Arduino-处理以保存和显示数据 [英] Arduino - Processing to save and display the data
问题描述
我的Arduino的代码:
#include<EngduinoThermistor.h>
void setup()
{
Serial.begin(9600);
EngduinoThermistor.begin();
}void loop()
{
float temp;
temp = EngduinoThermistor.temperature();
Serial.println(temp);
delay(1000);
}
我的处理代码:
import processing.serial.*;
Serial port;
float x = 0;
void setup() {
size(500, 400);
println(Serial.list());
String portName = Serial.list()[0];
port = new Serial(this, "/dev/tty.usbmodem1411", 9600);
}
void draw() {
}
void serialEvent(Serial port) {
float inByte = port.read();
println(inByte);
stroke(90, 76, 99);
line(x, height, x, height - inByte);
if (x >=width) {
x=0;
background(200);
}
x++;
}
我非常努力地理解处理过程，但是我仍然不明白如何根据arduino发送的数据绘制图形.我认为我主要遇到的问题是线路部分.我不知道如何画一条连接上一点和新点的线.
但是总的来说，这个问题甚至无法解决....问题出在哪里:(??
根据 bufferUntil()函数结合使用时，这实际上很有用./p>
主要缺少的成分实际上是从接收到的String中解析float.
这是一个基本的转换示例:
String temperatureString = "37.5";
float temperatureFloat = float(temperatureString);
您可以使用Serial的 readString()来获取字符串，然后 trim()删除空格，然后最终将其转换为浮点数:
temperature = float(port.readString().trim());
检查转换是否成功也是一个好主意:
if(!Float.isNaN(temperature)){
println("read temperature",temperature);
x++;
}
总的来说，检查错误是个好主意，因此，这是一个执行上述操作并同时检查串行端口和注释的版本:
import processing.serial.*;
//serial port
Serial port;
//x position of current value on graph
float x = 0;
//current temperature reading
float temperature;
void setup() {
size(500, 400);
background(200);
String[] portNames = Serial.list();
println(portNames);
String portName = "not found";
//loop through available serial ports and look for an Arduino (on OSX something like /dev/tty.usbmodem1411)
for(int i = 0 ; i < portNames.length; i++){
if(portNames[i].contains("tty.usbmodem")){
portName = portNames[i];
break;
}
}
//try to open the serial port
try{
port = new Serial(this, portName, 9600);
//buffer until new line character (since values are send via println() from Arduino)
port.bufferUntil('\n');
}catch(Exception e){
System.err.println("Arduino port " + portName);
e.printStackTrace();
}
}
void draw() {
//draw graph
stroke(90, 76, 99);
//you might want to map the temperature to sketch dimensions)
line(x, height, x, height - temperature);
if (x >=width) {
x=0;
background(200);
}
}
void serialEvent(Serial port) {
try{
//read the string, trim it (in case there's a '\n' character), then convert it to a float
temperature = float(port.readString().trim());
//check if the float conversion was successfull (didn't get a NaN value)
if(!Float.isNaN(temperature)){
println("read temperature",temperature);
x++;
}
}catch(Exception e){
System.err.println("error parsing value from serial port");
e.printStackTrace();
}
}
Code for my Arduino:
#include<EngduinoThermistor.h>
void setup()
{
Serial.begin(9600);
EngduinoThermistor.begin();
}void loop()
{
float temp;
temp = EngduinoThermistor.temperature();
Serial.println(temp);
delay(1000);
}
Code for my Processing:
import processing.serial.*;
Serial port;
float x = 0;
void setup() {
size(500, 400);
println(Serial.list());
String portName = Serial.list()[0];
port = new Serial(this, "/dev/tty.usbmodem1411", 9600);
}
void draw() {
}
void serialEvent(Serial port) {
float inByte = port.read();
println(inByte);
stroke(90, 76, 99);
line(x, height, x, height - inByte);
if (x >=width) {
x=0;
background(200);
}
x++;
}
I have tried really hard to understand processing but I still don't understand how to draw a graph based on the data sent by the arduino. I think the problem that I have mostly is the line part. I don't know how to draw a line connecting the previous point and the new point.
But overall the problem does not even work.... Where is the problem :( ?
According to the Engduino Thermistor Documentation (pdf link), the value is a float.
Because you're sending the value using println(), there is a new line character ('\n') sent along with the floating point value. This can actually be useful in conjuction with Processing Serial's bufferUntil() function.
The main missing ingredient is actually parsing a float from the received String.
Here's a basic conversion example:
String temperatureString = "37.5";
float temperatureFloat = float(temperatureString);
You can use Serial's readString() to get the string, then trim() it to remove whitespace, then finally convert it to a float:
temperature = float(port.readString().trim());
It's also a good idea to check if the conversion was successful:
if(!Float.isNaN(temperature)){
println("read temperature",temperature);
x++;
}
Overall it's a good idea to check for errors, so here's a version that does the above and checks the serial ports as well and comments:
import processing.serial.*;
//serial port
Serial port;
//x position of current value on graph
float x = 0;
//current temperature reading
float temperature;
void setup() {
size(500, 400);
background(200);
String[] portNames = Serial.list();
println(portNames);
String portName = "not found";
//loop through available serial ports and look for an Arduino (on OSX something like /dev/tty.usbmodem1411)
for(int i = 0 ; i < portNames.length; i++){
if(portNames[i].contains("tty.usbmodem")){
portName = portNames[i];
break;
}
}
//try to open the serial port
try{
port = new Serial(this, portName, 9600);
//buffer until new line character (since values are send via println() from Arduino)
port.bufferUntil('\n');
}catch(Exception e){
System.err.println("Arduino port " + portName);
e.printStackTrace();
}
}
void draw() {
//draw graph
stroke(90, 76, 99);
//you might want to map the temperature to sketch dimensions)
line(x, height, x, height - temperature);
if (x >=width) {
x=0;
background(200);
}
}
void serialEvent(Serial port) {
try{
//read the string, trim it (in case there's a '\n' character), then convert it to a float
temperature = float(port.readString().trim());
//check if the float conversion was successfull (didn't get a NaN value)
if(!Float.isNaN(temperature)){
println("read temperature",temperature);
x++;
}
}catch(Exception e){
System.err.println("error parsing value from serial port");
e.printStackTrace();
}
}
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