Casio fx-CG100: The getkey command in Python
The getkey command: A Demonstration
The fx-CG100 adds a command to its Casioplot module, the beloved getkey command. The getkey returns the key code of the last key pressed from the command’s execution. The getkey allows for custom keyboard, movement of characters, or easy input of menu choices.
The getkey code that is assigned to each key on the fx-CG100 is thankfully fairly simple: it is a combination of the row number and a column number. For instance, the key code 21 is assigned to the [SETTINGS] key while the key code 95 is assigned to the [EXE] key.
Some key codes include:
Left arrow (←) |
23 |
Up arrow (↑) |
14 |
OK key |
24 |
Down arrow (↓) |
34 |
Right arrow (→) |
25 |
EXE |
95 |
1 Key |
81 |
2 Key |
82 |
3 Key |
83 |
4 Key |
71 |
5 Key |
72 |
6 Key |
73 |
7 Key |
61 |
8 Key |
62 |
9 Key |
63 |
0 Key |
91 |
Other key assignments can be found in the manual under the getkey() command in the Casioplot section: https://support.casio.com/global/en/calc/manual/fx-CG100_1AUGRAPH_en/BONDSYlkjdoxxc.html#BONDSYhxeuohnh
Note that the [ ON ] and [ AC ] buttons have no key assigned to them and can not be used with the getkey command.
Example: Calculating Horsepower
The script, hp.py calculates horsepower by one of three sets of inputs:
Press [ 1 ] to input weight (pounds) and time (seconds).
Press [ 2 ] to input weight (pounds) and speed (mi/hr).
Press [ 3 ] to input RPM (revolutions per minute) and torque (foot-pounds).
Using Getkey for Menus
To set up the getkey, I first make a “choice variable”, such as ch, and set it to 0. The while loop contains the menu and does not end until the user presses [ 1 ], [ 2 ], or [ 3 ] (or [ AC ] to terminate the program).
from casioplot import *
# setup
ch=0
# title screen
while ch==0:
clear_screen()
draw_string(0,0,"**HORSEPOWRER CALCULATOR**")
draw_string(0,20,"** Inputs Menu **")
draw_string(0,40,"1) weight, time",(192,0,0))
draw_string(0,60,"2) weight, speed",(0,0,192))
draw_string(0,80,"3) RPM, torque",(0,128,0))
show_screen()
k=getkey()
if k==81:
ch=1
elif k==82:
ch=2
elif k==83:
ch=3
# calculation
if ch==1:
w=float(input("weight in lbs: "))
t=float(input("time in sec: "))
hp=w*(t/5.825)**(-3)
elif ch==2:
w=float(input("weight in lbs: "))
s=float(input("speed in mph: "))
hp=w*(s/234)**3
elif ch==3:
r=float(input("RPM: "))
t=float(input("torque (ft-lbs): "))
hp=(r*t)/5252
clear_screen()
txt="{0:.5f} hp".format(hp)
draw_string(0,0,"Horsepower=")
draw_string(0,20,txt,(192,0,0))
draw_string(0,100,"Press AC to exit.",(0,128,128))
show_screen()
Notes: The getkey is meant to work with the Casioplot commands. Instead of the built-in print command, we use draw_string and show_screen commands to display output. The plus here is that we can have text in color. The show_screen is displayed until either the [ EXE ] or the back buttons is pressed.
The input command returns us to the Shell and is not part of the Casioplot commands.
Source for the Formulas Used:
Inch Calculator “Engine Horsepower Calculator”. Calc Hub, LLC. 2025. https://www.inchcalculator.com/engine-horsepower-calculator/ Retrieved May 5, 2025.
Eddie
All original content copyright, © 2011-2025. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
