Osamu Koizumi
Device driver for AD converters MCP3426, MCP3427, and MCP3428.
Diff: mcp342x.h
- Revision:
- 2:96d9bfe25b03
- Parent:
- 1:bc877c37027c
--- a/mcp342x.h Fri Apr 29 23:53:18 2016 +0000
+++ b/mcp342x.h Thu May 05 17:55:23 2016 +0000
@@ -3,6 +3,70 @@
#include "mbed.h"
+/**
+ * Device driver for MCP3426, MCP3427, and MCP3428.
+ * @note MCP342x is Analog-to-Digital Converter (ADC) IC with I2C interface.
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "mcp342x.h"
+ *
+ * #define I2C_SPEED_100KHZ 100000
+ * #define I2C_SPEED_400KHZ 400000
+ * #define PIN_SERIAL_TX P0_4
+ * #define PIN_SERIAL_RX P0_5
+ *
+ * int16_t getAdcData(MCP342X *mcp3428, MCP342X::AdcChannel ch, MCP342X::SampleSetting s) {
+ * // Configure channel and trigger.
+ * mcp3428->setChannel(ch);
+ * mcp3428->setSampleSetting(s);
+ * mcp3428->trigger();
+ *
+ * // polling data
+ * MCP342X::Data data;
+ * do {
+ * wait_ms(WAIT_ADC_MS);
+ * mcp3428->getData(&data);
+ * } while(data.st == MCP342X::DATA_NOT_UPDATED);
+ *
+ * return data.value;
+ * }
+ *
+ * int main(void) {
+ * // Instanciate I2C
+ * I2C i2c(I2C_SDA0, I2C_SCL0);
+ * i2c.frequency(I2C_SPEED_400KHZ);
+ *
+ * // Serial output for debug. (optional)
+ * Serial serial(PIN_SERIAL_TX, PIN_SERIAL_RX);
+ *
+ * // Instanciate MCP342x
+ * // Suppose that the slave address of MCP342x on your board is .
+ * MCP342X mcp342x(&i2c, MCP342X::SLAVE_ADDRESS_68H);
+ *
+ * // Sets MCP342x one-shot measurement mode.
+ * mcp342x.setSampleSetting(MCP342X::ONE_SHOT);
+ *
+ * while(true) {
+ * // Supposes that the device is MCP3428, which has 4 channels.
+ * const uint8_t CHANNEL_NUM = 4;
+ * // Sampling setting. Ch1 is 12-bit, Ch2 is 14-bit, Ch3 is 16-bit, Ch4 is 16-bit.
+ * const MCP342X::SampleSetting sampleSetting[CHANNEL_NUM] =
+ * {MCP342X::SAMPLE_240HZ_12BIT, MCP342X::SAMPLE_60HZ_14BIT,
+ * MCP342X::SAMPLE_15HZ_16BIT, MCP342X::SAMPLE_15HZ_16BIT};
+ * // Data buffer.
+ * int16_t data[CHANNEL_NUM];
+ * // Measures each channel.
+ * for (int i=0; i < CHANNEL_NUM; i++) {
+ * mcp342x.getAdcData(&data[i], (MCP342X::AdcChannel)i, sampleSetting[i]);
+ * }
+ * // Prints out the ADC results.
+ * serial.printf("%d, %d, %d, %d\r\n", data[0], data[1], data[2], data[3]);
+ * }
+ * }
+ * @endcode
+ */
class MCP342X
{
public:
@@ -10,14 +74,14 @@
* Slave addresses.
