This project can be used to help students learn the binary number system and the process of counting in binary. The circuit counts up from 0 to 15, displaying the binary count using four LEDs, and displaying the corresponding decimal value on a number+ bit. It then resets the number displayed to 0 and continues the counting process over-and-over until power is removed from the circuit. The rate of counting can be controlled by a pulse bit.

For more advanced computer science students, a study of the circuit is quite constructive. The circuit makes use of four cascaded latch bits and several inverter bits. Resetting the count back to zero is accomplished by the use of a threshold bit that outputs to the reset input of the number+ bit. To see the circuit in action, click on the mp4 video included with this project. For details on bits used follow this link: http://littlebits.cc/projects/binary-number-system-trainer-up-counter

**Duration: 1 45-minute class**

**GRADE LEVEL**

High School (ages 14-17)

Middle School (ages 11-13)

**DIFFICULTY**

Intermediate

Advanced

**SUBJECT**

Engineering

Computer Science

Math

**MODULES & ACCESSORIES USED (30)**

usb power (1)

led (4)

pulse (1)

fork (1)

inverter (6)

latch (4)

split (3)

mounting boards (6)

E – USB Power Adapter + Cable (1)

threshold (1)

number (1)

wire (1)

**LESSON GUIDE**

**STEP 1 : Set the Threshold Bit**

If you are constructing a 4 bit binary counter as shown in the main image, then set the threshold bit to the value 16. You can learn how to set the threshold bit by going to this Web address (it is easy to do!): http://littlebits.cc/bits/threshold

**STEP 2 : Construct the Circuit**

Construct the circuit shown in the attached UpCounterCircuit.pdf file. For details on the bits used, follow this link: http://littlebits.cc/projects/binary-number-system-trainer-up-counter.

**STEP 3 : Add Number Place Values to the LEDs**

Use double stick tape to add the numbers 1, 2, 4, and 8 to the LEDs.