# Can you suggest a solution?

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#### RobertRoss

##### Member
Hello,

I want to design an electronic board with a microcontroller which can communicate with some external flash memory (approximately 16 mbytes to hold some graphics). The microcontroller has to be able to communicate with a color 1.5" tft LCD which can display at minimum a collor depth of 16 bits/pixel.

I should be able to design my own controls. For example, I would like to design a drop down list box with unique features in terms of graphics. Special backgrounds are shown when the drop down is down with special text fonts as the items in the list and so forth. The system should also comprise touch screen capabilitites. Also I should have a way to store atleast 4 sizes of a particular font. I also should be able to download into the flash memory pictures, icons and patterns and be able to execute their display with some C function that would reside in the microcontroller. Also, the display should be able to do wallpaper and watermark. The objective of this is to have a miniature microcomputer system which would allow me to develop any application in C inside the microcontroller.

Here are my questions:

1) What is the best microcontroller to use for this?

2) Should I use Linux, WCE or a proprietary kernel that I will design from scratch?

3) What would be the approximate costs if the Linux/WCE option would be considered?

4) The above has to fit in a PC board of a maximum size of 1.5" x 1.5" !

5) Can the above system be built using parts that would not total to more than 8$(TFT LCD excluded) ? 6) Approximately, how long would it take for an engineer to develop the above specifications if I were to subcontact this to a company? Sincerely yours Rob Last edited: #### Sceadwian ##### Banned You won't find Linux or Windows CE for micro controllers that's for sure, and there's no way you're gonna build it for under 8 dollars. You need to outline your specifications a whole lot more than you already have if you expect a responce. Knowing what the TFT module is would help for starters. #### RobertRoss ##### Member Thanks for replying! Hello Sceadwian, Okay fair enough.... I thankyou for your response! Here is the LCD part number... its an Optrex part. T-51991GD015-MLW-AIN >You won't find Linux or Windows CE for micro controllers that's for sure But I have seen Atmel coming out with microcontrollers that load Linux with volume pricing of 8$ each? Or even better see link below:

http://www.linuxdevices.com/news/NS8107946385.html

>You need to outline your specifications a whole lot more than you already have if you >expect a responce

Okay, basically, we have a controller that can talk to a color LCD and based on how I program the controller (using C language) we are able to display pics, icons or text on the LCD. For exampe, suppose I press on a button connected to my controller, and my code sees the button, well then the logic goes and fecth a picture stored in flash and displays it on the lcd. *or* say I press the same button and a listbox comes out on the lcd instead.

Obviously, prior to any programmation, there has to be a way to store all these pictures, icons and texts in the flash memory, and then use a specific set of functions that reside in the microcontroller that carry out the display operations based on the paramenters you pass into these functions.

Could we do this using Linux or CE ? Or is it better to design my own miniature kernel/OS?

Yous feedback is much appreciated!

sincere regards
Rob

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##### Banned
I've always liked Optrex modules, they have very simple interfaces and seem like really nice units. You could probably use a standard micro controller as the display driver but it'd be very basic. To run an entire OS like you're talking about would require signficant skill in designing routing and building small PCB's, not easy and I'd say a bit out of the realm of possibility to do yourself. Sure the Atmel chips (I'm asuming ARM because CE and Linux run on ARM) would work fine though to be useable you'd have to put some sram and as you say a flash chip, your costs are going to go up fast, and again you have to deal with designing the PCB and all the details behind that.

#### RobertRoss

##### Member

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>Sure the Atmel chips (I'm asuming ARM because CE and Linux run on ARM) would work fine >though to be useable you'd have to put some sram and as you say a flash chip, your costs >are going to go up fast, and again you have to deal with designing the PCB and all the >details behind that.

I am confused! Okay.... Isn't the ARM a microcontroller which has the sram in it? Would I absolutely need extra external sram and how much would be required?

Finest regards
Rib

##### Banned
You're the one that has to determine how much RAM it needs Ross I'm not building it Sure you could use just the ARM chip but I don't know how much memory the chip you're planning on using has or how much CE or Linux take up on it. Also I don't particularly think of ARM's as micro controllers more microprocessor but that's a semantics thing.

