void setup(){
Serial.begin(9600);
pinMode(13, OUTPUT);
}
void loop() {
if (Serial.available() > 0){
int inChar = Serial.read();
if (inChar == 'H'){
digitalWrite(13, HIGH);
}
if (inChar == 'L'){
digitalWrite(13, LOW);
}
}
}
I have seen very similar programs. I don't get any compile errors, but the led light won't turn on. Is there an error in my code? Thanks
Sounds like a hardware issue. Double check that first.
Use a digital multimeter (DMM) to read the voltage between pin 13 and Arduino ground. It should output 5V when you send the 'H'. If it does, then your problem is the LED. If it does not output 5V when you send the 'H' then you have a software or serial communication issue.
Double check that you have the correct BAUD rate and COM port settings in whatever program is talking to the Arduino.
Related
Trying to run arduino code through pyserial,
Trying to run a code which communicates to the arduino to turn an LED on/off and stays in that HIGH/LOW state until otherwise communicated via the serial port again
the problem I am having is as soon as the python code has run the LED turns off and I can't figure out why its doing this.. any help would be much appreciated.
Arduino CODE
int data;
int EM=13;
#define ever
void setup() {
Serial.begin(9600); //initialize serial COM at 9600 baudrate
pinMode(EM, OUTPUT); //declare the LED pin (13) as output
digitalWrite (EM, LOW); //Turn OFF the Led in the beginning
Serial.println("Actuating Electromagnet");
}
void loop() {
if (Serial.available()>0) //whatever the data that is coming in serially and assigning the value to the variable “data”
{
data = Serial.read();
Serial.println(data);
}
if (data == '1')
digitalWrite (EM, HIGH); //Turn On the Led
else if (data == '0')
digitalWrite (EM, LOW); //Turn OFF the Led
PYTHON SCRIPT
import serial
import time
ArduinoUnoSerial = serial.Serial('/dev/cu.usbmodem1411',9600)
time.sleep(2)
print ArduinoUnoSerial.readline()
ArduinoUnoSerial.write('1')
I've got an Arduino which works with the following basic example for blinking:
void setup() {
pinMode(13, OUTPUT);
}
void loop() {
digitalWrite(13, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(13, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second
}
But if I add Serial.println it doesn't blink and doesn't output anything to the Serial moniter:
void setup() {
pinMode(13, OUTPUT);
Serial.begin(115200);
}
void loop() {
Serial.println("Loop");
digitalWrite(13, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(13, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second
}
What am I doing wrong?
You're not doing anything wrong you may have a bad chip, or your baud rate too high, try 9600
Also can you give me details on your chip, some chips don't have serial.
If you're using the same chip as the leonardo you may need this:
Serial.begin(9600);
while (!Serial) {} //Wait for serial port to connect
When you change the baud rate in Serial.begin(115200) the receiving terminal should have the same baud rate or you will see nothing there.
I have an Arduino UNO R3 that reads a specific value from my Web Page.
I have an LED attached to the PIN 13 & GND of my Arduino.
When the Arduino reads 1 from my Web Page, it should turn the LED ON. When it reads 0, it should turn it off.
Following is the code for that:
#include "SIM900.h"
#include <SoftwareSerial.h>
#include "inetGSM.h"
InetGSM inet;
#define ledPin 13
char msg[165];
char store[2];
char a;
char b;
char* disp;
boolean started=false;
void setup()
{
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, LOW);
//Serial connection.
Serial.begin(9600);
Serial.println("GSM Shield testing.");
//Start configuration of shield with baudrate.
//For http uses is raccomanded to use 4800 or slower.
if (gsm.begin(2400)) {
Serial.println("\nstatus=READY");
started=true;
} else Serial.println("\nstatus=IDLE");
if(started)
{
//GPRS attach, put in order APN, username and password.
//If no needed auth let them blank.
if (inet.attachGPRS("TATA.DOCOMO.INTERNET", "", ""))
Serial.println("status=ATTACHED");
else Serial.println("status=ERROR");
delay(1000);
//TCP Client GET, send a GET request to the server and
//save the reply.
//Print the results.
}
}
void loop()
{
inet.httpGET("www.boat.esy.es", 80, "/retrieve.php", msg, 165);
disp = strstr(msg,"\r\n\r\n");
disp = disp+4;
a = disp[0];
b = disp[1];
Serial.println(b);
if(b=='1')
{
digitalWrite(ledPin, HIGH);
}
if(b=='0');
{
digitalWrite(ledPin, LOW);
}
}
Problem here is, when I disable the digitalWrite(ledPin,LOW), that is when I comment it out, the LED turns on & stays that way.
But the moment I enable it & load the code on my Arduino, it won't even turn on.
