I'm trying to write a program in C# to communicate with my Arduino UNO from my computer via a serial connection. At the moment I'm just writing a simple application that establishes contact with the Arduino, and then with several controls to control each pin on the arduino; either read a value from it or write a value to it.
I've managed to establish contact with the Arduino and to set pin-values, but it doesn't always want to obey my commands. I set up a few check boxes, and when I check a box, an LED should turn on, and off when I un-check it. The problem is that sometimes the LED's just stay on or off and I have to click the box a few times before it responds again, or reset my circuit...
I was trying to do some fault-finding, but couldn't get to the root of the problem: is it my app or is it the Arduino code?
Here are the relevant pieces of my code:
private void sendValue(int RW, int _Pin, int Val) //send from my app to serial port
{
if (CommPort.IsOpen)
{
CommPort.WriteLine(RW.ToString() + "," + _Pin.ToString() + "," + Val.ToString());
}
}
private void chP9_CheckedChanged(object sender, EventArgs e) //call the sendValue routine
{
if (chP9.Checked)
{
sendValue(1, 9, 255); //('Write', to pin 9, 'On')
}
else
{
sendValue(1, 9, 0); //('Write', to pin 9, 'Off')
}
}
This is my C# code, it compiles a comma-delimited string to send over the serial port to be read by the Arduino.
Here's the Arduino code:
int RW; //0 to read pin, 1 to write to pin
int PN; //Pin number to read or write
int Val; //Value to write to pin
void setup() {
Serial.begin(38400);
}
void loop() {
ReadIncoming();
ProcessIncoming();
}
void ReadIncoming()
{
if(Serial.available() > 0)
{
RW = Serial.parseInt();
PN = Serial.parseInt();
Val = Serial.parseInt();
}
while(Serial.available() > 0) //Clear the buffer if any data remains after reading
{
Serial.read();
}
}
void ProcessIncoming()
{
if(RW == 0)
{
pinMode(PN, INPUT);
}
else
{
pinMode(PN, OUTPUT);
analogWrite(PN, Val);
}
}
parseInt just takes out the first integer value it finds, stores it and throws away the comma, and does it again and again, but it seems a bit counter-intuitive.
I think my problem lies here:
while(Serial.available() > 0) //Clear the buffer if any data remains after reading
{
Serial.read();
}
I think the App is sending data faster than the Arduino code could handle, especially with this loop, but what do I do with excess data?
I don't like to use the parseInt, but it's the only way I could find to read my instructions correctly. How do I send a byte array from C# and read that array into an array in Arduino?
I've pointed out my hypotheses, and explored alternatives but couldn't get any solutions. What suggestions do you guys have for me?
It is not that clear to me why it works at all. You ought to consider a smarter way to encode the command. You need only three bytes:
private void sendValue(int RW, int _Pin, int Val) {
var cmd = new byte[] { (byte)RW, (byte)_Pin, (byte)Val };
ComPort.Write(cmd, 0, cmd.Length);
}
Then you just need to read those 3 bytes on the Arduino end:
void ReadIncoming() {
if (Serial.available() >= 3) {
RW = Serial.read();
PN = Serial.read();
Val = Serial.read();
ProcessIncoming();
}
}
Related
I'm making a C# Win forms app that reads data from an arduino over serial port, parses it and displays it in a textbox.
My problem is that the value in the textbox is always a few seconds older than the value being sent by arduino even if I slow down the arduino to send the data once per second.
I know the problem must be in my C# code because when I read the serial port using a serial monitor everything's fine.
my code:
private void DataReceivedHandler(object sender, SerialDataReceivedEventArgs e)
{
string msgType;
string serialMsg;
serialMsg = port.ReadLine();
if(serialMsg.Substring(0, 1) != "#")
{
return;
}
msgType = serialMsg.Substring(1, 4);
if(msgType == "VOLT") // recieve supply voltage reading
{
textBox1.Invoke((MethodInvoker)delegate { textBox1.Text = serialMsg.Substring(5, serialMsg.Length - 5); });
}
if (msgType == "AMPS") // recieve supply current reading
{
textBox2.Invoke((MethodInvoker)delegate { textBox2.Text = serialMsg.Substring(5, serialMsg.Length - 5); });
}
if (msgType == "LOAD") // recieve load current reading
{
textBox3.Invoke((MethodInvoker)delegate { textBox3.Text = serialMsg.Substring(5, serialMsg.Length - 5); });
}
}
The messages coming from the arduino are in this format: # + TYPE + DATA
Can you tell me what's slowing it down?
