Week 10. Output Devices¶
Hero Shot
After completing Input devices week, since this week being output devices we were involved in exploring different output devices in group and for Individual Assignment I explored on servo motor and speaker. As both of them are required during my final project so for that reason, I thought why not I just give a try on exploring and familiarising them before I actually starts working with my final project.
Assignments for the Week¶
Group Assignment:
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Measure the power consumption of an output device
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Document your work on the group work page and reflect on your individual page what you learned.
Link to the group Assignment is here
key takeaways from this week
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While giving the external power from DC power supply for the devices that we are working with, we should adjust and set the value of voltage and current equall to or little bit more than the nominal values of devices.
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Ensure to provide proper connections and ground connections while using the DC power supply.
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Never connect any devices with your microcontroller and laptop without referring to its datasheet because it is very important that we know how much current is being drawn by each components. This is mainly to avoid short circuiting of microcontroller board and to prevent laptop from going dead due to instant power drain by the devices.
-
I also had similar experience of directly connecting servo motor through laptop and while giving supply, my laptop died and I had to open it and remove the battery jack and reconnect it, then only it started working.
Individual Assignment:
- Add an output device to a microcontroller board you’ve designed and program it to do something.
This week being the output devices, I tried to explore on servo motor and the speaker (DF player) because I will be using both of them for my final project.
MG996R¶
I started setting up the servo motor MG996R by making necessary connections. Since this set up was conducted in group I included this in my invidual assignment as well and apart from that I also explored on Micro Servo 9g SG90 servo motor.
I had attached code below to do programing for the servo motor
#include <Servo.h>
Servo servo; // create servo object to control a servo
void setup() {
servo.attach(9); // attaches the servo on pin 9 to the servo objectư
servo.write(0); // rotate slowly servo to 0 degrees immediately
}
void loop() {
for (int angle = 0; angle <= 180; angle += 1) { // rotate slowly from 0 degrees to 180 degrees, one by one degree
// in steps of 1 degree
servo.write(angle); // control servo to go to position in variable 'angle'
delay(10); // waits 10ms for the servo to reach the position
}
for (int angle = 180; angle >= 0; angle -= 1) { // rotate from 180 degrees to 0 degrees, one by one degree
servo.write(angle); // control servo to go to position in variable 'angle'
delay(10); // waits 10ms for the servo to reach the position
}
}
The voltage and current drawn by MG996R during operation was recorded as;
-
Voltage: 6:00V
-
Ampere: 0.08A
Micro Servo 9g SG90¶
Next I went for Micro servo 9g SG90 in which I had made connection by giving the external power supply from DC power supply and signal pin connecting to microcontroller board.
The attached code below is used for programing the servo motor at certain angles
#include <Servo.h>
Servo myservo; // creating Servo motor to sweep in segmented angles
int sweepAngles[] = {0, 55, 110, 165, 180}; // Key angles are maintained so that I can rotate the servo motor as per my convenient
int currentIndex = 0;
bool forwardSweep = true; // Direction flag
void setup() {
myservo.attach(9); // Servo on pin 9
}
void loop() {
// Move to the next target angle
int targetAngle = sweepAngles[currentIndex];
smoothSweep(myservo.read(), targetAngle);
delay(2000); // Pause for 2 sec
// Update direction (forward or reverse)
if (forwardSweep) {
if (currentIndex < 4) currentIndex++; // Move to next angle
else {
forwardSweep = false; // Reverse direction after 180°
}
} else {
if (currentIndex > 0) currentIndex--; // Move to previous angle
else {
forwardSweep = true; // Forward direction after 0°
}
}
}
// Smooth sweep between two angles
void smoothSweep(int startAngle, int endAngle) {
int step = (startAngle < endAngle) ? 1 : -1; // Direction
for (int pos = startAngle; pos != endAngle; pos += step) {
myservo.write(pos);
delay(10); // Adjust speed (smaller = faster)
}
myservo.write(endAngle); // Ensure final angle is precise
}
The voltage and current drawn by Micro servo 9g SG90 during operation was recorded as;
-
Voltage: 6:00V
-
Ampere: 0.07A
Speaker (DF mini player)¶
After exploring the servo motor next I went for exploring the speaker as well as for my final project as it plays a key role. So for that purpose in order to make sure that I give proper connection for my device, I had referred to its datasheet and pinout diagram.
