Expt-2 : Interfacing 7-segment Display Device and Practicing Digital IO Commands

(1) The Experiments of the attached file were carried out by as many as 6 Sections of undergraduate students; each section containing about 25 pupils against their Lab Course, EEE-3210. The Lab Works are immediately followed after the related Theory Course, EEE-3209. This is the same Teacher who takes both the Theory and Lab Classes. There are co-teachers in the Lab as helping hands.

(2) Every student had his own repackaged version of Arduino UNO Learning Kit (pictured below) and the Laptop/Lab PC. The outcomes of the students were remarkable. It was mainly due to repetitive practice in making/breaking wiring for different kinds of interfacing circuits, writing programs on paper, showing the programs to the Lab Teachers, and then uploading the programs (sketches) in the Kit.

(3) We are posting our experiences here in the Arduino Forum as our works are related with Arduino UNO; it may be useful for some other people in some other places for good reasons!

A partial snapshot of the Lab Class on ATmega32 Microcontroller Interfacing and System Design using Arduino UNO Learning Kit of 3/2 students of the Department of Electrical and Electronic Engineering,
Ahsanullah University of Science and Technology, Dhaka, Bangladesh.

Experiment2 (1).pdf (566 KB)

No current limit resistors tho?
How bright are the displays when the code is running? Guess it depends on multiplexing speed with more than 1 digit.

@CrossRoads

I had a long discussion with AWOL on this issue (and once with you) of 'not placing the current-limiting' resistors. I am giving the links of those posts below. I did not stand in favor of 'no need attitude'.

We have avoided the use of these resistors (we need 8 discrete resistors; network type resistors are not easily available here) to save breadboard space.

Our experiments were of short duration, demonstrative type. In real field applications, one must use current limiting resistors (560R - 1000R) to ensure that the MCU ports and 7-segment devices are not prematurely destroyed due to over stress.

Thanks for reminding me this important equipment safety issue.

Current Limiting Resister(1)
Currnet Limiting Resistor(2)
Current Limiting Resistor(3)
Current Limiting Resistor(4)