i want to code a simple Hello World code in Arduino to show it on its system monitor, my code is:
void setup() // run once, when the sketch starts
{
Serial.begin(9600); // set up Serial library at 9600 bps
Serial.println("Hello world!"); // prints hello with ending line break
}
void loop() // run over and over again
{
// do nothing!
}
but when i run this code, i get This Image characters on the system monitor.Also, i change the Serial.begin() from 9600 to other things but it does not work!How can i fix the problem?
Check your BAUD Rate on the Serial Monitor. Make sure its 9600, as you told it should be in your code:
Serial.begin(9600);
In the bottom of the Serial Monitor, there is a drop down to select the baud rate:
Your linked < This Image > shows a lot of garbage.
Wrong baud rate would rarely produce that much (mow many resets are seen there?
What type of arduino do you use?
Can you assure SerialMonitor in the Arduino IDE is connected to Serial on your Arduino?
Related
Good morning everyone.
I am trying to establish serial communication between an arduino mega and an esp32, in both I am using hardware serials.
In the arduino the uart3 in the esp the uart2. I have checked the pin connections several times.
I also adapted the arduino's tx signal to the esp32 with a level shifter.
Essentially I need to send a string to the esp32.
The code of the arduino is as follows:
String InvioDatiESP() {
String da_passare = ("hello!!!");
return(da_passare);
}
void setup() {
Serial.begin(9600);
Serial3.begin(115200);
}
void loop() {
Serial3.println(InvioDatiESP());
Serial.println(InvioDatiESP());
delay(1000);
}
I create the string in a function since it is a reduced version of the actual code in which the string is to be composed.
The code of Esp32 is as follows:
#define RXp2 16
#define TXp2 17
void setup() {
Serial.begin(115200);
Serial2.begin(115200, SERIAL_8N1, RXp2, TXp2);
}
void loop() {
Serial.println(Serial2.readString());
}
I correctly set the boudrate in both serial ports on the IDE to verify communication.
The thing I notice that makes me doubt that the problem is related only to the ESP32 reading the string is that in the serial port of the ESP32 in the IDE while the program is running, blank lines are printed on the screen exactly every 1000ms, as if the data is received but not interpreted correctly.
How could I solve this in your opinion?
Thanks in advance for the answers!
SOLVED, the lever shifter was disturbing the signal too much, seen with the oscilloscope, I used a resistive divider and everything works perfectly, thank you all the same!
EDIT: Can you try to lower the boudrate? Check to see if with a lower one it will start decoding properly.
Your problem is not with the code, it's with the hardware. The arduino Mega2560 is using 5V logic level and ESP32 is using 3.3V.
You need to do some level shifting to be able to communicate.
You can take a look at this article to learn more about it.
Hope it helps.
i have a Genuino101 board and HM-11 module. Im trying to set the parameters of the module like name, etc. So i started with a simple code but it doesnt work. As we can see, my serial monitor is supposed to show "SETUP 1" and "SETUP 2". But this is what my serial monitor shows.
SETUP 1
It did not show or print "SETUP 2". So im guessing the problem is in between. I tried to comment out mySerial.begin(4800); and saw that this.
SETUP 1SETUP 2LOOP
LOOP
LOOP
LOOP
LOOP
LOOP
it works as it should except that i removed the mySerial.begin(4800).
Is this a softwareSerial problem? I also tried changing baud to 9600 but still problem arises. Looks like mySerial.begin(4800) pauses the arduino. Please help.
#include <SoftwareSerial.h>
SoftwareSerial mySerial(2,3);
void setup(){
Serial.begin(9600);
delay(2000);
Serial.print("SETUP 1");
mySerial.begin(4800);
delay(2000);
Serial.print("SETUP 2");
mySerial.print("AT+NAMEMASTER0000");
}
void loop(){
delay(1000);
Serial.println("LOOP");
}
EDIT:
The problem was the code paused halfway because of an error in initialization of software serial caused by RX/TX pins being interchanged. The problem was fixed automatically after swapping RX/TX pins.
I know this sounds really silly, but I really can't figure it out. I'm loading the following arduino code on an arduino uno:
void setup() {
Serial.begin(9600);
Serial.println("HELLO");
}
void loop() {
// put your main code here, to run repeatedly:
}
I'm uploading the code on the board and if I open a serial monitor repeatedly, I get different outputs. I'm expecting the output HELLO, and I get that sometimes. But I also get outputs like: HELLHELLO or HHELLO. I also loaded the same code on an arduino nano and it behaves similar.
Can someone please explain why this is happening? Is this an issue?
This could be due to the usb to serial buffer still containing data from the previous reset.
Try storing the string in PROGMEM to keep the string in flash memory rather than in RAM and see if that helps.
You need to set the baud rate to match to 9600 in the serial monitor, mismatched rates can cause unexpected output like you saw.
I am trying to read the data from a Ultra Sonic Fuel Sensor(the link).The Baud rate of this device is 9600.The device basically sends data at regular time intervals.I am able to read the output in the PC using Terminal software.Given below is a sample.
Eg:*XD,205B,00,0000,0031,0000,0000,null#
I am trying to connect this device to Arduino through serial port provided in the device and when I see the Serial Monitor,the output is not correct.Given below is the sample.
5320215115451166102572432302302432302302302302432303816623024323023023023024323023023023051822281141463
String incoming_char; // Will hold the incoming character from the Serial Port.
void setup()
{
//Initialize serial ports for communication.
Serial.begin(9600);
Serial1.begin(9600);
Serial.println("Starting Communication with Fuel Sensor");
}
void loop()
{
//If a character comes in from the cellular module...
if(Serial1.available() >0)
{
incoming_char=String(Serial1.read()); // Get the character from the cellular serial port.
