98 lines
3.4 KiB
C++
98 lines
3.4 KiB
C++
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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*
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* Copyright 2013 - 2020, nymea GmbH
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* Contact: contact@nymea.io
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*
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* This file is part of nymea.
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* This project including source code and documentation is protected by
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* copyright law, and remains the property of nymea GmbH. All rights, including
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* reproduction, publication, editing and translation, are reserved. The use of
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* this project is subject to the terms of a license agreement to be concluded
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* with nymea GmbH in accordance with the terms of use of nymea GmbH, available
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* under https://nymea.io/license
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*
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* GNU Lesser General Public License Usage
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* Alternatively, this project may be redistributed and/or modified under the
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* terms of the GNU Lesser General Public License as published by the Free
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* Software Foundation; version 3. This project is distributed in the hope that
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* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this project. If not, see <https://www.gnu.org/licenses/>.
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*
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* For any further details and any questions please contact us under
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* contact@nymea.io or see our FAQ/Licensing Information on
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* https://nymea.io/license/faq
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*
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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#include "ads1115channel.h"
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#include "extern-plugininfo.h"
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#include <unistd.h>
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#define REGISTER_CONVERSATION 0x00
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#define REGISTER_CONFIG 0x01
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#define OPERATIONAL_STATE_IDLE 0x00
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#define OPERATIONAL_STATE_CONVERSATION 0x80
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#define CONVERSION_MODE_CONTINUOUS 0x00
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#define CONVERSION_MODE_SINGLE 0x40
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#define CHANNEL_MODE_DIFFERENTIAL 0x00
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#define CHANNEL_MODE_SINGLE 0x01
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ADS1115Channel::ADS1115Channel(const QString &portName, int address, int channel, Gain gain, QObject *parent):
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I2CDevice(portName, address, parent),
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m_channel(channel),
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m_gain(gain)
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{
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}
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QByteArray ADS1115Channel::readData(int fd)
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{
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// Start a configuration conversation
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unsigned char writeBuf[3] = {0};
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writeBuf[0] = REGISTER_CONFIG; // Select config register
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writeBuf[1] |= OPERATIONAL_STATE_CONVERSATION; // Set conversation bit
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writeBuf[1] |= CHANNEL_MODE_SINGLE;
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writeBuf[1] |= m_channel << 4;
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writeBuf[1] |= m_gain << 1;
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writeBuf[1] |= CONVERSION_MODE_SINGLE;
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writeBuf[2] = 0x85; // 0b10000101: Data rate: 100, not using comparator
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if (write(fd, writeBuf, 3) != 3) {
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qCWarning(dcI2cDevices()) << "ADS1115: could not write config register";
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return QByteArray();
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}
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// Wait for device to accept configuration (conversation bit is cleared)
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char readBuf[2] = {0};
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do {
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if (read(fd, readBuf, 2) != 2) {
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qCWarning(dcI2cDevices()) << "ADS1115: could not read ADC data";
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return QByteArray();
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}
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} while (!(readBuf[0] & OPERATIONAL_STATE_CONVERSATION));
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// Select conversation register
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writeBuf[0] = REGISTER_CONVERSATION;
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if (write(fd, writeBuf, 1) != 1) {
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qCWarning(dcI2cDevices()) << "ADS1115: could not write select register";
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return QByteArray();
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}
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// Read conversation register
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if (read(fd, readBuf, 2) != 2) {
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qCWarning(dcI2cDevices()) << "ADS1115: could not read ADC data";
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return QByteArray();
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}
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return QByteArray(readBuf, 2);
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}
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