Tutorial – How to control motor with The Tactigon – Part II

In this article we’re going to learn how to connect The Tactigon to a motor control board and communicate with it. Part II - Sketch

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Tutorial – How to control motor with The Tactigon – Part II

Things used in this project

Hardware components

The Tactigon One

Software apps and online services

Arduino IDE

Story

Overview

As we saw in the previous project, The Tactigon can be connected to a serial motor control board. In this article we’ll look at how to handle it via software. The Tactigon will receive commands sent by the controller connected in BLE, and will communicate to the motor control board motor speeds.

Sketch

The sketch running on The Tactigon exposes a BLE Characteristic in which the Controller can write in. You can use every BLE Central unit as controller as long as it sends customizable data. The motor board read a single Byte where:

Serial Transmission

The Tactigon UART library exposes a function to send chars. We use this library to communicate with the motor control board.

We prepare a callback to be triggered when the BLE Characteristic receives something:

In the setup() we initialize LEDs and turn them off, initialize the BLE Peripheral Mode, create the BLE Characteristic and its UUID, and assign the callbacks created.

Since callbacks handle serial communication, loop() will only cycle LEDs.

Conclusion

The Tactigon UART library gave us the ability to control a tracked rover, but everything with an UART interface can be connected to The Tactigon. Remember to download the source code below!

CINGO.ino

#include <tactigon_led.h>
#include <tactigon_BLE.h>
#include <tactigon_UserSerial.h>


//RGB LEDs
T_Led rLed, bLed, gLed;

//BLE Manager, BLE Characteristic and its UUID
T_BLE bleManager;
T_BLE_Characteristic cmdChar;
UUID uuid;

//UART 
T_UserSerial tSerial;

//Used for LEDs cycle
int  ticksLed, stp;

/*----------------------------------------------------------------------*/
void cbBLEcharWritten(uint8_t *pData, uint8_t dataLen)
{
  //Sends received data to uart
  tSerial.write((char*)pData, dataLen);
  //Blinks LEDs, turned off by next state in loop()
  rLed.on();
  gLed.on();
  bLed.on();
}

/*----------------------------------------------------------------------*/
void cbUartRxByte(uint8_t bb){
  
}

/*----------------------------------------------------------------------*/
void cbUartRxLine(uint8_t *pLine, uint8_t len){

}

/*----------------------------------------------------------------------*/
void setup() {

  char charProg;

  ticksLed = 0;
  stp = 0;

  rLed.init(T_Led::RED);
  gLed.init(T_Led::GREEN);
  bLed.init(T_Led::BLUE);

  rLed.off();
  gLed.off();
  bLed.off();

  //init role
  bleManager.InitRole(TACTIGON_BLE_PERIPHERAL);

  uuid.set("c1c0760d-503d-4920-b000-101e7306b001");   //command char
  cmdChar = bleManager.addNewChar(uuid, 18, 1);
  charProg = cmdChar.setWcb(cbBLEcharWritten);

  //init user serial
  tSerial.init(T_UserSerial::B_9600);
  tSerial.setRxByteCB(cbUartRxByte);
  tSerial.setRxLineCB(cbUartRxLine);

}

/*----------------------------------------------------------------------*/
void loop() {
  
  //Cycle rgb leds
  if (GetCurrentMilli() >= (ticksLed + (1000 / 1)))
  {
    char buff[4];
    int i;

    ticksLed = GetCurrentMilli();

    if (stp == 0)
    {
      rLed.on();
      gLed.off();
      bLed.off();
    }
    else if (stp == 1)
    {
      rLed.off();
      gLed.on();
      bLed.off();
    }
    else if (stp == 2)
    {
      rLed.off();
      gLed.off();
      bLed.on();
    }

    stp = (stp + 1) % 3;
  }

}

Credits

Massimiliano

29 projects • 112 followers

I'm an engineer and I like robotics, embedded systems and linux. I spent a lot of time in automation and firmware development.

Michele Valentini

20 projects • 67 followers

From Pepper growing to CNC milling, i don't like to waste time sleeping

Tutorial – How to control motor with The Tactigon – Part II