64 lines
2.3 KiB
C++
64 lines
2.3 KiB
C++
/* Copyright (C) 2012 Kristian Lauszus, TKJ Electronics. All rights reserved.
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This software may be distributed and modified under the terms of the GNU
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General Public License version 2 (GPL2) as published by the Free Software
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Foundation and appearing in the file GPL2.TXT included in the packaging of
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this file. Please note that GPL2 Section 2[b] requires that all works based
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on this software must also be made publicly available under the terms of
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the GPL2 ("Copyleft").
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Contact information
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-------------------
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Kristian Lauszus, TKJ Electronics
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Web : http://www.tkjelectronics.com
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e-mail : kristianl@tkjelectronics.com
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*/
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const uint8_t IMUAddress = 0x68; // AD0 is logic low on the PCB
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const uint16_t I2C_TIMEOUT = 10; // Used to check for errors in I2C communication
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uint8_t i2cWrite(uint8_t registerAddress, uint8_t data, bool sendStop) {
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return i2cWrite(registerAddress, &data, 1, sendStop); // Returns 0 on success
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}
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uint8_t i2cWrite(uint8_t registerAddress, uint8_t *data, uint8_t length, bool sendStop) {
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Wire.beginTransmission(IMUAddress);
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Wire.write(registerAddress);
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Wire.write(data, length);
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uint8_t rcode = Wire.endTransmission(sendStop); // Returns 0 on success
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if (rcode) {
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Serial.print(F("i2cWrite failed: "));
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Serial.println(rcode);
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}
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return rcode; // See: http://arduino.cc/en/Reference/WireEndTransmission
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}
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uint8_t i2cRead(uint8_t registerAddress, uint8_t *data, uint8_t nbytes) {
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uint32_t timeOutTimer;
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Wire.beginTransmission(IMUAddress);
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Wire.write(registerAddress);
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uint8_t rcode = Wire.endTransmission(false); // Don't release the bus
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if (rcode) {
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Serial.print(F("i2cRead failed: "));
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Serial.println(rcode);
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return rcode; // See: http://arduino.cc/en/Reference/WireEndTransmission
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}
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Wire.requestFrom(IMUAddress, nbytes, (uint8_t)true); // Send a repeated start and then release the bus after reading
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for (uint8_t i = 0; i < nbytes; i++) {
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if (Wire.available())
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data[i] = Wire.read();
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else {
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timeOutTimer = micros();
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while (((micros() - timeOutTimer) < I2C_TIMEOUT) && !Wire.available());
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if (Wire.available())
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data[i] = Wire.read();
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else {
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Serial.println(F("i2cRead timeout"));
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return 5; // This error value is not already taken by endTransmission
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}
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}
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}
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return 0; // Success
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}
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