I'm wondering if it's a logical error or something else. Because the turning on & off of the LED depends completely on the conditions being satisfied. And for now, my Web Page returns only 1, hence the LED should stay on. But when I include both digitalWrite(ledPin, HIGH) and digitalWrite(ledPin, LOW) in the same code and run it, it doesn't work. I can see the Serial printing out the messages associated with the LED ON, but I don't see the LED turning ON.
Thank You for your time!!
First of all you have a semicolon that I think should not be in your second if-statement?
if(b=='0'); <--
{
digitalWrite(ledPin, LOW);
}
Start by trying to remove that and see if there is a difference.
Hi I am trying to learn coding microcontrollers on my own. I am trying to code my arduino board (ATMEGA8A-PU) in embedded C using the arduino ide itself. I have blinked my LED so far. Now I am trying to control its state using the serial monitor(sending "on" lights it up and "off" switches it off). But I don't know the C commands to do it.I successfully did it using the arduino Serial commands.
int led = 13; // Pin 13
void setup()
{
pinMode(led, OUTPUT); // Set pin 13 as digital out
// Start up serial connection
Serial.begin(9600); // baud rate
Serial.flush();
}
void loop()
{
String input = "";
// Read any serial input
while (Serial.available() > 0)
{
input += (char) Serial.read(); // Read in one char at a time
delay(5); // Delay for 5 ms so the next char has time to be received
}
if (input == "on")
{
digitalWrite(led, HIGH); // on
}
else if (input == "off")
{
digitalWrite(led, LOW); // off
}
}
So please help.
You are using Serial class and functions like begin(), print() etc from the Serial class which is C++ language. These are the C++ commands native to the Arduino development environment. So anyway you ar using C/C++ commands here.
I'm trying to do a project where BLUNO (Arduino UNO + BLE) will connect to an iBeacon and make use of the RSSI detected.
I've already made contact between the BLUNO and the iBeacon through the AT commands. I can get RSSI result in the Arduino IDE serial monitor when I ping it with AT commands.
My problem now is in sending those AT commands through an Arduino sketch. I know I've to use Serial Communication, but my Serial.Available function never returns more than 0.
void setup() {
pinMode(13, OUTPUT);
Serial.begin(115200);
Serial.print("+++\r\n");
Serial.print("AT+RSSI=?\r\n");
}
void loop(){
if(Serial.available()){
digitalWrite(13, HIGH);
delay(5000);
}
}
What is irritating me is that I can connect BLUNO to my iPhone and get the RSSI on the serial monitor through AT commands. But that above code doesn't work!
Any help?
I'm almost done with the whole project for now.
my mistake in the last code was the initiation part that has to be done before the AT commands. The right way is
Serial.begin(115200); //Initiate the Serial comm
Serial.print("+");
Serial.print("+");
Serial.print("+"); // Enter the AT mode
delay(500); // Slow down and wait for connection establishment
instead of
Serial.print("+++\r\n");
so yeah the rest is kind of alright. Keep in mind that this BLE thing REALLY sucks in terms of accuracy in locating a beacon. The RSSI reading keep fluctuating and the calculated distance using the simplified equation here somewhere on Stack overflow is REALLY unreliable.
So yeah keep that in mind yo!
Here's my full code just for reference.
// while the AT connection is active, the serial port between the pc and the arduino is occuipied.
// You can manipluate the data on arduino, but to display on the serial monitor you need to exit the AT mode
char Data[100];
char RAW[3];
int INDEX;
char Value = '-';
void setup() {
pinMode(13, OUTPUT); // This the onboard LED
pinMode(8, OUTPUT); // This is connected to the buzzer
Serial.begin(115200); //Initiate the Serial comm
Serial.print("+");
Serial.print("+");
Serial.print("+"); // Enter the AT mode
delay(500); // Slow down and wait for connectin establishment
}
void loop(){
Serial.println("AT+RSSI=?"); // Ask about the RSSI
for(int x=0 ; Serial.available() > 0 ; x++ ){ // get the Enter AT mode words
//delay(20); // Slow down for accuracy
Data[x] = Serial.read(); // Read and store Data Byte by Byte
if (Data[x] == Value ) // Look for the elemnt of the array that have "-" that's the start of the RSSI value
{
INDEX=x;
}
}
//Serial.println("AT+EXIT");
RAW[0] = Data[INDEX]; // Copy the RSSI value to RAW Char array
RAW[1] = Data[INDEX+1];
RAW[2] = Data[INDEX+2];
RAW[3] = Data[INDEX+3];
int RSSI = atoi(RAW); //Convert the Array to an integer
//Serial.println(RSSI);
//delay(200); // Give the program time to process. Serial Comm sucks
double D = exp(((RSSI+60)/-10)); //Calculate the distance but this is VERY inaccurate
//Serial.println(D);
if (D>1.00) // If the device gets far, excute the following>>
{
digitalWrite(13, HIGH);
digitalWrite(8, HIGH);
delay(500);
digitalWrite(13, LOW);
digitalWrite(8, LOW);
delay(500);
}
}