Serial.print(incoming_char); // Print the incoming character to the terminal.
}
}
The Arduino is powered from USB and the Device from a 12V supply.
The voltage levels from the device Tx-GND=-5.44V,Rx-GND=-8.22V.
I initially thought the the issue might be because of the voltage range and made a voltage divider circuit and fed Arduino the proportionate voltage.Even that is not working.
So,what is the thing which is going wrong ?Please guide me.
Since you are using Serial1 I am assuming you are using an Arduino Mega?
From your question I would say the issue isn't voltage etc. but more likely to be how you are reading the data. You are assuming that the sensor will be returning char values. Are there any specifications on what is being returned?
I created a similar project using an Arduino. Except my Ultrasonic device was used as a range finder. There are details here. As you can see in the code the range is returned from the sensor as a two byte integer.
You will need to find out what the what the Ultra Sonic Fuel Sensor is returning and read in a similar fashion.
allright i would start by suggesting that you connect this to an analog pin to read. you will have to find the ratio between the fuel hight and voltage by measuring and dividing. then insert the multiplication in the code and you are set it will look like the hight instead of just a voltage
This is just a wild guess since I don't own an Arduino Mega (I have Duemilanove and Uno), but I've worked on projects wherein I've encountered issues similar to what you have. Sometimes adding a delay() on your void loop() block helps and gives it enough time for the arduino to read the bytes from the buffer. For 9600 baud rate, it usually takes about 1 ms to read 1 byte so adding a delay is necessary.
void loop()
{
//If a character comes in from the cellular module...
if(Serial1.available() >0)
{
incoming_char=String(Serial1.read()); // Get the character from the cellular serial port.
Serial.print(incoming_char); // Print the incoming character to the terminal.
}
delay(100);
}
Thank you all ! for your Value inputs.The problem was, I was trying to connect RS232 Serial(Works with Negative Voltages) to TTL serial interface(Works with 0 to some Positive Voltages) used in Arduino. Apparently,I was supplying negative voltages to Arduino whereas it was expected to give Positive voltages. So, got a RS232-to-TTL connector and it worked,finally.
i am having trouble getting data from two sensors using two software serial ports with an arduino board. I noticed a similar question might have been asked before but the answers suggest it can't be done and I know fully well it can based on the example here (http://arduino.cc/en/Tutorial/TwoPortReceive)!
I am using an arduino ethernet. The devices I am trying to get data from include a GPS and an IMU both from sparkfun.
I can get data from either devices using just on software serial port but as soon as I add the second software serial port, neither ports will work. I can't use the hardware serial port because that is being used byt another device.
My code is exactly similar to the example:
#include <SoftwareSerial.h>
SoftwareSerial portOne(7,8);
SoftwareSerial portTwo(5,6);
void setup()
{
Serial.begin(9600);
portOne.begin(9600);
portTwo.begin(9600);
}
void loop()
{
portOne.listen();
while (portOne.available() > 0) {
char inByte = portOne.read();
Serial.write(inByte);
}
delay(500);
portTwo.listen();
while (portTwo.available() > 0) {
char inByte = portTwo.read();
Serial.write(inByte);
}
Serial.println();
}
Anyone with any ideas?
This code will not work, or will work poorly if it works at all. SoftwareSerial only has one internal buffer. Yes, you can have multiple SoftwareSerial objects in existence, but only one of them controls the internal buffer. When any RX pin gets asserted, that generates an interrupt, but only the listen()ing RX pin gets checked for a start bit.
What's really needed is the ability to check on multiple pins when an interrupt comes along from the start bit. Then you'd have to set up pointers to the appropriate data structures. It would be complicated, but possible.
Or maybe just give up on interrupt-driven reception, and spin on checking both/all of the RX pins, and start the receive based on the pin you see. Be forwarned that this code has much hair, and you WILL need an oscilloscope to make it work.
I'm having a similar problem, which is why I found your sensor. After talking it over with my co-workers, we've decided to read our sensors in rotating order. Our sensors report the current state of the sensor, and not specific events, so it's okay if we lose some reports. So we'll read from port 1, then read from port 2, then port 1, etc. Our sensors spit out lines of text, so we know when to switch to the next sensor.
The referenced example only actively listens to one port at a time. The recommended solution would be to upgrade to an Arduino Mega (https://www.sparkfun.com/products/11061) which has 4 hardware serial ports.
In order to simultaneously support two software serial ports is going to require a lot of the CPU resources. It also be a difficult design and excessive programming time far outweighing the cost of $58 + shipping.
Looking at you code again it occurs to me that you are immediately checking for characters after your portOne.listen command. At 9600 baud it will take approximately 1ms for the first character to arrive, your while test will have been completed and the portTwo.listen command executed long before the first character arrives.
For testing purposes try adding a 1-2 ms delay after the portOne.listen command and see if you get a character.
As an example (untested and note, if port one is sending characters with no intercharacter gaps, the first while will never fail, preventing reading portTwo characters):
void loop()
{
portOne.listen();
delay(2);
while (portOne.available() > 0) {
char inByte = portOne.read();
Serial.write(inByte);
delay(1);
}
portTwo.listen();
delay(2);
while (portTwo.available() > 0) {
char inByte = portTwo.read();
Serial.write(inByte);
delay(1);
}
Serial.println();
}
Don't use while ......
Use:
{ portOne.listen();
if (PortOne.available() ) {
ricevo = myPort1.read(); }
// delay(2); // ridiculos waiting time
// delay(1); // extra ridiculos waiting time
Than 500 ms is a too big time for switching, no time.....