ADS1115.h

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#ifndef ADS1115_H
#define ADS1115_H
 
#include "sys/i2c.h"
 
class ADS1115 : I2C::Device {
private:
    enum {
        CONVERSION,
        CONFIG,
        LO_THRESH,
        HI_THRESH
    };
 
    const double uV[6] = {
        187.5,
        125,
        62.5,
        31.25,
        15.625,
        7.8125
    };
 
public:
    enum range {
        FS6144,
        FS4096,
        FS2048,
        FS1024,
        FS0512,
        FS0256
    } eFullScale = FS2048;      
 
    enum dataRate {
        SPS8,
        SPS16,
        SPS32,
        SPS64,
        SPS128,
        SPS250,
        SPS475,
        SPS860
    } eDataRate = SPS128;       
 
    enum mux {
        AIN0_1,
        AIN0_3,
        AIN1_3,
        AIN2_3,
        AIN0,
        AIN1,
        AIN2,
        AIN3
    } eMux = AIN0_1;            
 
    // single conversion mode
    bool single = false;
    bool cMod = false;
    bool cPol = false;
    bool cLat = false;
    uint8_t cQue = 0;
 
    ADS1115(Sink<I2C::Request> &bus,
            uint8_t address = 0b1001000, enum range fs = FS6144,
            enum dataRate dr = SPS64, enum mux mx = AIN0):
                I2C::Device(bus, address), eFullScale(fs),
                eDataRate(dr), eMux(mx) {
        updateConfig();
    }
 
    void updateConfig() {
        write(CONFIG, 0 << 15 |
                eMux << 12 |
                eFullScale << 9 |
                (single & 1) << 8 |
                eDataRate << 5 |
                (cMod & 1) << 4 |
                (cPol & 1) << 3 |
                (cLat & 1) << 2 |
                cQue
                );
        setPointer(CONVERSION);
    }
 
    void measure() {
        read();
    }
 
    double volts() {
        return adc;
    }
 
private:
    void callback(const I2C::Request &rq) override {
        if (rq.data.size != 2) return;
        adc = (int16_t)(rq.data[0]<<8 | rq.data[1]) * uV[eFullScale] * 1e-6;
    }
    double adc{0};
    void setPointer(uint8_t reg) {
        bus.trypush({
            .dev = this,
            .data = {reg},
        });
    }
 
    void read() {
        bus.trypush({
            .dev = this,
            .data = 2,
            .opts = {
                .read = true,
                },
            });
    }
 
    void write(uint8_t reg, uint16_t val) {
        bus.trypush({
            .dev = this,
            .data = {reg, (uint8_t)(val>>8), (uint8_t)val},
            });
    }
};
 
#endif //ADS1115_H