nymea-plugins-modbus/unipi/mcp342xchannel.cpp

88 lines
3.2 KiB
C++

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* GNU Lesser General Public License Usage
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#include "mcp342xchannel.h"
#include "extern-plugininfo.h"
#include <unistd.h>
#define GENERAL_CALL_RESET 0x0006
#define GENERAL_CALL_LATCH 0x0004
#define GENERAL_CALL_CONVERSION 0x0008
#define CONFIGURATION_REGISTER
MCP342XChannel::MCP342XChannel(const QString &portName, int address, int channel, Gain gain, QObject *parent) :
I2CDevice(portName, address, parent),
m_channel(channel),
m_gain(gain)
{
}
QByteArray MCP342XChannel::readData(int fd)
{
// Wair for previous messurements to be completed
char readBuf[3] = {0};
do {
if (read(fd, readBuf, 3) != 3) {
qCWarning(dcUniPi()) << "MCP342X: could not read ADC data";
return QByteArray();
}
} while (!(readBuf[2] & (1 << ConfRegisterBits::RDY)));
// Start a configuration conversation
unsigned char writeBuf[1] = {0};
writeBuf[0] |= (m_channel & 0x0003) << ConfRegisterBits::C0;
writeBuf[0] |= m_gain << ConfRegisterBits::G0;
//writeBuf[0] |= SampleRateSelectionBit::Bits18 << ConfRegisterBits::S0;
writeBuf[0] |= 1 << ConfRegisterBits::OC; // one shot
writeBuf[0] |= 1 << ConfRegisterBits::RDY; // start conversoin
if (write(fd, writeBuf, 1) != 1) {
qCWarning(dcUniPi()) << "MCP342X: could not write config register";
return QByteArray();
}
// Wait again for the device to finish measurement
do {
if (read(fd, readBuf, 3) != 3) {
qCWarning(dcUniPi()) << "MCP342X: could not read ADC data";
return QByteArray();
}
} while (!(readBuf[2] & (1 << ConfRegisterBits::RDY)));
if ((readBuf[2] & (0x03 << ConfRegisterBits::C0)) != ((m_channel & 0x0003) << ConfRegisterBits::C0))
return QByteArray();
return QByteArray(readBuf, 3);
}