I was sending the messages from the arduino too quickly so I put a 50ms delay between them
I also used ReadExisting instead of ReadLine
This solved all the lagging
I'm trying to figure out, what and how can get as unique identification number or any other kind of ID equivalent from particular Arduino Uno micro-controller from C# desktop application with serial port data
In case of Uno, I have COM3 open:
myport.PortName = comPort;
myport.BaudRate = 9600;
myport.Open();
But I'm not sure, how to read such data as ID of chip, for example with EEPROM Get :
#include <EEPROM.h>
void setup() {
float f = 0.00f;
int eeAddress = 0;
Serial.begin(9600);
while (!Serial) {
}
Serial.print("Read float from EEPROM: ");
EEPROM.get(eeAddress, f);
Serial.println(f, 3);
secondTest(); //Run the next test.
}
struct MyObject {
float field1;
byte field2;
char name[10];
};
void secondTest() {
int eeAddress = sizeof(float);
MyObject customVar;
EEPROM.get(eeAddress, customVar);
Serial.println("Read custom object from EEPROM: ");
Serial.println(customVar.field1);
Serial.println(customVar.field2);
Serial.println(customVar.name);
}
void loop() {}
and C#:
private void button1_Click(object sender, EventArgs e)
{
textBox1.Text = myport.ReadExisting();
}
I get some completely misunderstood result:
Read float from EEPROM: ovf
Read custom object from EEPROM:
ovf
95
_^^]]]\\\\fedc
What must be the output variable to get unique id from particular micro-controller:
Serial.println(customVar.field2);
Serial.println(customVar.name);
Atmega328P used in official Arduino UNO does not have any factory-programmed unique ID. However, Atmega328PB does have 10 bytes long preprogrammed serial number.
Atmega328PB seems to be quite compatible with Atmega328P. Differences are described in this application note: http://ww1.microchip.com/downloads/en/AppNotes/Atmel-42559-Differences-between-ATmega328P-and-ATmega328PB_ApplicationNote_AT15007.pdf
You can read serial number with boot_signature_byte_get() function from avr/boot.h: https://www.nongnu.org/avr-libc/user-manual/group__avr__boot.html#gaf375d2543ba38dc56697b4f4bc37a717
There are boards available with Atmega328PB chip, just google for "Atmega328PB arduino".
In case you cannot change the chip, then you would need to generate and program unique ID into your chip yourself.
My goal is pretty simple: I wanna read information from my RadioLink R12DS receiver by S-BUS protocol using desktop console application, written on C#.
I use AT9S transmitter blinded together with receiver in 12 channel mode. I tested it on Pixhawk flight controller. Everything was fine there, no any problem with retrieving data.
I designed a console application based on investigated articles. Here is a couple most valuable of them:
http://forum.fpv.kz/topic/303-frsky-x8r-sbus-v-cppm-konverter-na-arduino/ https://github.com/bolderflight/SBUS
My application receiving byte stream from a COM Port, one by one, and tries catch message header "0x0F", but it doesn't appear.
The SBUS protocol uses inverted serial logic with a baud rate of 100000, 8 data bits, even parity bit, and 2 stop bits. The SBUS packet is 25 bytes long consisting of:
Byte[0]: SBUS Header, 0x0F
Byte[1-22]: 16 servo channels, 11 bits per servo channel
Byte[23]:
Bit 7: digital channel 17 (0x80)
Bit 6: digital channel 18 (0x40)
Bit 5: frame lost (0x20)
Bit 4: failsafe activated (0x10)
Bit 0 - 3: n/a
Byte[24]: SBUS End Byte, 0x00
A table mapping bytes[1-22] to servo channels is included.
