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.

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:

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

Practice Tasks

Try these exercises:

1. Display 1234.
2. Display -123.
3. Display 1.234.
4. Count from 0 to 9.
5. Count down from 9 to 0.
6. Display a list of decimal values.
7. 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)