Category Archives: Tutorial

Arduino Tutorial 48: Connecting and Using an LCD Display

February 11, 2020 admin

LCD Arduino — LCD connected to an Arduino.

It is often times useful to “un-tether” your arduino from your desktop PC, in order to have a system you can walk around with, and interact with the real world. One of the first steps in making this happen is to have some sort of display on your arduino project. In this lesson, we show you how to connect and program your project to be able to display simple messages on the LCD. This is a schematic diagram of how to connect the arduino to an LCD display. Many LCD displays in fact share this same connection schematic.

Arduino LCD Schematic — This schematic will allow you to connect the LCD to the arduino.

The details are provided in the following video.

Below is the code we developed in the video.

#include <LiquidCrystal.h>
int rs=7;
int en=8;
int d4=9;
int d5=10;
int d6=11;
int d7=12;
LiquidCrystal lcd(rs,en,d4,d5,d6,d7);
void setup() {
  // put your setup code here, to run once:
lcd.begin(16,2);
}

void loop() {
lcd.setCursor(0,0);
lcd.print("Watch me Count");
for (int j=1;j<=10;j=j+1){
  lcd.setCursor(0,1);
  lcd.print(j);
  delay(500);
 
}
 lcd.clear();
}

#include <LiquidCrystal.h>

int rs=7;

int en=8;

int d4=9;

int d5=10;

int d6=11;

int d7=12;

LiquidCrystal lcd(rs,en,d4,d5,d6,d7);

void setup() {

// put your setup code here, to run once:

lcd.begin(16,2);

}

void loop() {

lcd.setCursor(0,0);

lcd.print("Watch me Count");

for (int j=1;j<=10;j=j+1){

lcd.setCursor(0,1);

lcd.print(j);

delay(500);

}

lcd.clear();

}

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Arduino, Tutorial

Arduino Tutorial 47: Binary and Hexadecimal Bit Flipper

February 4, 2020 admin

In this lesson we explore how to create a Binary or Hexadecimal Bit Flipper. From our earlier lessons you see we can visually represent Hexadecimal or Binary numbers with a series of LED, with an on LED representing a “1” and an off LED representing a “0”. In programming and circuit applications, it is sometimes useful to “flip” or invert the bits. For an 8 bit number, one could do this in a program with 255 IF statements, but there is a simpler way. If you think about it, you can get the flippedByte by simple subtracting the byte from 0xFF, or 0b11111111. If you try some test cases, you can see that this will always work.

Simply stated, flippedByte=0xFF-Byte,

or if you prefer thinking in binary,

flippedByte=0b11111111-Byte

This is the circuit we are using to drive the 8 LED with the 74HX595 chip, and all this was explained in Tutorial 42.

This is the schematic we use in this example to control 8 LEDs from the 74HC595 chip.

This is the code which we developed in the video above.

int latchPin=11;
int clockPin=9;
int dataPin=12;
int dt=1000;

byte myByte=0x18;
byte myByteFlipped;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(latchPin,OUTPUT);
pinMode(dataPin,OUTPUT);
pinMode(clockPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(latchPin,LOW);
shiftOut(dataPin,clockPin,LSBFIRST,myByte);
digitalWrite(latchPin,HIGH);
delay(dt);
myByteFlipped=255-myByte;
digitalWrite(latchPin,LOW);
shiftOut(dataPin,clockPin,LSBFIRST,myByteFlipped);
digitalWrite(latchPin,HIGH);
delay(dt);
}

int latchPin=11;

int clockPin=9;

int dataPin=12;

int dt=1000;

byte myByte=0x18;

byte myByteFlipped;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(latchPin,OUTPUT);

pinMode(dataPin,OUTPUT);

pinMode(clockPin,OUTPUT);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(latchPin,LOW);

shiftOut(dataPin,clockPin,LSBFIRST,myByte);

digitalWrite(latchPin,HIGH);

delay(dt);

myByteFlipped=255-myByte;

digitalWrite(latchPin,LOW);

shiftOut(dataPin,clockPin,LSBFIRST,myByteFlipped);

digitalWrite(latchPin,HIGH);

delay(dt);

}

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Arduino, Tutorial

Arduino Tutorial 46: HOMEWORK- Create a Binary Bit Flipper with the 74HC595

January 28, 2020 admin

The purpose of this lesson is to assign you homework. Your homework is to create a Bit Flipper. That is, for an 8 bit Binary or Hex number, invert the bits . . . “1” bits should become “0” and “0” bits should become “1”. For example,

if myByte=00001111

the flipped version of this would be

myByteFlipped=11110000

Similarly if myByte=00000001

myByteFlipped=11111110

You could do this with 255 if statements, but see if you can figure out a better way of doing it, and then demonstrate your results using the circuit we have been using in the last few lessons.

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Arduino, Arduino 9-Axis IMU Totorials, Tutorial

9-Axis IMU LESSON 24: How To Build a Self Leveling Platform with Arduino

January 23, 2020 admin

In this lesson we develop the initial simple code for leveling the platform. We implement the simplest control system, which is to just increment or decrement the servos based on whether the actual position is greater or less than the target position. We increment/decrement by one degree, since this is the smallest allowed change in servo position. Next week we will implement a more sophisticated control system. Below is the arduino code developed in this lesson.

