Developement board design suggestions

[MrDEB]

Been a big fan of Swordfish so much so that I myself am in the process of designing a PIC development system consisting of 2 -3 boards depending on size of chip desired.
Board 1 to hold a 40 pin socket this is the main basic board
Board 2 to hold a 28pin socket this is a daughter board for board 1
Board 3 holds an 18 pin socket this is a daughter board for board 1 or 2
Board 1 has an - LCD 4bit port,
3 LEDS that can be configured to indicate HIGH or LOW
two ADC headers (contemplating having resistor ladders on board?)
one ICSP port that serves three different functions – Programming, Uart, Logic probe
one I2C / SPI port
Daughter boards to have option of adding tactile buttons
Have some room on Board 1 and contemplating a PCboard that breaks away from board to solder LCD to then just use a 10 pin M/F plug and ribbon cable to connect the LCD to Board 1.
Most if not all the options on Board 1 to be available on daughter board inserted into Board 1
At present looking for suggestions of additional features but keeping cost as low as feasible.

[brad]

Well, I like using LED's a lot so I would recommend putting in an LED matrix of some sort and perhaps some seven segment displays?

Also maybe some sort of keyboard / keypad would be handy.

[MrDEB]

Problem with LED matrix is they mostly have different pin outs unless I go with say a KINGBRIGHT bi colored with a part number to purchase (I am looking at just selling the boards but ?
As for a keyboard, will research for economical piece. Bear in mind I want to keep the finished product as inexpensive as possible but the hobbyist doesn't need to put all the bells n whistle on at first.

[brad]

You say you are looking to sell them, do you mean as a kit for people to build or will you make them and then sell them?

I don't quite see the problem with the LED matrix though, even if they have different part numbers - couldn't you just chose one particular part number and then make sure you just use that one?

I should have explained better with the keypad - I meant you could have a simple little board that has a grid of maybe 4x4 buttons on there that would certainly come in handy for different projects to be built on this kit

[MrDEB]

Looking at different options for sale
Either just bare boards or as a kit with most popular options.
Even looking at having two boards or 3 all the same size but using a V-grove to break away an option board (example, have the 40 pin board with a breakaway section to use as LCD pcboard. Solder the 16 pins to board then have a 2 x 5 header plug so a ribbon cable can be used to connect the LCD)
Do the same for a keyboard and led matrix.

[MrDEB]

Found a 12 key keypad at Sparkfun for $3.95
Board is progressing and will post board layout pics as soon as I get them done.
Still need to add the led Matrix, looking at bi-color.

[brad]

Will you be making the matrix easier to interface by adding something like 74595 chips?

[MrDEB]

Contemplated including a place to use a "driver" such as 74595 but I like the TLC5917. Only one resistor needed verses 8. This is a "sink" instead of "drive"
Upgraded to Diptrace lite so I can confirm related pin outs between Boards.
Need to research Diptrace for adding a grove to allow a break away section.

[brad]

I think what you might be looking to do is just place a whole big line of holes down the length of the board, in DIPTRACE, this picture shows what button to press to get holes

screen-capture-22.png (5.5 KiB) Viewed 24277 times

[MrDEB]

Elcrow on their site mentions a grove for doing panelizing but the holes seem simpler. Couldn't remember what the name of the other(SNEED or ITEAD Studios). Have had some boards done by them but saw some negeative comments about them ?

[MrDEB]

In process of researching how to program an Arduino so I cam across the FT232RL device but is there a better way to program. Was looking for a method to use the ICSP header but looks like its been tried but fails

[brad]

I used that sort of circuit in my PICnDuino

Perhaps you could have a look at Bitfogavs board, it might help you on your way.

Otherwise, if you wanted to go Arduino at all, the leonardo version doesn't need any sort of usb to serial conversion, it does it all in the one microcontroller

[MrDEB]

The Adrunio board is in addition to the basic development board's. The Adrunio is a daughter board that plugs into my Board 1 w/ a 40 pin socket etc. then the Adrunio can access all the options on boards 1, 2, and 3. I want to keep it as simple as possible but it's getting out of hand with an LCD, 8 x 8 matrix and keyboard options.
Will research this leonardo micro?

[MrDEB]

It looks like the USB to serial board that Sparkfun has for $14.95 is my best choice All I need to do is have a section to solder two 9 pin headers then let the hobbiest purchase the usb / serial board.

[MrDEB]

Been rethinking the daughter board arrangement and contemplating using edge card connectors instead of headers. Would allow more room on main board w/ all the options thus a lower cost.
What is your feeling on edge card verses headers. It was mentioned several years ago that edge card is old school but they are still used so can't be all that bad.