Looking to make Arduino more computer like for future project

I'm looking to breadboard new parts to an Arduino.

First, let me please tell you what I'm doing.

I'm trying to make the Arduino more computer like. I'm going to connect a standard HD44780 LCD. I wish to add a PS/2 Keyboard to Breadboard adapter, an RCA to Breadboard adapter or possibly an MP3 shield.

I'm looking for alternate sources for the PS/2 Keyboard to Breadboard adapter, RCA to Breadboard adapter, etc.

Having never done this before, I'm also wondering what my selection of pins should be when I go to make a shield.

If I have any pins left, I might want to add a joystick:

http://www.sparkfun.com/products/9032 http://www.sparkfun.com/products/9760

LCD: http://www.adafruit.com/products/198

Other parts:

http://www.mouser.com/Search/ProductDetail.aspx?R=28060virtualkey61900000virtualkey619-28060

http://www.mouser.com/Search/ProductDetail.aspx?R=28050virtualkey61900000virtualkey619-28050

Hi,

I'm not completely sure what you want to build... Shield usually is a piece of PCB fitting the connectors of the arduino.

Since you talk about breadboard connectors, do you want to buy a perfboard shield and solder the "breadboard"-components on it ? Or would you like to use them on a breadboard and connect the arduino by wires ? both (since a breadboard shield exists) ? Or do you want to design your own PCB/shield using these adapters ?

Which pins you should use depends a little on what you want to do. In theory you could use the pins you like. Some pins have special functions and some peripheral chips/circuit may also need special pins.

I wouldn't use pins of the serial port fast for example, since they're used to talk to the PC. But in a stand-alone project I might.

When it comes to pins it's also a matter of what the components of your project will require. Should the MP3-shield for example need a fast SPI-port to work properly, then it may... be possible to use software SPI and just choose any pin, but connecting the shield to the right pins of arduinos hardware SPI-port will probably give much better results.

Luckily the joystick shield uses just buttons which can be read digitally by any pin, should you have chosen one using pot-meters, you would... have to connect them to to pins capable of reading analog values.

I know it's possible but haven't worked with PS2-keyboard on my arduino yet, I also don't know what you would like to do with the RCA-plug. Check... whether the keyboard and other purposes are possible with just any arduino pins or that they require special ones.

It's also good to think what you would like to do your project and whether it should be expandable. Reading joystick buttons using pins that also can be used for I2C-applications is possible. It may pose a problem when you would like to add an Real time clock-chip that uses I2C later on for example.

Having enough pins...

You probably need a lot of IO-pins for the items of your projects, but you don't need every item to be connected directly to the arduino. A port-expander chip like the PCF8574 is controlled by I2C, uses 2 pins of the arduino and gives you 8 IO-pins in return. Two of these chips, connected to the same I2C-bus/Arduino pins, would already be more then enough to drive LCD and probably read 2 joysticks. If you wanted... you could connect up to 16 (x8 pins) of these chips at the cost of 2 arduino-pins.

Shift-registers require another technique of addressing, also use just a few pins of the arduino, and are usable to create hundreds, perhaps thousands, io-pins.

Creating pins these ways to free arduino pins is possible but some parts of your project may need to be connected to the pins of the arduino directly. In order not to miss keystrokes connecting the keyboard to arduino directly is probably best. An MP3-shield may also require to be connected directly.

Simpson_Jr: I'm not completely sure what you want to build...When it comes to pins it's also a matter of what the components of your project will require.

I have programming experience and I can solder pretty well on through hole components. I don't have a lot of electronical experience but I'm reading and trying to learn all that I can. I have surveyed a lot of components and projects and I have a couple of online friends willing to answer questions.

I thought I would start with Arduino because the number of tutorials will make it easy to learn but I want to upgrade to a Maple Leaf because it is Arduino compatible, has more RAM for computer programs and has more CPU power making it a better choice for my project because the processor in the Maple Leaf is more computer like.

I'm trying to make a computer with microcontrollers which means that I need a keyboard, a display, sound, an SD card for a file system, etc. If I can get there, I'll be pleased. If I don't then I at least tried. I want to at least get something that is semi-functional with the keyboard and the display and I'll try to move on from there.

I would ultimately like to move on to a VGA display.

I am looking for alternate components in the way of keyboard to breadboard, vga to breadboard, sound chips, video chips, etc.

Thank you for answering me. I'll try to answer you some more real soon.

I would ultimately like to move on to a VGA display.

Not with an Arduino, you won’t. I think you should start with something that has the power and speed that you will need. An Arduino isn’t it.

It is possible, if you use a micro-controller to do each task, and have a master one coordinate everything, the VGA can be done using an ChipKit32 or a Mapple or even an FPGA.

KE7GKP:
Using an Arduino to create a system capable of keyboard, display, sound and file-system is extraordinarily aggressive as a first project. Suggest scaling your plans back to something more realistic as a first project.

I would probably start with an LCD and keyboard and go from there. I think the SD card would be the most challenging and need the most memory for a file system.

As far as speed needs are, I would upgrade to a Maple Leaf if I got that far because it has more speed.

As long as the board has the pins, I don’t see why I can’t use all of the pins as long as there is memory. I think even the Netduino might have a little more memory over a regular Aduino.

Chuckz:
I would ultimately like to move on to a VGA display.

Check this out:

http://www.strichlabs.com/products/vga-shield

I saw that while I was purchasing another of their products. I had some trouble and they told me they are transitioning from one web site to another. I expect they will have everything posted. They make their schematics and such available.

But yes, its like adding a pickup to a skateboard, but if you want to make an Arduino drive a VGA monitor, I guess this will do it.