Binary Counter — Logic Analyzer

Build an LED Binary Counter & Improve The Code — ArduSeries #88

Published in

Jungletronics

3 min readDec 20, 2019

Hi, Let’s make an 8-bit counter with Arduino and use it to study this Logic Analyzer 24 Mhz8CH:)

Fig 1. An 8 channels Logic Analyzer from China :/ How it works?

To see how it works let’s bring some codes for discussion: Counters!

[TODO: COUNTING GIFS CIRCUIT WORKING GOES HERE]

Let’s initialize with some of the easiest counter codes there is to learn, then put some science and experience on it, for finally, use that cheap Logic Analyzer (24 MHz 8 Channels) and see how it works:)

Fig 2. First, prepare your Breadboard for all this lab: 8x LEDs, 8 x 220 Ohms Resistors, Arduino and jumpers:)

After building a breadboard, here is the first program (please see this video from Paul McWhorter):

The purpose is to test the hardware (There are any LEDs burned?)

The First Code — Testing The Hardware

Fig 4. The purpose of this code is to test the hardware; all 4 LEDs will be turned on

As you know there are many approaches to coding the 4-bit counter in Arduino; here I present what is probably the most obvious code ever. Let’s make the real 4-bit counter (brute force approach):

The Second Code — 4-bit Counter

Fig 5. This code counts from zero until 15 (4-bit counter); it consumes 1528 bytes (4% of program storage space) and Global variables use 9 bytes (0%) of dynamic memory:)

Let’s make some improvements on the previous code; the magic number turns out to be variable for easy maintenance:)

The Third Code — 4-bit Counter Improved

Fig 6. This is improved by writing the number to the variable: maintenance is much easier:) it consumes 1660 bytes (5% of program storage space) and Global variables use 9 bytes (0%) of dynamic memory:)

The brute force approach is not applicable for counters greater than 4 bits; for 8-bit we will need to have 255 blocks to cope with all LED’s states :/

Now let’s make some real code:

The Forth Code —Sophisticated 4-bit Counter

Fig 7. This code is extensible; it consumes just 976 bytes (3% of program storage space) and Global variables use 18 bytes (1%) of dynamic memory:)

If you want to understand the code above, please consider watching this video:

HEX_BITS_DEC_TABLE

Sheet1 Hexadecimal,8 bits,Decimal 7,6,5,4,3,2,1,0 00,0,0,0,0,0,0,0,0,0 01,0,0,0,0,0,0,0,1,1 02,0,0,0,0,0,0,1,0,2…

docs.google.com

Now the last code is for the 8-bit counter:)

The Fifth Code — Sophisticated 8-bit Counter

Fig 8. This code is extensible; it consumes just 982 bytes (3% of program storage space) and Global variables use 26 bytes (1%) of dynamic memory:)

Now let’s read at least 4 channels with Logic Analyzer (24 MHz 8 Channels).

Run the second code (_88_logicCounter_PaulMcWhorter_4bits_02.ino) and see this graph running Saleae Logic Analyzer Software.

Fig 9. 4-bit Binary Counter displayed in 4 channels; the initial duty is .5s, and the next is .5s/2 and so forth…

Now run the last code — 8-bit counter () and you should see 8 channels, but unfortunately, I did not make my Chinese & cheap clone Logic Analyzer 24 Mhz8CH work for all channels: only 6 worked (and I do not discover why…may you help me?)