I am using a TFmini LiDAR sensor to measure the height of a platform at about 100Hz (recommended rate) with an Arduino DUE as the micro-controller.
The sensor is hooked up to the TTL serial port 1 (it uses 3.3v TTL), pins 19RX, 18TX, gnd and 5v.
the issue i am experiencing is, often upon start up, the sensor will provide distance measurements of 65535 instead of the usual 0-1200 value range. (even after pressing the reset button a few times after start up)
by looking at the library cpp file, it appears to be some "no header, bad checksum or too many attempts" error.
the problem is fixed by unplugging the 4 pin connector from the sensor and then re-inserting it. then it works fine for a few boot ups, then the problem returns.
it seems like the serial connection is not initialising the sensor properly during start up.
do any of you have any ideas how to ensure a proper connection is made before continuing the code?
links to data sheet and library used:
I, from time to time, will get the 65K error. I used to get the error quite a lot till I soldered the connections and switched to single ping mode.
Here is the h file
/*
Arduino driver for Benewake TFMini time-of-flight distance sensor.
by Peter Jansen (December 11/2017)
This code is open source software in the public domain.
THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
The names of the contributors may not be used to endorse or promote products
derived from this software without specific prior written permission.
*/
#if (ARDUINO >= 100)
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
// Defines
#define TFMINI_BAUDRATE 115200
#define TFMINI_DEBUGMODE 0
// The frame size is nominally 9 characters, but we don't include the first two 0x59's marking the start of the frame
#define TFMINI_FRAME_SIZE 7
// Timeouts
#define TFMINI_MAXBYTESBEFOREHEADER 30
#define TFMINI_MAX_MEASUREMENT_ATTEMPTS 10
// States
#define READY 0
#define ERROR_SERIAL_NOHEADER 1
#define ERROR_SERIAL_BADCHECKSUM 2
#define ERROR_SERIAL_TOOMANYTRIES 3
#define MEASUREMENT_OK 10
//
// Driver Class Definition
//
class TFMini {
public:
TFMini(void);
// Configuration
boolean begin(Stream* _streamPtr);
void setSingleScanMode();
// Data collection
uint16_t getDistance();
uint16_t getRecentSignalStrength();
void externalTrigger();
private:
Stream* streamPtr;
int state;
uint16_t distance;
uint16_t strength;
// Low-level communication
void setStandardOutputMode();
void setConfigMode();
int takeMeasurement();
};
Here is the cpp:
/*
Arduino driver for Benewake TFMini time-of-flight distance sensor.
by Peter Jansen (December 11/2017)
This code is open source software in the public domain.
THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
The names of the contributors may not be used to endorse or promote products
derived from this software without specific prior written permission.
*/
#include "TFMini.h"
// Constructor
TFMini::TFMini() {
// Empty constructor
}
boolean TFMini::begin(Stream* _streamPtr) {
// Store reference to stream/serial object
streamPtr = _streamPtr;
// Clear state
distance = -1;
strength = -1;
state = READY;
// Set standard output mode
setStandardOutputMode();
return true;
}
// Public: The main function to measure distance.
