Introduction

To simplify the viewing of changing data, we created this library of functions to simulate panel meters on your screen. It is based on pygame which is preinstalled on the Raspian OS so no additional software has to be installed.

What You'll Need

1. A connection to your Raspberry Pi - either through a monitor and keyboard or remotely with VNC
2. Optional - a TINKERplate connected to a programmed Raspberry Pi

Steps

Example 1 - Simple Meter

1. Open the Thonny Python IDE under the Raspberry Icon:
   
2. Enter the code as ahown below - you don't have to type all the stuff after the hashtags (#)
   
3. If you have typed everything correctly, click on the green GO button should produce this window with changing data on your screen:
   
4. Here's the code again if you prefer to simply paste it into your editor:
   
   METER Demo 1

   Python

   import piplates.TINKERplate as TINK #import TIINKERplate module import math #import math module - needed for sine and pi import time #import the time module - needed for sleep Mag=10 N=360 TINK.openMETER() #create a panel meter with the default of a single line while(True): #Loop forever for i in range(N): #do this 360 times val=Mag*math.sin(2*math.pi*i/360) #calculate the sine value TINK.setMETER(val,'volts','Sine Data:') #send data to the meter time.sleep(0.05) #pause for 50msec

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   import piplates.TINKERplate as TINK  #import TIINKERplate module import math #import math module - needed for sine and pi import time #import the time module - needed for sleep   Mag=10 N=360 TINK.openMETER()    #create a panel meter with the default of a single line while(True):        #Loop forever     for i in range(N):   #do this 360 times         val=Mag*math.sin(2*math.pi*i/360)       #calculate the sine value           TINK.setMETER(val,'volts','Sine Data:') #send data to the meter         time.sleep(0.05)                        #pause for 50msec

   The above code can be downloaded from github by typing the following instructions on the command line:
   1. git clone https://github.com/pi-plates/TINKERplate-Projects.git
   2. cd TINKERplate-Projects
   3. python3 SimpleMeter.py

Example 2 - Four Meters

1. Either modify your existing code or enter this new example from scratch
2. Write and save the code as shown below and don't worry about all the comments (the stuff after the hashtags)
   
3. Again if you have typed everything correctly, click on the green GO button should produce this new window with changing data on your screen:
   
   Note that we have four lines of data now, bright yellow text, and a title for our window.
4. Here's the code again with more comments if you simply want to paste it into your program:
   
   METER demo 2

   Python

   import piplates.TINKERPlate as TINK #import TINKERplate module import math #import math module - needed for sine and pi import time #import the time module - needed for sleep Mag=10 N=360 mColor=(255,255,0) #this tuple represents the color yellow TINK.openMETER(4) #create a panel meter with the default of a single line TINK.setCOLOR(mColor) #set meter color TINK.setTITLE('Trigonometery Functions') #Set meter title while(True): #Loop forever for i in range(N): #do this 360 times TINK.setMETER(i,'degrees','Angle:',1) #write angle to line 1 val=math.sin(2*math.pi*i/360) #calculate sine of angle TINK.setMETER(val,'','Sine:',2) #write sine value to line 2 val=math.cos(2*math.pi*i/360) #calculate cosine of angle TINK.setMETER(val,'','Cosine:',3) #write cosine value to line 3 val=math.tan(2*math.pi*i/360) #calculate tangent of angle TINK.setMETER(val,'','Tangent:',4) #write tangent value to line 4 time.sleep(0.1)

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   import piplates.TINKERPlate as TINK  #import TINKERplate module import math  #import math module - needed for sine and pi import time  #import the time module - needed for sleep   Mag=10 N=360 mColor=(255,255,0) #this tuple represents the color yellow TINK.openMETER(4)  #create a panel meter with the default of a single line TINK.setCOLOR(mColor)   #set meter color TINK.setTITLE('Trigonometery Functions')    #Set meter title while(True):  #Loop forever     for i in range(N):   #do this 360 times         TINK.setMETER(i,'degrees','Angle:',1)   #write angle to line 1         val=math.sin(2*math.pi*i/360)           #calculate sine of angle         TINK.setMETER(val,'','Sine:',2)         #write sine value to line 2         val=math.cos(2*math.pi*i/360)           #calculate cosine of angle         TINK.setMETER(val,'','Cosine:',3)       #write cosine value to line 3         val=math.tan(2*math.pi*i/360)           #calculate tangent of angle         TINK.setMETER(val,'','Tangent:',4)      #write tangent value to line 4                 time.sleep(0.1)

The above code can be downloaded from github by typing the following instructions on the command line:

1. git clone https://github.com/pi-plates/TINKERplate-Projects.git
2. cd TINKERplate-Projects
3. python3 FourMeters.py