Here is listing of my code:
static void Main(String[] args)
{
var availablePorts = SerialPort.GetPortNames();
using(var port = new SerialPort(availablePorts[0], 100000, Parity.Even, 8, StopBits.Two))
{
port.DataReceived += PortOnDataReceived;
while(true)
{
if(!port.IsOpen)
TryReconnect(port);
Thread.Sleep(1000);
}
}
}
// HANDLERS ///////////////////////////////////////////////////////////////////////////////
private static void PortOnDataReceived(Object sender, SerialDataReceivedEventArgs serialDataReceivedEventArgs)
{
var serialPort = (SerialPort)sender;
if(SbusConverter.TryReadMessage(serialPort, out var messageBuffer))
{
var message = SbusConverter.Convert(messageBuffer);
Console.WriteLine(message.ServoChannels[0]);
}
}
public static Boolean TryReadMessage(SerialPort serialPort, out Byte[] messageBuffer)
{
const Int32 messageLength = 25;
const Int32 endOfStream = -1;
const Byte sBusMessageHeader = 0x0f;
const Byte sBusMessageEndByte = 0x00;
messageBuffer = new Byte[messageLength];
if(serialPort.BytesToRead < messageLength)
return false;
do
{
var value = serialPort.ReadByte();
if(value == endOfStream)
return false;
if(value == sBusMessageHeader)
{
messageBuffer[0] = (Byte)value;
for(var i = 1; i < messageLength; i++)
{
messageBuffer[i] = (Byte)serialPort.ReadByte();
}
if(messageBuffer[0] == sBusMessageHeader &&
messageBuffer[24] == sBusMessageEndByte)
return true;
}
} while(serialPort.BytesToRead > 0);
return false;
}
I have thoughts in my head and I want ask one question here.
It's possible, that RadioLink use different, modified or their own S-BUS implementation, than Futaba and I found no proper documentation yet.
Anybody, who experienced in that field, any suggestions please. It seems, I am stuck.
Thank you!
I made some investigations of received data stream and uncovered that RadioLink devices uses "0x1F" as a frame start byte insted of "0x0F". Another connection and message properties are the same.
var availablePorts = SerialPort.GetPortNames();
using(var port = new SerialPort(availablePorts[0], 100000, Parity.None, 8, StopBits.One)
{
Handshake = Handshake.None
})
{
port.DataReceived += PortOnDataReceived;
while(true)
{
if(!port.IsOpen)
OpenPort(port);
Thread.Sleep(1000);
}
}
Two years too late, but I just noticed you have 1 stop bit set, instead of 2, in the code of your answer. That could probably explain 0x1F instead 0x0F and otherwise shifted data.
I am trying to do the same kind of operation, intercepting Sbus signal from a herelink radio controller, so far I discovered a shift in the data and my start byte is recognised with the value of 0x1E. Moreover the data seems super noisy when looked at the oscilloscope, some 1 might be missing because of the poor quality of the signal and the ramp from 0 to 1.
I´d like to stream a text file containing G-Code to an Arduino UNO via the serialPort.
The Arduino receives all bytes with the SerialEvent and adds it to a char array named buffer. If the buffer is full it is supposed to send an "!;" over the serial port to C#.
This works fine as I have tested it with the Serial Montior application of the Arduino IDE. But I can´t type text as fast as C# can send it :)
The C# program reads the G-Code file linewise and then sends each char in a line to the arduino. After each char I want to check if the Arduino tells me if the buffer is full. Otherwise keep streaming.
Somehow c# never notices the "!;" or even gets any Bytes to read from the Arduino while streaming. I have the feeling that the serialPort.Write() function blocks the port.
