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sns: amend ADS1X115 I2CPort to use common gain & datarate settings
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ref. #1033, this could be used as-is with a generic analog sensor code
by substituting ::analogRead(channel) with I2CPort::read(channel)
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@mcspr
mcspr committed Jun 22, 2021
1 parent bacff31 commit c056c54
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Showing 3 changed files with 64 additions and 68 deletions.
4 changes: 4 additions & 0 deletions code/espurna/config/sensors.h
View file
Expand Up @@ -488,6 +488,10 @@
#define EMON_ADS1X15_GAIN ADS1X15_REG_CONFIG_PGA_4_096V
#endif

#ifndef EMON_ADS1X15_DATARATE
#define EMON_ADS1X15_DATARATE ADS1X15_REG_CONFIG_DR_MASK
#endif

#ifndef EMON_ADS1X15_MASK
#define EMON_ADS1X15_MASK 0x0F // A0=1 aka 0b1
// A1=2 aka 0b10
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5 changes: 2 additions & 3 deletions code/espurna/sensor.cpp
View file
Expand Up @@ -1868,7 +1868,8 @@ void _sensorLoad() {

#if EMON_ADS1X15_SUPPORT
{
auto port = std::make_shared<EmonADS1X15Sensor::I2CPort>(EMON_ADS1X15_I2C_ADDRESS, EMON_ADS1X15_TYPE);
auto port = std::make_shared<EmonADS1X15Sensor::I2CPort>(
EMON_ADS1X15_I2C_ADDRESS, EMON_ADS1X15_TYPE, EMON_ADS1X15_GAIN, EMON_ADS1X15_DATARATE);

unsigned char channel { 0 };
unsigned char mask { EMON_ADS1X15_MASK };
Expand All @@ -1877,9 +1878,7 @@ void _sensorLoad() {
while (mask) {
if (mask & FirstBit) {
auto* sensor = new EmonADS1X15Sensor(port);
sensor->setGain(EMON_ADS1X15_GAIN);
sensor->setVoltage(EMON_MAINS_VOLTAGE);
sensor->setReferenceVoltage(EMON_REFERENCE_VOLTAGE);
sensor->setChannel(channel);
_sensors.push_back(sensor);
}
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123 changes: 58 additions & 65 deletions code/espurna/sensors/EmonADS1X15Sensor.h
View file
Expand Up @@ -105,9 +105,11 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {
public:
I2CPort() = default;

explicit I2CPort(uint8_t address, uint8_t type) :
explicit I2CPort(uint8_t address, uint8_t type, uint16_t gain, uint16_t datarate) :
_address(address),
_type(type)
_type(type),
_gain(gain),
_datarate(datarate)
{}

bool lock(uint8_t address) {
Expand All @@ -127,26 +129,66 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {
return _type;
}

template <typename T>
unsigned int read(T& sensor) {
if (_channel != sensor._channel) {
sensor.config(sensor._channel, true, false);
sensor.config(sensor._channel, false, false);
sensor.config(sensor._channel, false, true);
void config(unsigned char channel, bool continuous, bool start) {
// Start with default values
uint16_t config = 0;
config |= _gain; // Set PGA/voltage range (0x0200)
config |= _datarate; // Default is at max speed (0x00E0)
//config |= ADS1X15_REG_CONFIG_CMODE_TRAD; // Traditional comparator (default val) (0x0000)
//config |= ADS1X15_REG_CONFIG_CPOL_ACTVLOW; // Alert/Rdy active low (default val) (0x0000)
//config |= ADS1X15_REG_CONFIG_CLAT_NONLAT; // Non-latching (default val) (0x0000)
config |= ADS1X15_REG_CONFIG_CQUE_NONE; // Disable the comparator (default val) (0x0003)
if (start) {
config |= ADS1X15_REG_CONFIG_OS_SINGLE; // Start a single-conversion (0x8000)
}
if (continuous) {
//config |= ADS1X15_REG_CONFIG_MODE_CONTIN; // Continuous mode (default) (0x0000)
} else {
config |= ADS1X15_REG_CONFIG_MODE_SINGLE; // Single-shot mode (0x0100)
}
config |= ((channel + 4) << 12); // Set single-ended input channel (0x4000 - 0x7000)

