Data Logging Shield Question

[Donziboy2]

Doing some research to build a school funded project and im looking to get a MEGA and a logging shield. I would use an Uno but I need more pins then the Uno has. What has to be done hardware wise to make the Adafruit data logger work with a MEGA board?

Im going to attempt to run 13 7seg displays using 595's, a 128x68 lcd, a data logger, a membrane keypad, and a few sensors. <Uno falls short on pins
Im not even sure if all this can be connected to a board and still function at the same time.... Ideas?

[adafruit_support_bill]

That's a lot of stuff for one processor. Have you considered splitting the functionality between two boards? Maybe data acquisition & logging on one and your UI devices on the other. Communication could be via serial or I2C.

I believe that the primary difficulty now with running the logger on the MEGA is with the RTC. The MEGA uses different pins for I2C.

[Donziboy2]

Is it possible to share the Logger with 2 Uno boards?
The logging portion would be something that happens daily at night, it would be a small log (date and a sensor count number up to 9999). Im actually considering some form of EEPROM, but the logger makes it easy since it has the RTC and storage all in one.

Here is a basic mockup of what I was looking to make.
If its easier to run two small microprocessors then one mega I might just go with a pair of Ardweeny's, It depends on how things work out.
It will display time, temp and will have a counter for number of entry's per day, for the school library. And will log the daily entry count at night so that they will have some data on what days are busiest and such.

Right now its all in planning stage, id like to reduce the cost anywhere possible. The mega ($32), logger($19.50), and 128x64 lcd($24) make up 3/5 of the price atm. I also need to find a decent entry sensor, been looking at garage door safety beam sensors but they are $20-30. Cheaper the total cost is the easier it is to get the build approved.

All thoughts/ideas welcome

[Donziboy2]

Im thinking I can get away with just an UNO or a nano, im going to make an RTC/EEPROM board to go with the uno/nano I use. My main issue atm is weather or not the LCD and 7 Seg's will be able to share the SPI pins. Im not looking for blazing speeds, the LCD will be Menu mainly and maybe run thru some simple animations(5 FPS at most) when not being used as a menu. The clock/temp/counter dont need to be quick refresh rates either, they just have to all work togeather and not cause issues.

If they cant I will have to use a pair of micro's and that will add more work to get them to play nice with each other and share the RTC/EEPROM.

[adafruit_support_bill]

Here is a logger sketch that works with the mega:
http://forums.adafruit.com/viewtopic.php?f=31&t=27245
Thanks Fat16Lib!

[Donziboy2]

Nice!
I think im going to change from 595's to 7219's. I will only need 2 to run all the 7 segments displays.

[Donziboy2]

Ok another update and just finished more reading
I was going to use a KS0108 LCD but discovered it uses alot of pins and may have issues sharing the SPI pins.
So im going to go with the ST7565 LCD http://www.adafruit.com/products/250

So I have 2x Max7219 on D10, D11, D12 , Running 13+ 7 segment displays
D5, D6, D7, D8, D9 on ST7565 LCD (128*64).
A4, A5 on RTC/EEPROM

This leaves me a few D/A lines for buttons and sensors.

Still not sure if there is enough mem/flash on a 328, ill use a breadboard arduino to see how it works out, its probably gona be 2-3 weeks before i get parts in to start this since i have other projects.