I have the code, it's purpose is to receive the string from a comport like: Set@1890156 and translate it into four byte arrays byte user1. Jul 06, 2015 Arduino MEGA 2560 and Due. Both the MEGA 2560 and Due have 4 serial ports in total. One that connects through a USB port chip to the USB device port on the board and three extra serial ports that connect to pins on one of the pin headers of the board.
Active2 years, 8 months ago
I'm using two Arduinos to sent plain text strings to each other using newsoftserial and an RF transceiver.
- Look up the C union structure. It allows you to define a data type which may be stored in one format, and read out in another. I use it all the time to move floats or other data non-byte types into an array of bytes, transfer the array as bytes via serial, and read out the results as floats.
- Prints data to the serial port as human-readable ASCII text. This command can take many forms. Numbers are printed using an ASCII character for each digit. Floats are similarly printed as ASCII digits, defaulting to two decimal places. Bytes are sent as a single character. Characters and strings are sent as is.
Each string is perhaps 20-30 characters in length. Gba4ios game download. How do I convert
Peter MortensenSerial.read()
into a string so I can do if x 'testing statements'
, etc.?14.5k1919 gold badges8989 silver badges118118 bronze badges
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15 Answers
Peter Mortensen14.5k1919 gold badges8989 silver badges118118 bronze badges
magmamagma7,61411 gold badge3030 silver badges3232 bronze badges
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You can use
Serial.readString()
and Serial.readStringUntil()
to parse strings from Serial on the Arduino.You can also use
Serial.parseInt()
to read integer values from serial.The value to send over serial would be
my stringn5
and the result would be str = 'my string'
and x = 5
![Serial Serial](https://www.arduino.cc/en/uploads/ArduinoStarterKit/prj14_2.jpg)
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Ihab HajjIhab Hajj1,54711 gold badge1515 silver badges3131 bronze badges
I was asking the same question myself and after some research I found something like that.
It works like a charm for me. I use it to remote control my Arduino.
ladislasladislas
mrvmrv
The best and most intuitive way is to use serialEvent() callback Arduino defines along with loop() and setup().
I've built a small library a while back that handles message reception, but never had time to opensource it.This library receives n terminated lines that represent a command and arbitrary payload, space-separated.You can tweak it to use your own protocol easily.
First of all, a library, SerialReciever.h:
To use it, in your project do this:
To use the received commands:
BlazerBlazer
If you want to read messages from the serial port and you need to deal with every single message separately I suggest separating messages into parts using a separator like this:
This way you will get a single message every time you use the function.
QurashiQurashi
Here is a more robust implementation that handles abnormal input and race conditions.
- It detects unusually long input values and safely discards them. For example, if the source had an error and generated input without the expected terminator; or was malicious.
- It ensures the string value is always null terminated (even when buffer size is completely filled).
- It waits until the complete value is captured. For example, transmission delays could cause Serial.available() to return zero before the rest of the value finishes arriving.
- Does not skip values when multiple values arrive quicker than they can be processed (subject to the limitations of the serial input buffer).
- Can handle values that are a prefix of another value (e.g. 'abc' and 'abcd' can both be read in).
It deliberately uses character arrays instead of the
String
type, to be more efficient and to avoid memory problems. It also avoids using the readStringUntil()
function, to not timeout before the input arrives.The original question did not say how the variable length strings are defined, but I'll assume they are terminated by a single newline character - which turns this into a line reading problem.
Here is an example of it being used to read commands from the serial monitor:
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flamaniacflamaniac
If you're using concatenate method then don't forget to trim the string if you're working with if else method.
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user3528736user3528736
Use string append operator on the serial.read(). It works better than string.concat()
After you are done saving the stream in a string(mystring, in this case), use SubString functions to extract what you are looking for.
SaroshSarosh
Credit for this goes to magma. Great answer, but here it is using c++ style strings instead of c style strings. Some users may find that easier.
j_v_wow_dj_v_wow_d
BengtBengt10.4k55 gold badges3939 silver badges6161 bronze badges
Many great answers, here is my 2 cents with exact functionality as requested in the question.
Plus it should be a bit easier to read and debug.
Code is tested up to 128 chars of input.
Tested on Arduino uno r3 (Arduino IDE 1.6.8)
Functionality:
Arduino Byte Serial Print
- Turns Arduino onboard led (pin 13) on or off using serial command input.
Commands:
- LED.ON
- LED.OFF
Note: Remember to change baud rate based on your board speed.
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TheJonaMrTheJonaMr
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Active6 years, 1 month ago
I am beginer in programming, and I need some help to read 2 bytes (msb/lsb) that comes after a request (0x01 to msb and 0x02 to lsb) via serial, and then, make an mathematical operation and display on an 2x16 display. I have the functions of my project that use only 1 byte working good. One example:
regards. Adesso scanner drivers.
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marvmarv
2 Answers
Wait until the Serial buffer has two bytes, then read them:
This code is blocking so you may want to change from a while loop to a delay and some if statements. Also I'm not sure if your LCD prints MSB or LSB first, I assumed MSB.
user2461391user2461391
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