// Write config register to the ADC
i2c_write_uint16(_sensor_address.address(), ADS1X15_REG_POINTER_CONFIG, config);
}

uint16_t gain() const {
return _gain;
}

unsigned int read(unsigned char channel) {
// Make sure we configure the correct channel for reading
// Force stop by setting single mode and back to continuous
// (as we can't read from all channels at once)
if (_channel != channel) {
_channel = channel;
config(_channel, true, false);
config(_channel, false, false);
config(_channel, false, true);
nice_delay(10);
sensor.read();
_channel = sensor._channel;
read();
}
sensor.config(_channel, true, true);

return sensor.read();
config(_channel, true, true);

return read();
}

unsigned int read() {
unsigned int value = i2c_read_uint16(_sensor_address.address(), ADS1X15_REG_POINTER_CONVERT);
if (_type == ADS1X15_CHIP_ADS1015) {
value >>= ADS1015_BIT_SHIFT;
}
delayMicroseconds(500);
return value;
}

private:
I2CSensorAddress _sensor_address;
uint8_t _channel { 0xff };
uint8_t _address { 0x00 };
uint8_t _type { ADS1X15_CHIP_ADS1115 };
uint16_t _gain { ADS1X15_REG_CONFIG_PGA_4_096V };
uint16_t _datarate { ADS1X15_REG_CONFIG_DR_MASK };
};

friend class I2CPort;
Expand All @@ -161,17 +203,6 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {

// ---------------------------------------------------------------------

void setGain(uint16_t gain) {
if (_gain != gain) {
_gain = gain;
_dirty = true;
}
}

uint16_t getGain() {
return _gain;
}

void setChannel(unsigned char channel) {
if ((_channel != channel) && (channel < 4)) {
_channel = channel;
Expand All @@ -182,7 +213,7 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------

// Initialization method, must be idempotent
void begin() override {
if (!_dirty) {
Expand All @@ -195,7 +226,7 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {
}

setResolution(ADS1X15_RESOLUTION);
setReferenceVoltage(gainToReference(_gain));
setReferenceVoltage(gainToReference(_port->gain()));
BaseAnalogEmonSensor::begin();
BaseAnalogEmonSensor::sampleCurrent();

Expand Down Expand Up @@ -232,46 +263,10 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {
}

unsigned int analogRead() override {
return _port->read(*this);
return _port->read(_channel);
}

private:
unsigned int read() {
unsigned int value = i2c_read_uint16(_port->address(), ADS1X15_REG_POINTER_CONVERT);
if (_port->type() == ADS1X15_CHIP_ADS1015) {
value >>= ADS1015_BIT_SHIFT;
}
delayMicroseconds(500);
return value;
}

// Make sure we configure the correct channel for reading
// Force stop by setting single mode and back to continuous
// (as we can't read from all channels at once)

void config(unsigned char channel, bool continuous, bool start) {
// Start with default values
uint16_t config = 0;
config |= _gain; // Set PGA/voltage range (0x0200)
config |= ADS1X15_REG_CONFIG_DR_MASK; // Always at max speed (0x00E0)
//config |= ADS1X15_REG_CONFIG_CMODE_TRAD; // Traditional comparator (default val) (0x0000)
//config |= ADS1X15_REG_CONFIG_CPOL_ACTVLOW; // Alert/Rdy active low (default val) (0x0000)
//config |= ADS1X15_REG_CONFIG_CLAT_NONLAT; // Non-latching (default val) (0x0000)
config |= ADS1X15_REG_CONFIG_CQUE_NONE; // Disable the comparator (default val) (0x0003)
if (start) {
config |= ADS1X15_REG_CONFIG_OS_SINGLE; // Start a single-conversion (0x8000)
}
if (continuous) {
//config |= ADS1X15_REG_CONFIG_MODE_CONTIN; // Continuous mode (default) (0x0000)
} else {
config |= ADS1X15_REG_CONFIG_MODE_SINGLE; // Single-shot mode (0x0100)
}
config |= ((channel + 4) << 12); // Set single-ended input channel (0x4000 - 0x7000)

// Write config register to the ADC
i2c_write_uint16(_port->address(), ADS1X15_REG_POINTER_CONFIG, config);
}

static double gainToReference(uint16_t gain) {
switch (gain) {
case ADS1X15_REG_CONFIG_PGA_6_144V:
Expand All @@ -293,8 +288,6 @@ class EmonADS1X15Sensor : public SimpleAnalogEmonSensor {

PortPtr _port;
unsigned char _channel { 0 };

uint16_t _gain { EMON_ADS1X15_GAIN };
};

#endif // SENSOR_SUPPORT && EMON_ADS1X15_SUPPORT

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