cpudail.py

import serial
import time
import subprocess

def scale(toscale, fromr=[-1,1],tor=[0,100],invert=0):#scale any number in one range to another
    #linier only right now. uses y=mx+b
    x1=fromr[0]
    x2=fromr[1]
    y1=tor[0]
    y2=tor[1]
    m=((y2-y1)/(x2-x1))
    b=((-m)*x1+y1)
    ret=(m*toscale+b)
    if invert ==1:
        #((self.ax * -1) + 100)
        
        ret=((ret*-1)+tor[1])
    return ret

CMD=['mpstat', '1', '1']
def getcpu():
    cpu=subprocess.Popen(CMD,stdout=subprocess.PIPE).stdout.read().split('\n')[-2].split()[2]
    
    return float(cpu)
    
    
def main():
    ard=serial.Serial('/dev/ttyUSB0')
    ard.write('g')#g for go!
    ard.flushInput()#got to clear the stream that started at the arduino
    while True:
        time.sleep(0.25)#got to give servo chance to move
        f=getcpu()
        full=scale(f,[0.0,100.0],[0,255],1)
        print full,f
        
        ard.write(chr(int(full)))
    
if __name__=='__main__':
    main()

simple program to read and set my cpu dail