*/
typedef enum {
- SLAVE_ADDRESS_68H, /**< When Adr0 pin = L and Adr1 pin = L, or Adr0 pin = float and Adr1 pin = float. */
- SLAVE_ADDRESS_69H, /**< When Adr0 pin = L and Adr1 pin = float. */
- SLAVE_ADDRESS_6AH, /**< When Adr0 pin = L and Adr1 pin = H. */
- SLAVE_ADDRESS_6CH, /**< When Adr0 pin = H and Adr1 pin = L. */
- SLAVE_ADDRESS_6DH, /**< When Adr0 pin = H and Adr1 pin = float. */
- SLAVE_ADDRESS_6EH, /**< When Adr0 pin = H and Adr1 pin = H. */
- SLAVE_ADDRESS_6BH, /**< When Adr0 pin = float and Adr1 pin = L. */
- SLAVE_ADDRESS_6FH, /**< When Adr0 pin = float and Adr1 pin = H. */
+ SLAVE_ADDRESS_68H = 0x68, /**< When Adr0 pin = L and Adr1 pin = L, or Adr0 pin = float and Adr1 pin = float. */
+ SLAVE_ADDRESS_69H = 0x69, /**< When Adr0 pin = L and Adr1 pin = float. */
+ SLAVE_ADDRESS_6AH = 0x6A, /**< When Adr0 pin = L and Adr1 pin = H. */
+ SLAVE_ADDRESS_6CH = 0x6C, /**< When Adr0 pin = H and Adr1 pin = L. */
+ SLAVE_ADDRESS_6DH = 0x6D, /**< When Adr0 pin = H and Adr1 pin = float. */
+ SLAVE_ADDRESS_6EH = 0x6E, /**< When Adr0 pin = H and Adr1 pin = H. */
+ SLAVE_ADDRESS_6BH = 0x6B, /**< When Adr0 pin = float and Adr1 pin = L. */
+ SLAVE_ADDRESS_6FH = 0x6F, /**< When Adr0 pin = float and Adr1 pin = H. */
} SlaveAddress;
/**
@@ -68,10 +132,10 @@
* ADC channel selection.
*/
typedef enum {
- ADC_CH1, /**< Channel 1, default. */
- ADC_CH2, /**< Channel 2 */
- ADC_CH3, /**< Channel 3, MCP3428 only, treated as channel 1 by the MCP3426/MCP3427. */
- ADC_CH4, /**< Channel 4, MCP3428 only, treated as channel 2 by the MCP3426/MCP3427. */
+ ADC_CH1 = 0, /**< Channel 1, default. */
+ ADC_CH2 = 1, /**< Channel 2 */
+ ADC_CH3 = 2, /**< Channel 3, MCP3428 only, treated as channel 1 by the MCP3426/MCP3427. */
+ ADC_CH4 = 3, /**< Channel 4, MCP3428 only, treated as channel 2 by the MCP3426/MCP3427. */
} AdcChannel;
/**
@@ -85,18 +149,18 @@
} PgaSetting;
/**
- * AD result data.
+ * ADC result.
*/
typedef struct {
DataStatus st;
- int16_t value;
+ int16_t value; /**< ADC value. The value takes from -2^11 to (2^11 - 1) when 12 bit sample mode, from -2^13 to (2^13 - 1) when 14 bit sample mode, from -2^15 to (2^15 - 1) when 16bit sample mode. */
} Data;
/**
* Constructor.
*
- * @param conn instance of I2C
- * @param addr slave address of the device
+ * @param conn Pointer to an instance of I2C.
+ * @param addr Slave address of the device.
*/
MCP342X(I2C *conn, SlaveAddress addr);
@@ -127,7 +191,7 @@
ConversionMode getConversionMode();
/**
- * Sets sample setting.
+ * Sets sample setting, i.e. sampling frequency and resolution bits.
* @param s Sample setting to be set.
* @return SUCCESS when succeeded. Other value will be returned when error.
*/
@@ -140,14 +204,14 @@
SampleSetting getSampleSetting();
/**
- * Sets gain of Programmable Gain Amplifier (PGA).
+ * Sets the gain of Programmable Gain Amplifier (PGA).
* @param s PGA seeting to be set.
* @return SUCCESS when succeeded. Other value will be returned when error.
*/
Status setPgaSetting(PgaSetting s);
/**
- * Gets the current PGA setting.
+ * Gets the current Programmable Gain Amplifier (PGA) setting.
* @return Current PGA setting.
*/
PgaSetting getPgaSetting();
@@ -159,17 +223,11 @@
Status getData(Data *pt);
/**
- * Trigger AD conversion.
+ * Trigger AD conversion. In continuous measurement mode, this function has no effect.
* @return SUCCESS when succeeded. Other value will be returned when error.
*/
Status trigger();
- /**
- * Gets the data conversion time.
- * @return Conversion time based on the current sample setting in milli-second unit.
- */
- float getDataConversionTime();
-
private:
typedef struct {
MeasurementTrigger measurementTrigger;