如何写动态文本到LED显示屏串行w/ Arduino

所以我想我接近了，但是我遇到了瓶颈。这是我想要完成的:我有一个计算点击次数的程序，并且在值更新时将串行数据发送到Arduino (UNO)。

到目前为止，我有以下工作:- LED显示屏上的滚动字幕(来自Freetronics - http://www.freetronics.com/products/dot-matrix-display-32x16-red#.UOBeKInjmdM)Python脚本通过Serial(使用PySerial)向Arduino写入新数据- Arduino是正确地接收串行监视器中的数据…

所以我的问题是我不能让它写到LED显示屏，请帮助!

下面是我的代码:

import serial
import argparse
myserial = serial.Serial('/dev/tty.usbmodemfd121', 9600)
parser = argparse.ArgumentParser(description='Example with non-optional arguments')
parser.add_argument('count', action="store", type=str)
results = parser.parse_args()
count = results.count
message = "total clicks: " + count
print message
myserial.write(message)

例子:$ python app.py 200这将发送"total clicks: 200"到Arduino

这是我的Arduino草图:

/*
  Scrolling text demonstration sketch for Freetronics DMD.
 See http://www.freetronics.com/dmd for resources and a getting started guide.
 Note that the DMD library uses the SPI port for the fastest, low overhead writing to the
 display. Keep an eye on conflicts if there are any other devices running from the same
 SPI port, and that the chip select on those devices is correctly set to be inactive
 when the DMD is being written to.  
 */
// you always need the code from here...........
#include <DMD.h> // for DMD
#include <SPI.h> // SPI.h must be included as DMD is written by SPI (the IDE complains otherwise)
#include <TimerOne.h> 
#include "SystemFont5x7.h"
#include "Arial_black_16.h"
#include "Arial_14.h"
#define DISPLAYS_ACROSS 1 // change to 2 for two screens, etc. 
#define DISPLAYS_DOWN 1
DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN); // creates instance of DMD to refer to in sketch
char message[] = "test string to be updated";
char serIn; //var that will hold the bytes in read from the serialBuffer
void ScanDMD() // necessary interrupt handler for refresh scanning of DMD
{ 
  dmd.scanDisplayBySPI();
}
void setup()
{
   //initialize TimerOne's interrupt/CPU usage used to scan and refresh the display
   Timer1.initialize( 5000 );           //period in microseconds to call ScanDMD. Anything longer than 5000 (5ms) and you can see flicker.
   Timer1.attachInterrupt( ScanDMD );   //attach the Timer1 interrupt to ScanDMD which goes to dmd.scanDisplayBySPI()  
   dmd.clearScreen( true );   //true is normal (all pixels off), false is negative (all pixels on)
   Serial.begin(9600);
}
void loop()
{
// only if there are bytes in the serial buffer execute the following code
if(Serial.available()) {    
  //keep reading and printing from serial untill there are bytes in the serial buffer
   while (Serial.available()>0){
      serIn = Serial.read();    //read Serial   
       Serial.write( byte(serIn));
   }
   //the serial buffer is over just go to the line (or pass your favorite stop char)               
   Serial.println();
}
   // Now I want to write the Serial message ti the DMD Disply
  dmd.selectFont(Arial_Black_16);
  // the text in the quotes in the next line will be scrolled across the display(s).
  // message writes the TEST message above, but I want it to write serIn variable (serial data)
  dmd.drawMarquee(message,strlen(message),(32*DISPLAYS_ACROSS)-1,0);
  // THIS IS WHAT I WANT, but I get this error "invalid conversion from 'char' to 'const char*'"
  //dmd.drawMarquee(serIn,strlen(serIn),(32*DISPLAYS_ACROSS)-1,0);
  long start=millis();
  long timer=start;
  boolean ret=false;
  while(!ret){
    if ((timer+30) < millis()) {
      ret=dmd.stepMarquee(-1,0);
      timer=millis();
    }
  }     
  delay(100);
}

我一直遇到的错误是dmd.drawMarquee()将第一个参数作为字符串，我对c++一无所知，所以我认为我搞砸了数据类型。