Part Number:EK-TM4C123GXL
Hi all,
I have connected the ultrasonic sensor to my MCU and flashed MCU with this simple code for obtaining the ultrasonic distance measurement and send it via UART:
#include "Wire.h"
//Processing incoming serial data
#include "Messenger.h"
//Contain definition of maximum limits of various data type
#include <limits.h>
Messenger Messenger_Handler = Messenger();
///////////////////////////////////////////////////////////////////////////////////////
//DMP options
//Set true if DMP init was successful
bool dmpReady = false;
//Holds actual interrupt status byte from MPU
uint8_t mpuIntStatus;
//return status after each device operation
uint8_t devStatus;
//Expected DMP paclet size
uint16_t packetSize;
//count of all bytes currently in FIFO
uint16_t fifoCount;
//FIFO storate buffer
uint8_t fifoBuffer[64];
float ypr[3];
// ================================================================
// === INTERRUPT DETECTION ROUTINE ===
// ================================================================
volatile bool mpuInterrupt = false; // indicates whether MPU interrupt pin has gone high
void dmpDataReady() {
mpuInterrupt = true;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Ultrasonic pins definition
const int echo = 9, Trig = 10;
long duration, cm;
/////////////////////////////////////////////////////////////////////////////////////////
//Time update variables
unsigned long LastUpdateMicrosecs = 0;
unsigned long LastUpdateMillisecs = 0;
unsigned long CurrentMicrosecs = 0;
unsigned long MicrosecsSinceLastUpdate = 0;
float SecondsSinceLastUpdate = 0;
//Setup serial, encoders, ultrasonic, MPU6050 and Reset functions
void setup()
{
//Init Serial port with 115200 baud rate
Serial.begin(115200);
SetupUltrasonic();
//Setup Reset pins
SetupReset();
//Set up Messenger
Messenger_Handler.attach(OnMssageCompleted);
}
//SetupEncoders() Definition
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Setup UltrasonicsSensor() function
void SetupUltrasonic()
{
pinMode(Trig, OUTPUT);
pinMode(echo, INPUT);
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Setup Reset() function
void SetupReset()
{
pinMode(GREEN_LED,OUTPUT);
pinMode(RESET_PIN,OUTPUT);
///Conenect RESET Pins to the RESET pin of launchpad,its the 16th PIN
digitalWrite(RESET_PIN,HIGH);
}
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//MAIN LOOP
void loop()
{
//Read from Serial port
Read_From_Serial();
//Send time information through serial port
Update_Time();
//Send ultrasonic values through serial port
Update_Ultra_Sonic();
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Read from Serial Function
void Read_From_Serial()
{
while(Serial.available() > 0)
{
int data = Serial.read();
Messenger_Handler.process(data);
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//OnMssg Complete function definition
void OnMssageCompleted()
{
char reset[] = "r";
char set_speed[] = "s";
if(Messenger_Handler.checkString(reset))
{
Serial.println("Reset Done");
Reset();
}
if(Messenger_Handler.checkString(set_speed))
{
//This will set the speed
Set_Speed();
return;
}
}
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Reset function
void Reset()
{
digitalWrite(GREEN_LED,HIGH);
delay(1000);
digitalWrite(RESET_PIN,LOW);
digitalWrite(GREEN_LED,LOW);
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Will update ultrasonic sensors through serial port
void Update_Ultra_Sonic()
{
digitalWrite(Trig, LOW);
delayMicroseconds(2);
digitalWrite(Trig, HIGH);
delayMicroseconds(10);
digitalWrite(Trig, LOW);
// The echo pin is used to read the signal from the PING))): a HIGH
// pulse whose duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
duration = pulseIn(echo, HIGH);
// convert the time into a distance
cm = microsecondsToCentimeters(duration);
//Sending through serial port
Serial.print("u");
Serial.print("\t");
Serial.print(cm);
Serial.print("\n");
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Update time function
void Update_Time()
{
CurrentMicrosecs = micros();
LastUpdateMillisecs = millis();
MicrosecsSinceLastUpdate = CurrentMicrosecs - LastUpdateMicrosecs;
if (MicrosecsSinceLastUpdate < 0)
{
MicrosecsSinceLastUpdate = INT_MIN - LastUpdateMicrosecs + CurrentMicrosecs;
}
LastUpdateMicrosecs = CurrentMicrosecs;
SecondsSinceLastUpdate = MicrosecsSinceLastUpdate / 1000000.0;
Serial.print("t");
Serial.print("\t");
Serial.print(LastUpdateMicrosecs);
Serial.print("\t");
Serial.print(SecondsSinceLastUpdate);
Serial.print("\n");
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Conversion of microsecond to centimeter
long microsecondsToCentimeters(long microseconds)
{
// The speed of sound is 340 m/s or 29 microseconds per centimeter.
// The ping travels out and back, so to find the distance of the
// object we take half of the distance travelled.
return microseconds / 29 / 2;
}
So I have connected my ultrasonic sensor to 5V, GND and PA7 pin and then after flashing the software I changed the mode to DEVICE and used pin PB1 to send the serial messages. Then, this PB1 pin is connected to my Odroid (like rasbperry) to UART Rx pin and all I get there are some garbage values. I have used the baud rate of 115200 on both devices.