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明石高専ロボ研 mbedライブラリ
Dependents: MDD_L432KC USB2RS485 pathtracking odometry ... more
Diff: lidar_lite.cpp
- Revision:
- 6:678c6b604ac7
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lidar_lite.cpp Thu Nov 12 16:44:10 2020 +0000 @@ -0,0 +1,317 @@ +#include "lidar_lite.h" + +LIDARLite::LIDARLite(I2C &i2c):i2c_(i2c){} + +/*------------------------------------------------------------------------------ + Begin + Starts the sensor and I2C. + Parameters + ------------------------------------------------------------------------------ + configuration: Default 0. Selects one of several preset configurations. + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::begin(int configuration, char lidarliteAddress) +{ + configure(configuration, lidarliteAddress); // Configuration settings +} /* LIDARLite::begin */ + +/*------------------------------------------------------------------------------ + Configure + Selects one of several preset configurations. + Parameters + ------------------------------------------------------------------------------ + configuration: Default 0. + 0: Default mode, balanced performance. + 1: Short range, high speed. Uses 0x1d maximum acquisition count. + 2: Default range, higher speed short range. Turns on quick termination + detection for faster measurements at short range (with decreased + accuracy) + 3: Maximum range. Uses 0xff maximum acquisition count. + 4: High sensitivity detection. Overrides default valid measurement detection + algorithm, and uses a threshold value for high sensitivity and noise. + 5: Low sensitivity detection. Overrides default valid measurement detection + algorithm, and uses a threshold value for low sensitivity and noise. + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::configure(int configuration, char lidarliteAddress) +{ + switch (configuration) + { + case 0: // Default mode, balanced performance + write(0x02,0x80,lidarliteAddress); // Default + write(0x04,0x08,lidarliteAddress); // Default + write(0x1c,0x00,lidarliteAddress); // Default + break; + + case 1: // Short range, high speed + write(0x02,0x1d,lidarliteAddress); + write(0x04,0x08,lidarliteAddress); // Default + write(0x1c,0x00,lidarliteAddress); // Default + break; + + case 2: // Default range, higher speed short range + write(0x02,0x80,lidarliteAddress); // Default + write(0x04,0x00,lidarliteAddress); + write(0x1c,0x00,lidarliteAddress); // Default + break; + + case 3: // Maximum range + write(0x02,0xff,lidarliteAddress); + write(0x04,0x08,lidarliteAddress); // Default + write(0x1c,0x00,lidarliteAddress); // Default + break; + + case 4: // High sensitivity detection, high erroneous measurements + write(0x02,0x80,lidarliteAddress); // Default + write(0x04,0x08,lidarliteAddress); // Default + write(0x1c,0x80,lidarliteAddress); + break; + + case 5: // Low sensitivity detection, low erroneous measurements + write(0x02,0x80,lidarliteAddress); // Default + write(0x04,0x08,lidarliteAddress); // Default + write(0x1c,0xb0,lidarliteAddress); + break; + } +} /* LIDARLite::configure */ + +/*------------------------------------------------------------------------------ + Set I2C Address + Set Alternate I2C Device Address. See Operation Manual for additional info. + Parameters + ------------------------------------------------------------------------------ + newAddress: desired secondary I2C device address + disableDefault: a non-zero value here means the default 0x62 I2C device + address will be disabled. + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::setI2Caddr(char newAddress, bool disableDefault, char lidarliteAddress) +{ + char dataBytes[2]; + + // Read UNIT_ID serial number bytes and write them into I2C_ID byte locations + read ((0x16 | 0x80), 2, dataBytes, false, lidarliteAddress); + write(0x18, dataBytes[0], lidarliteAddress); + write(0x19, dataBytes[1], lidarliteAddress); + + // Write the new I2C device address to registers + dataBytes[0] = newAddress; + write(0x1a, dataBytes[0], lidarliteAddress); + + // Enable the new I2C device address using the default I2C device address + dataBytes[0] = 0; + write(0x1e, dataBytes[0], lidarliteAddress); + + // If desired, disable default I2C device address (using the new I2C device address) + if (disableDefault) + { + dataBytes[0] = (1 << 3); // set bit to disable default address + write(0x1e, dataBytes[0], newAddress); + } +} /* LIDARLite::setI2Caddr */ + +/*------------------------------------------------------------------------------ + Reset + Reset device. The device reloads default register settings, including the + default I2C address. Re-initialization takes approximately 22ms. + Parameters + ------------------------------------------------------------------------------ + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::reset( char lidarliteAddress) +{ + write(0x00,0x00,lidarliteAddress); +} /* LIDARLite::reset */ + +/*------------------------------------------------------------------------------ + Distance + Take a distance measurement and read the result. + Process + ------------------------------------------------------------------------------ + 1. Write 0x04 or 0x03 to register 0x00 to initiate an aquisition. + 2. Read register 0x01 (this is handled in the read() command) + - if the first bit is "1" then the sensor is busy, loop until the first + bit is "0" + - if the first bit is "0" then the sensor is ready + 3. Read two bytes from register 0x8f and save + 4. Shift the first value from 0x8f << 8 and add to second value from 0x8f. + The result is the measured distance in centimeters. + Parameters + ------------------------------------------------------------------------------ + biasCorrection: Default true. Take aquisition with receiver bias + correction. If set to false measurements will be faster. Receiver bias + correction must be performed periodically. (e.g. 1 out of every 100 + readings). + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +int LIDARLite::distance(bool biasCorrection, char lidarliteAddress) +{ + if(biasCorrection) + { + // Take