The Electronics Hobbyist » supplies

Workbench Challenge Update

Natalia — Tue, 27 Dec 2011 22:22:35 +0000

Back in April I posted about a goal I had for this year: setting up a decent workbench for myself in a corner of my (minuscule) home office. As the year comes to an end, I think it’s time for an update.

Did it happen exactly as planned? No…

Did I make progress? Yes!

So what happened?

We’re in limbo right now. We live in a rented apartment, which the owner has put on the market for sale. That means at any given day we may get a 30-day notice to vacate. I simply didn’t feel it was worth it to go all the way with getting rid of stuff to make room for a bigger table (it will inevitably happen when we have to move) and buying the table/bench (that would have to fit the exact dimensions of the space available here, possibly not being the ideal size for the next place) just yet.

I did make some improvements: I doubled my work area (with an additional table – another dinner tray table! – I use when I’m working on something) and I added a few items to my set of equipment. I got a digital multimeter (my old one is analog, which I still keep as I read it can be useful to show changes in values) a bench-top power supply, hot glue gun, several large breadboards, much needed tools and a myriad of parts.

All in all I don’t have the workbench I had envisioned (yet), but I have a bigger workspace, much needed new equipment and a lot more parts to play with!

On a related note, I came up with ideas for two bigger projects I want to work on which will be ongoing, in addition to the small stuff I build for learning purposes. I’ve placed quite a few orders from DigiKey, Jameco clearance center and CuteDigi lately, that I’m sure my husband now fears I have a shopping addiction… I am excited to start working on these projects and sharing them here. Stay tuned!

My current setup:

The work area:

And storage:

How about you? What is your workbench setup like? Are you planning any improvements and/or additions in 2012?

Controlling a Seven-Segment Display Using Arduino Part 2

Natalia — Mon, 08 Feb 2010 15:00:00 +0000

This month’s project is a simple program to display the Arabic numbers using the Arduino and a 7-segment display.

Parts list:

Arduino Duemilanove
7-Segment Display(I got the grab bag, with 50 displaysfor $10.95)
Breadboard
Mini Push Button Switch
Jumper Wire

The 7-segment display used in this example is a common anode display with pin connections as shown in the picture, and the Arduino sketches were written so as to light up a segment when the corresponding pin is LOW.

The first of a series of three simple sketches cycles through the numbers from 0 to 9, resets the display to show a “0″ once it reaches “9″ and repeats until the power is turned off on the Arduino. The code below accomplishes this in a very simplified manner, as each digit is formed by a separate function that sequentially lights up each of the necessary segments to display that number.

The third sketch in this sequence will use individual bits to represent each segment and will require less written code, a good thing to keep in mind when programming microcontrollers, as they have a small memory footprint (the Arduino Duemilanove has 32K bytes of program memory).

Sketch #1:

// www.TheElectronicsHobbyist.com/blog
// Natalia Fargasch Norman
// Seven-segment LED Display
// Common Anode pins 3 and 8

//   G F + A B
//   | | | | |   -> pins and segments they control
//   ---------
//  F|   A   |B
//   |---G---|   -> segments
//  E|   D   |C
//   ---------
//   | | | | |   -> pins and segments they control
//   E D + C DP

// Segments that make each number when lit:
// 0 => ABCDEF
// 1 => BC
// 2 => ABDEG
// 3 => ABCDG
// 4 => BCFG
// 5 => ACDFG
// 6 => ACDEFG
// 7 => ABC
// 8 => ABCDEFG
// 9 => ABCDFG

// Arduino digital pins used to light up
// corresponding segments on the LED display
#define A 2
#define B 3
#define C 4
#define D 5
#define E 6
#define F 7
#define G 8

// Common anode;
// on when pin is low
// and off when pin is high
#define ON LOW
#define OFF HIGH

int ms = 1000;

void setup() {
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(F, OUTPUT);
  pinMode(G, OUTPUT);
}

void loop() {
  zero();
  one();
  two();
  three();
  four();
  five();
  six();
  seven();
  eight();
  nine();
}

// 0 => ABCDEF
void zero() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, ON);
  digitalWrite(F, ON);
  digitalWrite(G, OFF);
  delay(ms);
}

// 1 => BC
void one() {
  digitalWrite(A, OFF);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, OFF);
  digitalWrite(E, OFF);
  digitalWrite(F, OFF);
  digitalWrite(G, OFF);
  delay(ms);
}

// 2 => ABDEG
void two() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, OFF);
  digitalWrite(D, ON);
  digitalWrite(E, ON);
  digitalWrite(F, OFF);
  digitalWrite(G, ON);
  delay(ms);
}

// 3 => ABCDG
void three() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, OFF);
  digitalWrite(F, OFF);
  digitalWrite(G, ON);
  delay(ms);
}

// 4 => BCFG
void four() {
  digitalWrite(A, OFF);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, OFF);
  digitalWrite(E, OFF);
  digitalWrite(F, ON);
  digitalWrite(G, ON);
  delay(ms);
}

// 5 => ACDFG
void five() {
  digitalWrite(A, ON);
  digitalWrite(B, OFF);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, OFF);
  digitalWrite(F, ON);
  digitalWrite(G, ON);
  delay(ms);
}

// 6 => ACDEFG
void six() {
  digitalWrite(A, ON);
  digitalWrite(B, OFF);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, ON);
  digitalWrite(F, ON);
  digitalWrite(G, ON);
  delay(ms);
}

// 7 => ABC
void seven() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, OFF);
  digitalWrite(E, OFF);
  digitalWrite(F, OFF);
  digitalWrite(G, OFF);
  delay(ms);
}

// 8 => ABCDEFG
void eight() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, ON);
  digitalWrite(F, ON);
  digitalWrite(G, ON);
  delay(ms);
}

// 9 => ABCDFG
void nine() {
  digitalWrite(A, ON);
  digitalWrite(B, ON);
  digitalWrite(C, ON);
  digitalWrite(D, ON);
  digitalWrite(E, OFF);
  digitalWrite(F, ON);
  digitalWrite(G, ON);
  delay(ms);
}

Starting Out on an Electronics Hobby – Resources

Natalia — Sat, 21 Nov 2009 03:13:00 +0000

Surround yourself with all things electronics:

Books: hobby electronics books on Amazon.com

Magazines:

Read up on electronics online:

Find good sources of electronics parts and components:

There are plenty of reliable electronics supplies stores online such as Parts Express, Jameco Electronics and CuteDigi. Also check out local junk yards and flea markets, and last but not the least, ebay.