I have done this on purpose. I wanted to show you how the Arduino reads numbers from the com port, and how easy it is to exclude vital functionality in your code.
I have kept this script simple, however, if you wanted to, you could make the Arduino deal with each of the above situations and more. Multiplication, division and subtraction is handled in the same way. This is the last thing I want you to try before we go to the next stage: 6. Enter this sequence: +1= Result: +1= +1= Result: +1= - Note that the maximum size of a 'long' number is. If you add one to this number, the result is equal to the minimum size of a 'long' which is. STAGE 4: Sending doubles to Arduino: The double doubler.
The blue text represents the string (or array of characters) being sent using lines 19 and 21. The red text represents the actual double being sent using lines 20 and 22. You will notice that myDub2 rounds to 2.00. This may or may not be what you want.
Arduino Playground - Interfacing. You have come to the place to learn about connecting an Arduino to other devices, whatever software is running on. Since I had some problems looking for information about how to communicate the Arduino's board with the computer. Arduino USB Communication. Learn how to interface arduino through serial communication with python using the pyduino library. There are few other tutorials out there on instructables on how to.
If you wish to increase the number of decimal places, then you will need to change lines 20 and 22 to the following: 20 Serial.println(myDub1, 4 ); 22 Serial.println(myDub2, 4 ); The number 4 highlighted in red, indicates the number of decimal places you wish to send. And try changing this number to something bigger or smaller. --------------------------------------------------------------------------------------------------- Ok - now that we understand this little Serial.print(double,decimals) trick, we will now get the Arduino to echo back a Double. Before we jump in, perhaps we should try and map out our strategy. For this we will choose a simple decimal to make it easier. So in this example, we will choose 0.1. STAGE 5: Sending sensor data to the Serial Monitor We know the Arduino is very good at copy-Cat games, how about getting the Arduino to send us some data from one of our sensors.
We will use the Serial Monitor to view the sensor data. Disconnect the USB cable, and hook up one of your favourite analog sensors to your Arduino.
For simplicity, I am going to hook up a potentiometer as per the Fritzing sketch below. Parts Required • Arduino UNO (or equivalent) • Computer with USB cable • Breadboard • Potentiometer • 3 Wires. Hi Anonymous, Please note the difference between Serial.write() and Serial.print(). See stage 4 of this tutorial on how to send a value such as 1.456 from the Arduino to the Serial Monitor. Once you get this part working, then you can work on the other half of your project, which would be the task of getting Simulink to listen for Serial data.
If you wanted to send 1.456 through using Serial.write, then I would write the code like this: Serial.write(49); Serial.write(46); Serial.write(52); Serial.write(53); Serial.write(54); Serial.println(); You may want to look at the ASCII table as to how I got those numbers. I'll give you a hint: When you write 49, it sends through a 1 If you choose to send through the value using Serial.print(): I would send it through like this: Serial.println(1.456, 3); If you write it like this: Serial.println(1.456); then it will only send to the default 2 decimal places which is 1.46 Hope this helps Scott. Anonymous Thanks for your answer, Scott C! I understand that I can send different types of data depending on using.write or print. On simulink I have a block that strictly needs his input data to be bytes, that is the reason I am using Serial.write. In that Simulink block, I can choose how the data can be shown (double, single, int8, unint8.).
My problem is that just int8 or unint8 works. Once I select 'double' or 'single', the data obtained is not correct.
I assume that the problem remains on the sender, the arduino, and consequently Serial.write. Then, once I use Serial.write(1.456),theorically the receiver should or should not be able to obtain 1.456 again?
Thanks for your effort! Anonymous Thanks for your help Scott, The block I am using does not understand about strings I guess. In simulink you are able to select the data that is receiving, that is: int8,int16,int32, single and double. You can select the 'parity' too, which I selected 'none' (from: none, even, odd, mark or space), is that correct? And, I also can select 'byte order' between bigEndian or LittleEndian (I have BigEndian but I do not know the difference). I am thinking about sending a byte of the integer of the float and a byte of the 2 decimals of the float.
I will read this in simulink as two different numbers but once read I can play with them. I will try this. Keep you update, thanks for all your help! Hi Joseph, You have confused me a little, but that's ok. If you only want to have 2 inputs - with the first input replicated 4 times, but with the last input independent from the first 4 numbers, then you have coded this properly. I would eliminate the Serial.write(enternumber); line. And just type 1+1= into the serial monitor.