This is the Arduino Code:
void serialEvent()
{
// wenn im Puffer noch platz ist
if (buffercount < MAX_BUF)
{
char c = (char)Serial.read();
buffer[buffercount++] = c;
}
else
{
Serial.print("!;");
}
}
The serialEvent is fired every time the Arduino receives bytes on the port.
Max_BUF has a value of 64.
This is the C# Code:
private void startStreaming(string Text)
{
string[] stringSeparators;
string Text2Stream;
if (Text == "")
{
Text2Stream = File.ReadAllText(textBoxSelectFile.Text);
stringSeparators = new string[] { "\n" };
}
else
{
stringSeparators = new string[] { "\r\n" };
Text2Stream = Text;
}
string[] t2s = Text2Stream.Split(stringSeparators, StringSplitOptions.None);
foreach (string zeile in t2s)
{
if (zeile.Contains(")") || zeile.Contains("("))
{
continue;
}
// Code schicken
foreach (char c in zeile)
{
if (c == ' ') continue;
serialPort.Write(c.ToString());
if (serialPort.BytesToRead > 0)
{
if(serialPort.ReadExisting() == "!;")
{
**wait and do smth.**
}
}
}
serialPort.Write(";");
addTextToLog(zeile);
}
}
serialPort.ReadExisiting() never happens because there are never BytesToRead.
The ";" is for both the sign for the end of a line.
startStreaming is started in an asynchronous thread as BackGroundWorker.
Somehow c# never notices the "!;" or even gets any Bytes to read from the Arduino while streaming. I have the feeling that the serialPort.Write() function blocks the port.
The Write command is not blocking the port. The arduino is just much slower then your computer. So between these two lines:
serialPort.Write(c.ToString());
if (serialPort.BytesToRead > 0)
the arduino is occupied and no data is received yet. Therefore BytesToRead is 0. Two possibilities to solve that come right away to my mind.
1) Use the serialPort.DataReceived event for asynchronous processing. This will be triggered every time you receive data. Then you can react upon the received data in that event or
2) Just give the arduino some time with System.Threading.Thread.Sleep(1000);
serialPort.Write(c.ToString());
System.Threading.Thread.Sleep(1000);
if (serialPort.BytesToRead > 0)
You need to find out which is the minimum timespan to wait.
I am currently working on a robotics project with Arduino. I want to access the serial port from different methods at different times.
For instance, I want to read the ADC at time t1 and get the motor currents at time t2. So I create readADC() and motorCurrents() methods which should both return int arrays of different sizes. The serial port data received is given below.
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
int n = serialPort1.BytesToRead;
serialPort1.Read(data, 0, data.Length);
}
I have implemented all the relevant coding on the Arduino side. I also have set the serial port. I need to implement the following commands in C#
private int[] ReadADC()
{
string input = "AN\n"; // This is the command for reading the ADC on the Wildthumper board.
serialPort1.Write(input);
// The Wildthumper now sends 11 bytes, the last of which is '*' and the first
// 10 bytes are the data that I want. I need to combine two bytes together
// from data received and make five values and return it.
for (int i = 0; i < 5; i++)
{
adcValues[i] = data[0 + i * 2] <<8+ data[1 + i * 2];
}
return adcValues;
// Where data is the bytes received on serial port;
}
Similarly:
private int[] getMotorCurrents()
{
string input = "MC\n"; // Wildthumper board command
serialPort1.Write(input);
// The Wildthumper now sends 5 bytes with the last one being '*'.
// And the first four bytes are the data that I want.
for (int i = 0; i < 2; i++)
{
MotorCurrents[i] = data[0 + i * 2] <<8 +data[1 + i * 2];
}
return MotorCurrents;
}
First of all, the number of bytes sent to me change. So how can I use a global variable? For data (the variable used to store serial data received as given above)?
You need to create a global variable and save the data to it when data received fires. This isn't hard.
Here is a code example:
public class myclass{
public string arduinoData = "";
private void serialPort1_DataReceived(
object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
this.arduinoData = serialPort1.ReadLine(data, 0, data.Length);
}
//....The rest of your code, such as main methods, etc...
}