I connected the RX pin of DF player through 1K resistor to pin 11 0n arduino board and the TX pin of DF player to pin 10 of Arduino board with speaker. After that I uploaded the Mp3 file into the SD card and then inserted inside the DF player. Followed by that I compiled and uploaded the code.
Next I opened the Arduino IDE and ran the example code from there by following the steps mentioned below;
The attached code below is used for programing the DF player for playing MP3 file
#include "Arduino.h"
#include "DFRobotDFPlayerMini.h"
#if (defined(ARDUINO_AVR_UNO) || defined(ESP8266)) // Using a soft serial port
#include <SoftwareSerial.h>
SoftwareSerial softSerial(/*rx =*/10, /*tx =*/11);
#define FPSerial softSerial
#else
#define FPSerial Serial1
#endif
DFRobotDFPlayerMini myDFPlayer;
void printDetail(uint8_t type, int value);
void setup()
{
#if (defined ESP32)
FPSerial.begin(9600, SERIAL_8N1, /*rx =*/D3, /*tx =*/D2);
#else
FPSerial.begin(9600);
#endif
Serial.begin(115200);
Serial.println();
Serial.println(F("DFRobot DFPlayer Mini Demo"));
Serial.println(F("Initializing DFPlayer ... (May take 3~5 seconds)"));
if (!myDFPlayer.begin(FPSerial, /*isACK = */true, /*doReset = */true)) { //Use serial to communicate with mp3.
Serial.println(F("Unable to begin:"));
Serial.println(F("1.Please recheck the connection!"));
Serial.println(F("2.Please insert the SD card!"));
while(true){
delay(0); // Code to compatible with ESP8266 watch dog.
}
}
Serial.println(F("DFPlayer Mini online."));
myDFPlayer.volume(30); //Set volume value. From 0 to 30
myDFPlayer.play(1); //Play the second mp3
}
void loop()
{
static unsigned long timer = millis();
if (millis() - timer > 60000) {
timer = millis();
myDFPlayer.next(); //Play next mp3 every 1 second.
}
if (myDFPlayer.available()) {
printDetail(myDFPlayer.readType(), myDFPlayer.read()); //Print the detail message from DFPlayer to handle different errors and states.
}
}
void printDetail(uint8_t type, int value){
switch (type) {
case TimeOut:
Serial.println(F("Time Out!"));
break;
case WrongStack:
Serial.println(F("Stack Wrong!"));
break;
case DFPlayerCardInserted:
Serial.println(F("Card Inserted!"));
break;
case DFPlayerCardRemoved:
Serial.println(F("Card Removed!"));
break;
case DFPlayerCardOnline:
Serial.println(F("Card Online!"));
break;
case DFPlayerUSBInserted:
Serial.println("USB Inserted!");
break;
case DFPlayerUSBRemoved:
Serial.println("USB Removed!");
break;
case DFPlayerPlayFinished:
Serial.print(F("Number:"));
Serial.print(value);
Serial.println(F(" Play Finished!"));
break;
case DFPlayerError:
Serial.print(F("DFPlayerError:"));
switch (value) {
case Busy:
Serial.println(F("Card not found"));
break;
case Sleeping:
Serial.println(F("Sleeping"));
break;
case SerialWrongStack:
Serial.println(F("Get Wrong Stack"));
break;
case CheckSumNotMatch:
Serial.println(F("Check Sum Not Match"));
break;
case FileIndexOut:
Serial.println(F("File Index Out of Bound"));
break;
case FileMismatch:
Serial.println(F("Cannot Find File"));
break;
case Advertise:
Serial.println(F("In Advertise"));
break;
default:
break;
}
break;
default:
break;
}
}