Download Step 3d Format Converter. This will give you the answer you want. If you want the output of 3+3+3+3+5=17 as the ouput, then you would enter this into the Serial monitor: 3+5= However, if you actually want 5 independent inputs and get the arduino to calculate, then you have done it all wrong. Pay attention to 'myswitch' and what myswitch is actually there for. What is 'myswitch' actually doing?, and why do you need it in my original code? There lies your problem.
Regards ScottC. I want to have a computer send commands to my Arduino to start certain sequences - i.e., send a '1' via serial to start sequence A, send a '2' via serial to start sequence B, etc. For this device, the serial commands are replacing button presses, which I previously handled using interrupts. There should be at least a 1 second delay between each serial command, so using a short interrupt function (set buttonPressed = true, for example) shouldn't be a problem - i.e., I shouldn't be missing the next serial byte. I just can't figure out how to get a byte available on serial to trigger the interrupt routine. Anonymous Hello, i have a question.
I have a program which encodes a Number into serial commands and recieve serial commands to handle it as a input. Now i want to emulate the Hardware and sending a command to the software.
But i have no idea how it is coded (i am really a beginner). If i use your Echo programm, the software work well but if i send just the bits to the software i get errors. If i type in these to send: 30 00 01 02 00 07 00 I get this on the serial communication: 02 30 0A 20 0A 21 0A 22 0A 20 0A 27 0A 20 AE 03 So what do i have to send from Arduino to get these communication back? If i use Serial.write('02300A200A210A220A200A270A20AE03'); it dont work. Hope anybody can help me. Sami First of all, thanks a lot to the writer for this very useful post.
In my project, I'm trying to send some float type data with upto 2 digits after the decimal to a MYSQL server. I'm using Arduino Uno & Arduino Ethernet Shield, and I need to send the data with upto 4 digits after the decimal. I was really frustrated, but my the mercy of God, I came to read this post & found out that it's Arduino's nature. Most probably I shouldn't ask it here. But still, could the writer help me with a code solving my problem? Thanks in advance.
Sorry fro not being precise. But I was talking about sending binary data.
Serial.print(x, BIN); will send 8 bytes for one byte (0-255) value. So still ASCII format sending. For hex situation is a bit better but still 2 bytes instead of one. So if you want for example fast sending of ADC data just in 1 byte resolution, with ASCII you would need minimum 3 bytes per sample to send. 2 bytes of data + ` byte separator. And even one byte of separator will probably not be enough.
So it is much slower that just sending 1 byte per sample. For these situations I was referring to Sorry for confusion.
And there are also cool things there such as predefined strings for sending, from PC side and also scripting to automatically response from PC side on specific word received. So you can kind of make small PC processing program without all the hard coding in matter of seconds. There are definitely advantages for using a PC for some Serial communication tasks. There are many terminal programs on the internet that are specifically created for that task. There is actually no need for an Arduino for those purposes.
Just connect your computer directly. I think you managed to 'advertise' docklight in every one of your responses. The tutorial above shows how Serial communication works with an Arduino. If people are looking for Serial communication using a computer, then this is not the right tutorial for your needs.
Used for communication between the Arduino board and a computer or other devices. All Arduino boards have at least one serial port (also known as a UART or USART): Serial. It communicates on digital pins 0 (RX) and 1 (TX) as well as with the computer via USB. Thus, if you use these functions, you cannot also use pins 0 and 1 for digital input or output. You can use the Arduino environment’s built-in serial monitor to communicate with an Arduino board. Click the serial monitor button in the toolbar and select the same baud rate used in the call to begin(). The Arduino Mega has three additional serial ports: Serial1 on pins 19 (RX) and 18 (TX), Serial2 on pins 17 (RX) and 16 (TX), Serial3 on pins 15 (RX) and 14 (TX).
To use these pins to communicate with your personal computer, you will need an additional USB-to-serial adaptor, as they are not connected to the Mega’s USB-to-serial adaptor. To use them to communicate with an external TTL serial device, connect the TX pin to your device’s RX pin, the RX to your device’s TX pin, and the ground of your Mega to your device’s ground.