Multiple tf mini LIDAR sensors on arduino problem

Help & Support Robot Parts
1

HI, I am a beginner with the whole LIDAR sensing technology and software serial on Arduino. Essentially I hooked up one tf mini to my Arduino using a logic level converter, and it worked splendidly. I then attempted to add a second sensor. But when I tried to get a reading from either of the sensors only one showed up in the serial monitor. Through testing I relized whatever LIDAR sensor serial begin went last gave readings. I am using an Arduino Uno, 5v 3.3v bidirectional logic level converter. This is the original code with one LIDAR:

#include <SoftwareSerial.h>
#include "TFMini.h"

// Setup software serial port 
SoftwareSerial mySerial(10, 11);      // Uno RX (TFMINI TX), Uno TX (TFMINI RX)
TFMini tfmini;

void setup() {
  // Step 1: Initialize hardware serial port (serial debug port)
  Serial.begin(115200);
  // wait for serial port to connect. Needed for native USB port only
  while (!Serial);
     
  Serial.println ("Initializing...");

  // Step 2: Initialize the data rate for the SoftwareSerial port
  mySerial.begin(TFMINI_BAUDRATE);

  // Step 3: Initialize the TF Mini sensor
  tfmini.begin(&mySerial);    
}


void loop() {
  // Take one TF Mini distance measurement
  uint16_t dist = tfmini.getDistance();
  uint16_t strength = tfmini.getRecentSignalStrength();

  // Display the measurement
  Serial.print(dist);
  Serial.print(" cm      sigstr: ");
  Serial.println(strength);

  // Wait some short time before taking the next measurement
  delay(25);  
}

I then tried to modify for 2 LIDAR. This is my Code:

#include <SoftwareSerial.h>
#include "TFMini.h"

// Setup software serial port 
SoftwareSerial mySerial(10, 11);      // Uno RX (TFMINI TX), Uno TX (TFMINI RX)
SoftwareSerial mySerial2(12, 13);
TFMini tfmini;
TFMini tfmini2;
void setup() {
  // Step 1: Initialize hardware serial port (serial debug port)
  Serial.begin(115200);
  // wait for serial port to connect. Needed for native USB port only
  while (!Serial);
     
  Serial.println ("Initializing...");

  // Step 2: Initialize the data rate for the SoftwareSerial port
  mySerial2.begin(TFMINI_BAUDRATE);
  mySerial.begin(TFMINI_BAUDRATE);
  // Step 3: Initialize the TF Mini sensor
  tfmini2.begin(&mySerial);
  tfmini.begin(&mySerial); 
     
}


void loop() {
  // Take one TF Mini distance measurement
  uint16_t dist = tfmini.getDistance();
  uint16_t strength = tfmini.getRecentSignalStrength();

  // Display the measurement
  Serial.print(dist);
  Serial.print(" cm      sigstr: ");
  Serial.println(strength);

  // Wait some short time before taking the next measurement
  delay(5000);  

  uint16_t dist2 = tfmini2.getDistance();
  uint16_t strength2 = tfmini2.getRecentSignalStrength();

  // Display the measurement
  Serial.print(dist2);
  Serial.print(" cm      sigstr: ");
  Serial.println(strength2);
  delay(5000);
}

Can anyone help with this problem.
Thanks!

3

Hey,

After a quick first glance I noticed you may want to verify your initialization line:

// Step 3: Initialize the TF Mini sensor
tfmini2.begin(&amp;mySerial);
tfmini.begin(&amp;mySerial);

It seems like you are not using the mySerial2 that you created above.
Try changing that and see if it helps out.

Sincerely,

P.-S.: Would you mind also linking to the library you are using? Does it happen to be this one? If so, which version are you using?
P.-S.#2: I added code tags to your post for clarity. I hope you don’t mind! :wink:

4

Thanks very much. I managed to fix the issue by calling the listen() function before retrieving data. I also made the corrections that you listed. Thanks for the help. The library am using is the TFmini .h library.

5

Hey,

That was going to be my next request of stuff to try out :slight_smile:

Good to know it works now. Enjoy the sensor!

Sincerely,

6

Can you share me the code of two lidar with single arduino?

7

Hey @spiderpro it’be great if you could post your updated program :slight_smile:
Thanks!