Serial Call and Response (handshaking) with ASCII-encoded output
This example demonstrates string-based communication from the Arduino board to the computer using a call-and-response (handshaking) method.
The sketch sends an ASCII string on startup and repeats that until it gets a serial response from the computer. Then it sends three sensor values as ASCII-encoded numbers, separated by commas and terminated by a linefeed and carriage return, and waits for another response from the computer.
You can use the Arduino Software (IDE) serial monitor to view the sent data, or it can be read by Processing (see code below), Flash, PD, Max/MSP (see example below), etc. The examples below split the incoming string on the commas and convert the string into numbers again.
Compare this to the Serial call and response example. They are similar, in that both use a handshaking method, but this one encodes the sensor readings as strings, while the other sends them as binary values. While sending as ASCII-encoded strings takes more bytes, it means you can easily send values larger than 255 for each sensor reading. It's also easier to read in a serial terminal program.
2 analog sensors (potentiometer, photocell, FSR, etc.)
3 10K ohm resistors
Connect analog sensors to analog input pin 0 and 1 with 10K ohm resistors used as voltage dividers. Connect a pushbutton or switch to digital I/O pin 2 with a 10K ohm resistor as a reference to ground.
Copy the Processing sketch from the code sample above. As you change the value of the analog sensor, you'll get a ball moving onscreen something like this. The ball will appear only when you push the button:
The max patch looks like this. Copy the text from the code sample above and paste it into a new Max window
ASCIITable - Demonstrates Arduino's advanced serial output functions.
Dimmer - Move the mouse to change the brightness of an LED.
Graph - Send data to the computer and graph it in Processing.
Midi - Send MIDI note messages serially.
MultiSerialMega - Use two of the serial ports available on the Arduino Mega.
PhysicalPixel - Turn a LED on and off by sending data to your board from Processing or Max/MSP.
ReadASCIIString - Parse a comma-separated string of integers to fade an LED.
SerialCallResponse - Send multiple variables using a call-and-response (handshaking) method.
SerialEvent - Demonstrates the use of serialEvent().
VirtualColorMixer - Send multiple variables from Arduino to your computer and read them in Processing or Max/MSP.
Last revision 2015/07/29 by SM