// ====================================================================
// DISCLAIMER:
// This code is provided as-is for educational and experimental 
// purposes only. The author makes no representations or warranties of 
// any kind concerning the safety, suitability, or accuracy of this 
// code. Use at your own risk. The author assumes no liability for any 
// damages, system failures, security breaches, or network issues 
// resulting from the use or implementation of this script.
// ====================================================================

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BNO055.h>
#include <utility/imumaths.h>
#include <math.h>
#include <Servo.h>

Servo pitchServo;
Servo rollServo;

float q0;
float q1;
float q2;
float q3;

float rollTarget=0;
float rollActual;
float rollError;
float rollServoVal=90;

float pitchTarget=0;
float pitchActual;
float pitchError;
float pitchServoVal=90;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
myIMU.begin();
delay(1000);
int8_t temp=myIMU.getTemp();
myIMU.setExtCrystalUse(true);
rollServo.attach(2);
pitchServo.attach(3);

rollServo.write(rollServoVal);
delay(20);
pitchServo.write(pitchServoVal);
delay(20);
}

void loop() {
  // put your main code here, to run repeatedly:
uint8_t system, gyro, accel, mg = 0;
myIMU.getCalibration(&system, &gyro, &accel, &mg);

imu::Quaternion quat=myIMU.getQuat();

q0=quat.w();
q1=quat.x();
q2=quat.y();
q3=quat.z();

rollActual=atan2(2*(q0*q1+q2*q3),1-2*(q1*q1+q2*q2));
pitchActual=asin(2*(q0*q2-q3*q1));

rollActual=rollActual/(2*3.141592654)*360;
pitchActual=pitchActual/(2*3.141592654)*360;

rollError=rollTarget-rollActual;
pitchError=pitchTarget-pitchActual;

if (pitchError>1.5){
  pitchServoVal=pitchServoVal+1;
  pitchServo.write(pitchServoVal);
  delay(20);
}
if (pitchError<-1.5){
  pitchServoVal=pitchServoVal-1;
  pitchServo.write(pitchServoVal);
  delay(20);
}

if (rollError>1.5){
  rollServoVal=rollServoVal+1;
  rollServo.write(rollServoVal);
  delay(20);
}
if (rollError<-1.5){
  rollServoVal=rollServoVal-1;
  rollServo.write(rollServoVal);
  delay(20);
}

Serial.print(rollTarget);
Serial.print(",");
Serial.print(rollActual);
Serial.print(",");
Serial.print(pitchTarget);
Serial.print(",");
Serial.print(pitchActual);
Serial.print(",");
Serial.print(accel);
Serial.print(",");
Serial.print(gyro);
Serial.print(",");
Serial.print(mg);
Serial.print(",");
Serial.println(system);

delay(BNO055_SAMPLERATE_DELAY_MS);
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

// ====================================================================

// DISCLAIMER:

// This code is provided as-is for educational and experimental

// purposes only. The author makes no representations or warranties of

// any kind concerning the safety, suitability, or accuracy of this

// code. Use at your own risk. The author assumes no liability for any

// damages, system failures, security breaches, or network issues

// resulting from the use or implementation of this script.

// ====================================================================

#include <Wire.h>

#include <Adafruit_Sensor.h>

#include <Adafruit_BNO055.h>

#include <utility/imumaths.h>

#include <math.h>

#include <Servo.h>

Servo pitchServo;

Servo rollServo;

float q0;

float q1;

float q2;

float q3;

float rollTarget=0;

float rollActual;

float rollError;

float rollServoVal=90;

float pitchTarget=0;

float pitchActual;

float pitchError;

float pitchServoVal=90;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {

// put your setup code here, to run once:

Serial.begin(115200);

myIMU.begin();

delay(1000);

int8_t temp=myIMU.getTemp();

myIMU.setExtCrystalUse(true);

rollServo.attach(2);

pitchServo.attach(3);

rollServo.write(rollServoVal);

delay(20);

pitchServo.write(pitchServoVal);

delay(20);

}

void loop() {

// put your main code here, to run repeatedly:

uint8_t system, gyro, accel, mg = 0;

myIMU.getCalibration(&system, &gyro, &accel, &mg);

imu::Quaternion quat=myIMU.getQuat();

q0=quat.w();

q1=quat.x();

q2=quat.y();

q3=quat.z();

rollActual=atan2(2*(q0*q1+q2*q3),1-2*(q1*q1+q2*q2));

pitchActual=asin(2*(q0*q2-q3*q1));

rollActual=rollActual/(2*3.141592654)*360;

pitchActual=pitchActual/(2*3.141592654)*360;

rollError=rollTarget-rollActual;

pitchError=pitchTarget-pitchActual;

if (pitchError>1.5){

pitchServoVal=pitchServoVal+1;

pitchServo.write(pitchServoVal);

delay(20);

