Say, a group of college students were interested in assembling a home-brew proto-ATM (for kicks, and as Bsc thesis). What would your advice be concerning main 'cpu' microcontroller, tool-chain (C or low-level), other spare parts (real and makeshift)?

Mainly, I'd like to know, wich atmel(pic?) micro can be easily interfaced with a (computer)vga monitor, and would have enough ram (etc) to carry the back-bone burden?

What would be the best(more painless) way to interface the atm with back-end 'bank' server(puter with user accounts db) - usb, com, maybe vired UDP-networking?

I have not discussed with the group in question their point of view of the problem domain yet, and i hope to get some feedback here, to correlate both your info(and i know there are a lot of seasoned gurus here) and their ideas.

The general moto is to get away with something resembling bare-bone atm, minus security (well, perhaps some primitive tamper-controll).

Personnaly i find the idea very stimulating, and i hope you are too!

Thanks, waiting your comments :)


Posted on 2011-04-14 10:05:58 by Turnip
You'll need ARM-based MCUs and ethernet. I'd look at chips used in routers, that have full documentation and devkits and linux kernels. :)
Posted on 2011-04-24 04:20:50 by Ultrano
I don't personally like ARM, however, I'd have to agree. Theoretically, you could use an Atmel AT90Uxxx series 8-bit uC w/ the AVR Ethernet Adapter for networking and just throw a USB external graphics card on there for video output. However, you'd have to code both a protocol stack and the firmware for the external display. That being said, once setup you're probably going to run out of pin's somewhere along the line and space will definitely be an issue (trying to support both a bare-bones protocol stack and video drivers might be a bit much for the low-end MCU).

If it was my project (say I was designing a toy router) I'd probably stay away from ARM and base my board around one of the PIC32MX360 chips and a starter board. I've not checked into prices of ARM but you can get a decent PIC32MX360 chip for like 5 or 6 bucks and prototyping boards for around 70/usd. Not quite as cheap as the Atmel boards, but you'll definitely get what you pay for.

Btw (and I know I'll be flamed for this but....) if you're planning on ever doing an release boards, stay away from Atmel, use Microchip. I use AVR cause I just do hobby projects and they are REALLY quick and easy to get up and running fast. However, unlike Microchip's PIC's which have been around FOREVER, AVR's are fairly new and still more or less beta-ware.

please don't start an argument with me about the Atmel's execution speed vs the PIC I'm aware of that but stability and speed don't always go hand in hand and when it comes down to it, I'd trust a PIC on something safety critical long before I would ever think of using an AVR. (just opinion I suppose)
Posted on 2011-04-24 21:11:39 by Synfire