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MAX30100 pulse rate sensor
MAX30100.h
- Committer:
- kohlerba
- Date:
- 2017-08-18
- Revision:
- 1:0c2135629097
- Parent:
- 0:faf977308bdc
- Child:
- 2:d329886938f1
File content as of revision 1:0c2135629097:
#ifndef MAX30100_H #define MAX30100_H #include "mbed.h" //definitions #define MAX30100_ADDRESS 0x57 // Registers #define MAX30100_INT_STATUS 0x00 // Which interrupts are tripped #define MAX30100_INT_ENABLE 0x01 // Which interrupts are active #define MAX30100_FIFO_WR_PTR 0x02 // Where data is being written #define MAX30100_OVRFLOW_CTR 0x03 // Number of lost samples #define MAX30100_FIFO_RD_PTR 0x04 // Where to read from #define MAX30100_FIFO_DATA 0x05 // Ouput data buffer #define MAX30100_MODE_CONFIG 0x06 // Control register #define MAX30100_SPO2_CONFIG 0x07 // Oximetry settings #define MAX30100_LED_CONFIG 0x09 // Pulse width and power of LEDs #define MAX30100_TEMP_INTG 0x16 // Temperature value, whole number #define MAX30100_TEMP_FRAC 0x17 // Temperature value, fraction #define MAX30100_REV_ID 0xFE // Part revision #define MAX30100_PART_ID 0xFF // Part ID, normally 0x11 typedef enum{ // This is the same for both LEDs pw200, // 200us pulse pw400, // 400us pulse pw800, // 800us pulse pw1600 // 1600us pulse }pulseWidth; typedef enum{ sr50, // 50 samples per second sr100, // 100 samples per second sr167, // 167 samples per second sr200, // 200 samples per second sr400, // 400 samples per second sr600, // 600 samples per second sr800, // 800 samples per second sr1000 // 1000 samples per second }sampleRate; typedef enum{ i0, // No current i4, // 4.4mA i8, // 7.6mA i11, // 11.0mA i14, // 14.2mA i17, // 17.4mA i21, // 20.8mA i27, // 27.1mA i31, // 30.6mA i34, // 33.8mA i37, // 37.0mA i40, // 40.2mA i44, // 43.6mA i47, // 46.8mA i50 // 50.0mA }ledCurrent; //Set up I2C, (SDA,SCL) I2C i2c(I2C_SDA, I2C_SCL); uint16_t IR = 0; // Last IR reflectance datapoint uint16_t RED = 0; // Last Red reflectance datapoint class MAX30100 { protected: public: void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) { char data_write[2]; data_write[0] = subAddress; data_write[1] = data; i2c.write(address, data_write, 2, 0); } char readByte(uint8_t address, uint8_t subAddress) { char data[1]; // `data` will store the register data char data_write[1]; data_write[0] = subAddress; i2c.write(address, data_write, 1, 1); // no stop i2c.read(address, data, 1, 0); return data[0]; } void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) { char data[14]; char data_write[1]; data_write[0] = subAddress; i2c.write(address, data_write, 1, 1); // no stop i2c.read(address, data, count, 0); for(int ii = 0; ii < count; ii++) { dest[ii] = data[ii]; } } void setLEDs(pulseWidth pw, ledCurrent red, ledCurrent ir){ uint8_t reg = readByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG); reg = reg & 0xFC; // Set LED_PW to 00 writeByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG, reg | pw); // Mask LED_PW writeByte(MAX30100_ADDRESS, MAX30100_LED_CONFIG, (red<<4) | ir); // write LED configs } void setSPO2(sampleRate sr){ uint8_t reg = readByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG); reg = reg & 0xE3; // Set SPO2_SR to 000 writeByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG, reg | (sr<<2)); // Mask SPO2_SR reg = readByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG); reg = reg & 0xf8; // Set Mode to 000 writeByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG, reg | 0x03); // Mask MODE } int getNumSamp(void){ uint8_t wrPtr = readByte(MAX30100_ADDRESS, MAX30100_FIFO_WR_PTR); uint8_t rdPtr = readByte(MAX30100_ADDRESS, MAX30100_FIFO_RD_PTR); return (abs( 16 + wrPtr - rdPtr ) % 16); } void readSensor(void){ uint8_t temp[4] = {0}; // Temporary buffer for read values readBytes(MAX30100_ADDRESS, MAX30100_FIFO_DATA, 4, &temp[0]); // Read four times from the FIFO IR = (temp[0]<<8) | temp[1]; // Combine values to get the actual number RED = (temp[2]<<8) | temp[3]; // Combine values to get the actual number } void shutdown(void){ uint8_t reg = readByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG); // Get the current register writeByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG, reg | 0x80); // mask the SHDN bit } void reset(void){ uint8_t reg = readByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG); // Get the current register writeByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG, reg | 0x40); // mask the RESET bit } void startup(void){ uint8_t reg = readByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG); // Get the current register writeByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG, reg & 0x7F); // mask the SHDN bit } int getRevID(void){ return readByte(MAX30100_ADDRESS, MAX30100_REV_ID); } int getPartID(void){ return readByte(MAX30100_ADDRESS, MAX30100_PART_ID); } void begin(pulseWidth pw, ledCurrent ir, sampleRate sr){ writeByte(MAX30100_ADDRESS, MAX30100_MODE_CONFIG, 0x02); // Heart rate only writeByte(MAX30100_ADDRESS, MAX30100_LED_CONFIG, ir); writeByte(MAX30100_ADDRESS, MAX30100_SPO2_CONFIG, (sr<<2)|pw); } }; #endif