}

if (pitchError<-1.5){

pitchServoVal=pitchServoVal-1;

pitchServo.write(pitchServoVal);

delay(20);

}

if (rollError>1.5){

rollServoVal=rollServoVal+1;

rollServo.write(rollServoVal);

delay(20);

}

if (rollError<-1.5){

rollServoVal=rollServoVal-1;

rollServo.write(rollServoVal);

delay(20);

}

Serial.print(rollTarget);

Serial.print(",");

Serial.print(rollActual);

Serial.print(",");

Serial.print(pitchTarget);

Serial.print(",");

Serial.print(pitchActual);

Serial.print(",");

Serial.print(accel);

Serial.print(",");

Serial.print(gyro);

Serial.print(",");

Serial.print(mg);

Serial.print(",");

Serial.println(system);

delay(BNO055_SAMPLERATE_DELAY_MS);

}

Arduino, Tutorial

Arduino Tutorial 45: Understanding Circular Shift Left and Circular Shift Right with the 74HC595

January 21, 2020 admin

In this lesson we explore the Circular Shift Left (CSL) and Circular Shift Right (CSR) binary functions. These functions are similar to the Logical Shift Left and Logical Shift Right functions explained in the previous lesson.

As a reminder, we are doing this work on the circuit built in Tutorial 42. As a refresher, we are using the 74HC595 Serial to Parallel converter, connected to an Arduino according to the following schematic.

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

The Circular Shift Left function is illustrated below:

You can see that all bits shift to the left, with the Most Significant Bit, or MSB looping back to the Least Significant Bit, or LSB position.

Similarly, the Circular Shift Right Function is as follows:

There is actually a very easy way to implement this in a program. We illustrate it with an arduino program. Lets first consider the CSL function. We will first consider how to move the MSB to the LSB position. Remember from our earlier lessons, that dividing a binary number by 2 moves the bits to the right. We want to move the MSB 7 positions to the right, so we would divide by 2⁷, which is 128. So, if we have a binary number myByte, we could move the MSB to the LSB by the equation:

myByte=myByte/128

With this we do the hardest part, which is to get the MSB to the LSB. Now we need to get the rest of the bits back, and in the left shifted position, we do that by multiplying by two. By combining these two functions, we end up with the solution of CSL being:

myByte=myByte/128+myByte*2

This simple equation will perform the CSL operation, when myByte is a Hexadecimal or Binary number (Byte type in Arduino).

We show the code below to implement the CSL an arduino with a 74HC595 chip:

int latchPin=11;
int clockPin=9;
int dataPin=12;
int dt=1000;

byte myByte=0b11111110;


void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(latchPin,OUTPUT);
pinMode(dataPin,OUTPUT);
pinMode(clockPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(latchPin,LOW);
shiftOut(dataPin,clockPin,LSBFIRST,myByte);
digitalWrite(latchPin,HIGH);
Serial.println(myByte,BIN);
delay(dt);
myByte=myByte/128+myByte*2;
}

int latchPin=11;

int clockPin=9;

int dataPin=12;

int dt=1000;

byte myByte=0b11111110;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(latchPin,OUTPUT);

pinMode(dataPin,OUTPUT);

pinMode(clockPin,OUTPUT);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(latchPin,LOW);

shiftOut(dataPin,clockPin,LSBFIRST,myByte);

digitalWrite(latchPin,HIGH);

Serial.println(myByte,BIN);

delay(dt);

myByte=myByte/128+myByte*2;

}

Similarly, the CSR binary function can be achieved with the equation:

myByte=myByte*128+myByte/2

This is the code we use for CSR on the Arduino.

int latchPin=11;
int clockPin=9;
int dataPin=12;
int dt=1000;

byte myByte=0b11111110;


void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(latchPin,OUTPUT);
pinMode(dataPin,OUTPUT);
pinMode(clockPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(latchPin,LOW);
shiftOut(dataPin,clockPin,LSBFIRST,myByte);
digitalWrite(latchPin,HIGH);
Serial.println(myByte,BIN);
delay(dt);
myByte=myByte*128+myByte/2;
}

int latchPin=11;

int clockPin=9;

int dataPin=12;

int dt=1000;

byte myByte=0b11111110;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(latchPin,OUTPUT);

pinMode(dataPin,OUTPUT);

pinMode(clockPin,OUTPUT);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(latchPin,LOW);

shiftOut(dataPin,clockPin,LSBFIRST,myByte);

digitalWrite(latchPin,HIGH);

Serial.println(myByte,BIN);

delay(dt);

myByte=myByte*128+myByte/2;

}

Technology Tutorials

Category Archives: Tutorial

Arduino Tutorial 48: Connecting and Using an LCD Display

Arduino Tutorial 47: Binary and Hexadecimal Bit Flipper

Arduino Tutorial 46: HOMEWORK- Create a Binary Bit Flipper with the 74HC595

9-Axis IMU LESSON 24: How To Build a Self Leveling Platform with Arduino

Arduino Tutorial 45: Understanding Circular Shift Left and Circular Shift Right with the 74HC595

Making The World a Better Place One High Tech Project at a Time. Enjoy!