My granddaughter enjoys playing Bingo, so I went out and bought her a
cheap set at a local discount store. The cards and the markers are fine,
but the spinner disk for selecting the numbers is a piece of garbage.
It flew apart about ten minutes into the first game.
True, I could have gotten a more expensive Bingo game, say for $10 or
so, one that uses a clever little hand-cranked cage and teensy wooden
decaled balls to select the numbers. But, hey, all of us Instructables
people are DIY-ers, so I decided to build a number generator using an
ATMega 328 CPU and a garden-variety 16x2 LCD display. I would test and
debug the code on my Arduino Duemillanove with LCD shield, and then build
the handy-dandy Bingo Number Generator as a stand-alone project on a
prototyping board. This means that you need not build the hardware for
this project -- you can run the code on an Arduino with LCD shield and
get the same functionality. But, why tie up your development board every
time you want to play Bingo? And why cheat yourself of the fun of
Essentially, we'll be constructing a stand-alone Arduino, with a built-in
LCD socket and hard-wired momentary-contact switch. It will lack only
the female header strips for plugging in shields, though you could
optionally add those, too. Consider this project as a sort of prototype
all-purpose microcontroller board with display. So, even if you're not
a Bingo enthusiast, this should still be of interest.
Step 1: What You'll Need
This project does require a fair amount of hardware,
but none of the components listed below are difficult
to find or particularly expensive.
ATMega 328 CPU 6.00
16x2 LCD display 4.00
[Radio Shack 276-168, or similar]
LM7805 5v regulator .50
1N4001 diode .25
resettable polyfuse .35 [optional, but recommended]
[All Electronics, catalog # RXE-065, or equivalent]
40-pin male header strip .75
40-pin female header strip .75
28-pin IC socket, narrow .75
mini pushbutton switch .50
momentary contact switch .50 [generic]
16-MHz crystal 1.00
mini 10K trimpot .25
330-ohm resistor, 1/4 watt (2x) .50 [anything from 220 to 1k is okay]
LEDs (2x) .35 [generic, one red, one green]
power jack, coaxial [2.1 mm] .75 *
power plug, coaxial, [2.1 mm] .75 *
[Radio Shack 274-1569, Size M, or similar]
100 uF capacitors, 25-35v (2x) 1.00 [Don't get the 16v kind.] **
10 uF capacitor [optional] .50 [for extra filtering]
22 pF capacitors (2x) .50
.1 uF capacitors (2x) .50
* Make sure you get a matching set of plug and jack.
There are several similar-looking ones in approximately
the same size, and they are NOT necessarily cross-compatible.
[I could go on a rant about lack of standardization in plugs and jacks,
but this is not the appropriate time or place.]
** If you use a filter cap with at least a 25-volt rating, then you can
plug in a 12-volt power supply with no worries. A 16-volt filter cap
may not give you enough tolerance.
Hopefully, you have at least a few of these components in your spare
parts box. If you had to buy each and every one of them, the total could
easily run over $20.