Seven Segment Display

Purpose Of This Page 
 This page explains how to show numbers on the CodyNick Seven Segment Display using Python. 
 The Seven Segment Display is useful for showing: 
 
 Scores. 
 Counts. 
 Sensor values. 
 Timer values. 
 Simple numeric feedback. 
 
 By the end of this page, students will be able to: 
 
 Display a positive number. 
 Display a negative number. 
 Display a decimal number. 
 Update the displayed value inside a Python program. 
 
 
 
Figure 1 - CodyNick Seven Segment Display for showing numeric values.
 
 Start Code 
 Every CodyNick Python script should import the CodyNick library and connect to the CodyNick device. 
 import CodyNick

cn = CodyNick.CN()
 
 The variable cn represents the connected CodyNick device. 
 Display A Number 
 Use Seven_Segment.display() to show a number. 
 Function format: 
 CodyNick.Seven_Segment.display(cn, value)
 
 Example: 
 import CodyNick

cn = CodyNick.CN()

CodyNick.Seven_Segment.display(cn, 1234)
 
 This displays 1234 . 
 Display A Negative Number 
 The display can show negative values. 
 Example: 
 import CodyNick

cn = CodyNick.CN()

CodyNick.Seven_Segment.display(cn, -123)
 
 This displays -123 . 
 Display A Decimal Number 
 The display can also show decimal values. 
 Example: 
 import CodyNick

cn = CodyNick.CN()

CodyNick.Seven_Segment.display(cn, 1.234)
 
 This displays 1.234 if the value fits on the display. 
 Using Strings Or Numbers 
 The value can be passed as a number: 
 CodyNick.Seven_Segment.display(cn, 1234)
 
 It can also be passed as a string: 
 CodyNick.Seven_Segment.display(cn, "1234")
 
 Both examples display the same value. 
 Display Range 
 The display is designed for short numeric values. 
 Typical useful values are: 
 
 
 
 Type 
 Example 
 
 
 
 
 Positive integer 
 1234 
 
 
 Negative integer 
 -123 
 
 
 Decimal number 
 1.234 
 
 
 Small decimal 
 -1.23 
 
 
 
 Very large or very small values may not fit on the display. 
 In the CodyNick Python library, values outside the normal display range are treated as out of range. 
 Example: Count Up 
 This example counts from 0 to 9 . 
 import CodyNick
import time

cn = CodyNick.CN()

for number in range(10):
 CodyNick.Seven_Segment.display(cn, number)
 time.sleep(0.5)
 
 The number changes every half second. 
 Example: Countdown 
 This example counts down from 5 to 0 . 
 import CodyNick
import time

cn = CodyNick.CN()

for number in range(5, -1, -1):
 CodyNick.Seven_Segment.display(cn, number)
 time.sleep(1)
 
 The third value in range(5, -1, -1) means the loop counts down by 1 . 
 Example: Show Decimal Values 
 This example displays a few decimal values. 
 import CodyNick
import time

cn = CodyNick.CN()

values = [1.234, 2.5, 3.75, -1.23]

for value in values:
 CodyNick.Seven_Segment.display(cn, value)
 time.sleep(1)
 
 Function Summary 
 
 
 
 Function 
 Purpose 
 Example 
 
 
 
 
 Seven_Segment.display(cn, value) 
 Display a number 
 display(cn, 1234) 
 
 
 
 Practice Tasks 
 Try these exercises: 
 
 Display 1234 . 
 Display -123 . 
 Display 1.234 . 
 Count from 0 to 9 . 
 Count down from 9 to 0 . 
 Display a list of decimal values. 
 Create a timer that counts seconds. 
 
 Common Mistakes 
 The first argument must be the connected CodyNick device: 
 CodyNick.Seven_Segment.display(cn, 1234)
 
 This is not correct: 
 CodyNick.Seven_Segment.display(1234)
 
 If a value is too long, it may not appear as expected on the display. 
 Use short numeric values: 
 CodyNick.Seven_Segment.display(cn, 1234)
 
 When using a loop, add a delay so each value can be seen: 
 time.sleep(0.5)
 
 
 Page summary: 
The Seven Segment Display shows short numeric values. Use `Seven_Segment.display(cn, value)` to display integers, negative numbers, or decimal numbers from Python.