uint16_t TFMini::getDistance() {
int numMeasurementAttempts = 0;
while (takeMeasurement() != 0) {
numMeasurementAttempts += 1;
if (numMeasurementAttempts > TFMINI_MAX_MEASUREMENT_ATTEMPTS) {
Serial.println ("TF Mini error: too many measurement attempts");
Serial.println ("Last error:");
if (state == ERROR_SERIAL_NOHEADER) Serial.println("ERROR_SERIAL_NOHEADER");
if (state == ERROR_SERIAL_BADCHECKSUM) Serial.println("ERROR_SERIAL_BADCHECKSUM");
if (state == ERROR_SERIAL_TOOMANYTRIES) Serial.println("ERROR_SERIAL_TOOMANYTRIES");
// Serial.flush();
state = ERROR_SERIAL_TOOMANYTRIES;
distance = -1;
strength = -1;
return -1;
}
}
if (state == MEASUREMENT_OK) {
return distance;
} else {
return -1;
}
}
// Public: Return the most recent signal strength measuremenet from the TF Mini
uint16_t TFMini::getRecentSignalStrength() {
return strength;
}
// Private: Set the TF Mini into the correct measurement mode
void TFMini::setStandardOutputMode() {
// Set to "standard" output mode (this is found in the debug documents)
streamPtr->write((uint8_t)0x42);
streamPtr->write((uint8_t)0x57);
streamPtr->write((uint8_t)0x02);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x01);
streamPtr->write((uint8_t)0x06);
}
// Set configuration mode
void TFMini::setConfigMode() {
// advanced parameter configuration mode
streamPtr->write((uint8_t)0x42);
streamPtr->write((uint8_t)0x57);
streamPtr->write((uint8_t)0x02);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x01);
streamPtr->write((uint8_t)0x02);
}
// Set single scan mode (external trigger)
void TFMini::setSingleScanMode() {
setConfigMode();
// setting trigger source to external
streamPtr->write((uint8_t)0x42);
streamPtr->write((uint8_t)0x57);
streamPtr->write((uint8_t)0x02);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x40);
}
// Send external trigger
void TFMini::externalTrigger() {
setConfigMode();
// send trigger
streamPtr->write((uint8_t)0x42);
streamPtr->write((uint8_t)0x57);
streamPtr->write((uint8_t)0x02);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x00);
streamPtr->write((uint8_t)0x41);
}
// Private: Handles the low-level bits of communicating with the TFMini, and detecting some communication errors.
int TFMini::takeMeasurement() {
int numCharsRead = 0;
uint8_t lastChar = 0x00;
// Step 1: Read the serial stream until we see the beginning of the TF Mini header, or we timeout reading too many characters.
while (1) {
if (streamPtr->available()) {
uint8_t curChar = streamPtr->read();
if ((lastChar == 0x59) && (curChar == 0x59)) {
// Break to begin frame
break;
} else {
// We have not seen two 0x59's in a row -- store the current character and continue reading.
lastChar = curChar;
numCharsRead += 1;
}
}
// Error detection: If we read more than X characters without finding a frame header, then it's likely there is an issue with
// the Serial connection, and we should timeout and throw an error.
if (numCharsRead > TFMINI_MAXBYTESBEFOREHEADER) {
state = ERROR_SERIAL_NOHEADER;
distance = -1;
strength = -1;
if (TFMINI_DEBUGMODE == 1) Serial.println("ERROR: no header");
return -1;
}
}
// Step 2: Read one frame from the TFMini
uint8_t frame[TFMINI_FRAME_SIZE];
uint8_t checksum = 0x59 + 0x59;
for (int i = 0; i < TFMINI_FRAME_SIZE; i++) {
// Read one character
while (!streamPtr->available()) {
// wait for a character to become available
}
frame[i] = streamPtr->read();
// Store running checksum
if (i < TFMINI_FRAME_SIZE - 2) {
checksum += frame[i];
}
}
// Step 2A: Compare checksum
// Last byte in the frame is an 8-bit checksum
uint8_t checksumByte = frame[TFMINI_FRAME_SIZE - 1];
if (checksum != checksumByte) {
state = ERROR_SERIAL_BADCHECKSUM;
distance = -1;
strength = -1;
if (TFMINI_DEBUGMODE == 1) Serial.println("ERROR: bad checksum");
return -1;
}
// Step 3: Interpret frame
uint16_t dist = (frame[1] << 8) + frame[0];
uint16_t st = (frame[3] << 8) + frame[2];
uint8_t reserved = frame[4];
uint8_t originalSignalQuality = frame[5];
// Step 4: Store values
distance = dist;
strength = st;
state = MEASUREMENT_OK;
// Return success
return 0;
}
I use hardware serial for the TFMini.
I have ran this library on the Uno, MiniPro, Mega, STM32 Bluepill, Due, and ESP32. Works great.
Hi. I'm very new to this, and I'm trying to use a TFmini for a class assignment. How do I make use of the CPP, and .h file? It doesn't appear as though I can download them as a zip, then run them.
Also, do I need to download and install libraries to use these files? Or will my IDE for my Arduino Due already have the required libraries? I hope to get this working very soon. It looks like a fun device.
Add a file to you project, copy the h from the window on this page to the new file you added and named. Do the same with the cpp. The ccp and h file will be your library.