

    // Output the value of adc_value

    ret = tkl_adc_deinit(ADC_NUM_0);
    if(ret != OPRT_OK) {
        // failed
        return;
    }
}

Example 2

#define ADC_CHANNEL_NUM 3

void tuya_adc_multi_channel_test(void)
{
    OPERATE_RET ret;
    TUYA_ADC_BASE_CFG_T adc_cfg;
    uint32_t adc_value[ADC_CHANNEL_NUM] = {0};

    adc_cfg.ch_list.bits.ch_0 = 1;
    adc_cfg.ch_list.bits.ch_1 = 1;
    adc_cfg.ch_list.bits.ch_2 = 1;
    adc_cfg.ch_nums = ADC_CHANNEL_NUM;
    adc_cfg.type = TUYA_ADC_INNER_SAMPLE_VOL;
    adc_cfg.mode = TUYA_ADC_SCAN;
    adc_cfg.width = 10;
    adc_cfg.conv_cnt = 1;

    ret = tkl_adc_init(ADC_NUM_0, &adc_cfg);
    if(ret != OPRT_OK) {
        // failed
        return;
    }

    ret = tkl_adc_read_data(ADC_NUM_0, adc_value, ADC_CHANNEL_NUM);
    if(ret != OPRT_OK) {
        // failed
        return;
    }

    // Output the values of adc_value[ADC_CHANNEL_NUM]

    ret = tkl_adc_deinit(ADC_NUM_0);
    if(ret != OPRT_OK) {
        // failed
        return;
    }
}