acquisition & correlation processing with receiver bias correction + write(0x00,0x04,lidarliteAddress); + } + else + { + // Take acquisition & correlation processing without receiver bias correction + write(0x00,0x03,lidarliteAddress); + } + // Array to store high and low bytes of distance + char distanceArray[2]; + // Read two bytes from register 0x8f (autoincrement for reading 0x0f and 0x10) + read(0x8f,2,distanceArray,true,lidarliteAddress);//0x8f + // Shift high byte and add to low byte + int distance = (distanceArray[0] << 8) + distanceArray[1]; + return(distance); +} /* LIDARLite::distance */ + +/*------------------------------------------------------------------------------ + Write + Perform I2C write to device. + Parameters + ------------------------------------------------------------------------------ + myAddress: register address to write to. + myValue: value to write. + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::write(char myAddress, char myValue, char lidarliteAddress) +{ + char data[2] = {myAddress,myValue};//register value + int nackCatcher = i2c_.write((int)lidarliteAddress,data,2); + // A nack means the device is not responding, report the error over serial + /* + if(nackCatcher != 0) + { + //printf("> nack"); + }*/ + + //wait_ms(1); // 1 ms delay for robustness with successive reads and writes +} /* LIDARLite::write */ + +/*------------------------------------------------------------------------------ + Read + Perform I2C read from device. Will detect an unresponsive device and report + the error over serial. The optional busy flag monitoring + can be used to read registers that are updated at the end of a distance + measurement to obtain the new data. + Parameters + ------------------------------------------------------------------------------ + myAddress: register address to read from. + numOfBytes: numbers of bytes to read. Can be 1 or 2. + arrayToSave: an array to store the read values. + monitorBusyFlag: if true, the routine will repeatedly read the status + register until the busy flag (LSB) is 0. +------------------------------------------------------------------------------*/ +void LIDARLite::read(char myAddress, int numOfBytes, char arrayToSave[2], bool monitorBusyFlag, char lidarliteAddress) +{ + char data; + int busyFlag = 0; // busyFlag monitors when the device is done with a measurement + bool errer_flag =false; + if(monitorBusyFlag) + { + busyFlag = 1; // Begin read immediately if not monitoring busy flag + } + int busyCounter = 0; // busyCounter counts number of times busy flag is checked, for timeout + + while(busyFlag != 0) // Loop until device is not busy + { + // Read status register to check busy flag + data = 0x01;//Set the status register to be read + int nackCatcher = i2c_.write(lidarliteAddress,&data,1,true); + // A nack means the device is not responding, report the error over serial + if(nackCatcher != 0) + { + //printf("> nack"); + } + + i2c_.read(lidarliteAddress,&data,1); // Read register 0x01 + busyFlag = data & 0x1; // Assign the LSB of the status register to busyFlag + + busyCounter++; // Increment busyCounter for timeout + + // Handle timeout condition, exit while loop and goto bailout + if(busyCounter > 9999) + { + errer_flag = true; + break; + } + } + + // Device is not busy, begin read + if(busyFlag == 0 && !errer_flag) + { + data = myAddress;// Set the register to be read + int nackCatcher = i2c_.write(lidarliteAddress,&data,1,true); + // A nack means the device is not responding, report the error over serial + if(nackCatcher != 0) + { + //printf("> nack"); + } + + // Perform read of 1 or 2 bytes, save in arrayToSave + i2c_.read(lidarliteAddress, arrayToSave, numOfBytes); + } + + // bailout reports error over serial + if(busyCounter > 9999 || errer_flag) + { + busyCounter = 0; + //printf("> read failed"); + } +} /* LIDARLite::read */ + +/*------------------------------------------------------------------------------ + Correlation Record To Serial + The correlation record used to calculate distance can be read from the device. + It has a bipolar wave shape, transitioning from a positive going portion to a + roughly symmetrical negative going pulse. The point where the signal crosses + zero represents the effective delay for the reference and return signals. + Process + ------------------------------------------------------------------------------ + 1. Take a distance reading (there is no correlation record without at least + one distance reading being taken) + 2. Select memory bank by writing 0xc0 to register 0x5d + 3. Set test mode select by writing 0x07 to register 0x40 + 4. For as many readings as you want to take (max is 1024) + 1. Read two bytes from 0xd2 + 2. The Low byte is the value from the record + 3. The high byte is the sign from the record + Parameters + ------------------------------------------------------------------------------ + separator: the separator between serial data words + numberOfReadings: Default: 256. Maximum of 1024 + lidarliteAddress: Default 0x62. Fill in new address here if changed. See + operating manual for instructions. +------------------------------------------------------------------------------*/ +void LIDARLite::correlationRecordToSerial(char separator, int numberOfReadings, char lidarliteAddress) +{ + + // Array to store read values + char correlationArray[2]; + // Var to store value of correlation record + int correlationValue = 0; + // Selects memory bank + write(0x5d,0xc0,lidarliteAddress); + // Test mode enable + write(0x40, 0x07,lidarliteAddress); + for(int i = 0; i<numberOfReadings; i++){ + // Select single byte + read(0xd2,2,correlationArray,false,lidarliteAddress); + // Low byte is the value of the correlation record + correlationValue = correlationArray[0]; + // if upper byte lsb is set, the value is negative + if((int)correlationArray[1] == 1){ + correlationValue |= 0xff00; + } + //printf((int)correlationValue); + //printf(separator); + } + // test mode disable + write(0x40,0x00,lidarliteAddress); +} /* LIDARLite::correlationRecordToSerial */ \ No newline at end of file