96 lines
3.8 KiB
C
96 lines
3.8 KiB
C
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// -----------------------------------------------------------------------------
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// Abstract I2C sensor class (other sensor classes extend this class)
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// Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>
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// -----------------------------------------------------------------------------
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#if SENSOR_SUPPORT && ( I2C_SUPPORT || EMON_ANALOG_SUPPORT )
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#if I2C_USE_BRZO
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#define I2C_TRANS_SUCCESS 0 // All i2c commands were executed without errors
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#define I2C_TRANS_ERROR_BUS_NOT_FREE 1 // Bus not free, i.e. either SDA or SCL is low
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#define I2C_TRANS_ERROR_NACK_WRITE 2 // Not ACK ("NACK") by slave during write:
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// Either the slave did not respond to the given slave address; or the slave did not ACK a byte transferred by the master.
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#define I2C_TRANS_ERROR_NACK_READ 4 // Not ACK ("NACK") by slave during read,
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// i.e. slave did not respond to the given slave address
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#define I2C_TRANS_ERROR_CLOCK 8 // Clock Stretching by slave exceeded maximum clock stretching time. Most probably, there is a bus stall now!
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#define I2C_TRANS_ERROR_READ_NULL 16 // Read was called with 0 bytes to be read by the master. Command not sent to the slave, since this could yield to a bus stall
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#define I2C_TRANS_ERROR_TIMEOUT 32 // ACK Polling timeout exceeded
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#else // Wire
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#define I2C_TRANS_SUCCESS 0 // success
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#define I2C_TRANS_ERROR_BUFFER_OVERLOW 1 // data too long to fit in transmit buffer
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#define I2C_TRANS_ERROR_NACK_ADDRESS 2 // received NACK on transmit of address
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#define I2C_TRANS_ERROR_NACK_DATA 3 // received NACK on transmit of data
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#define I2C_TRANS_ERROR_OTHER 4 // other error
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#endif
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#pragma once
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#include "BaseSensor.h"
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class I2CSensor : public BaseSensor {
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public:
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void setAddress(unsigned char address) {
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if (_address == address) return;
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_address = address;
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_dirty = true;
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}
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unsigned char getAddress() {
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return _address;
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}
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// Descriptive name of the slot # index
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String slot(unsigned char index) {
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return description();
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};
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// Address of the sensor (it could be the GPIO or I2C address)
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String address(unsigned char index) {
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char buffer[5];
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snprintf(buffer, sizeof(buffer), "0x%02X", _address);
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return String(buffer);
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}
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protected:
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// Specific for I2C sensors
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unsigned char _begin_i2c(unsigned char address, size_t size, unsigned char * addresses) {
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// If we have already locked this address for this sensor quit
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if ((address > 0) && (address == _previous_address)) {
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return _previous_address;
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}
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// Check if we should release a previously locked address
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if ((_previous_address > 0) && (_previous_address != address)) {
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i2cReleaseLock(_previous_address);
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_previous_address = 0;
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}
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// If requesting a specific address, try to ger a lock to it
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if ((0 < address) && i2cGetLock(address)) {
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_previous_address = address;
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return _previous_address;
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}
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// If everything else fails, perform an auto-discover
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_previous_address = i2cFindAndLock(size, addresses);
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// Flag error
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if (0 == _previous_address) {
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_error = SENSOR_ERROR_I2C;
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}
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return _previous_address;
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}
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unsigned char _previous_address = 0;
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unsigned char _address = 0;
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};
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#endif // SENSOR_SUPPORT && I2C_SUPPORT
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