I'd use Linux seeing as how you can actually get source code for it, trying to get CE to work on it would be a nightmare, I believe there is quiet a bit of code out there for Linux that works on ARMs there's a full GNU toolchain for ARM so that'd let you do C code, but you'd have to do all the device drivers and kernel building yourself. Not an easy undertaking.

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#### RobertRoss

##### Member
I was wondering... typically, how much ram does a Linux system require? I wouldn't know right now. I am just trying to establish a budget.

So just to make sure, you say that these microcontrollers offered by Atmel and soforth absolutely need external sram... right?

On another note, I thankyou very much for your sincere help.... it is much appreciated!

Rob

##### Banned
ARM Linux - Documentation
check it out.
I looked in the pre-built kernel directory, and it looks like it takes up approximatly 400-500k of memory just for the kernel.
Booting ARM Linux

Those are a few links I found with google, I'm sure there's tons more info out there. No idea how much memory Atmel's ARM chicps hve built in, but I can almost garuntee you're going to want more. I think the main purpose of ARM linux is for doing linux on WINCE handhelds that have ARM chips for people that want their own custom micro PC's, may be an option for you, all the works effectivly done for you already, all you have to do is find a PDA that has a lot of supported hardware, more searching on google may net you better results. for a 1.5" form factor though I'm pretty sure you're dead in the water, though it's more than plausible to use something like an AVR micro controller as a display driver and maybe a couple of micro RF modules (like from sparkfun) to make a wireless monitor that could communicate with pretty much any system. The sparkfun micro transmitters are rediculously small, and an AVR wouldn't need much but a crystal and a bit of coding to act as a display driver. Well maybe more than a bit of code =)

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#### RobertRoss

##### Member
Thanks Buddy, I really appreicate your sincere effort!

Finest reagrds
Roberto

#### dknguyen

##### Well-Known Member
I call a processor anything that requires external memory. I call a microcontroller anything that has internal memory. But yes, there is a grey area between the two. Another definition is that a microcontroller has everything it needs to run integrated into the package (like memory) while a processor does not.

Many times, a processor only works with digital data directly and cannot process analog signals (has no integrated ADC), while a microcontroller does. Actually...I've never seen a processor that has an ADC integrated into it but it's definately possible.

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#### RobertRoss

##### Member
...

Let me try to rephrase my question:

Can the above system be built using parts that would not total to more than 8$(TFT LCD, touchscreen and power supply excluded) ? I can be flexible and go 2" x 2" pc board! finest regrads! P.S. Its a yes/no question! Last edited: #### dknguyen ##### Well-Known Member Most Helpful Member THe answer is most definately not. Last edited: #### RobertRoss ##### Member ... hello, dknguyen Like I dscussed here with a very nice gentlemen before, I have seen ARM microcontrollers that can execute the Linux kernel installed on 2 mb of flash (sram). Then all I would need is the microcontroller @ 5$ and 2 mb of parallel flash @ 3$. In all due respect dknguyen, why do you say no. Remember all I am asking for is the bare bones hardware requirements. I am not talking about any development tools or LCD or touch screen or power supply or any DC to DC convertor component costs. Neither am I including the pc board here.... just bare bones micro controller system requirements! Finest regards Robert #### DirtyLude ##### Well-Known Member No. uC, memory, supporting components, power regulator, connectors, PCB = more than$8, even if mass produced.

(tried entering just 'no', but the message was too short)

..also you would need a touchscreen controller for proper touchscreen, like a TSC2007 or TSC2046.

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#### RobertRoss

##### Member
....

Mark:

Perhaps I was unclear.

I am only talking about the costs of the following two parts:

uC and required memory to run Linux...... that's it..... that's all I want in the quote!

r

#### DirtyLude

##### Well-Known Member
Your request makes no sense, since the chip is useless without at least the crystal and supporting caps, and the PLL.

On it's own. the AT91SAM9260 that you linked to is \$8.60 at Digikey for a quantity order of 3000.

Your requirement calls for two types of memory, FLASH ram for graphics and OS storage and SRAM for working memory.

Like I said, you need a touchscreen controller as well if you want precise touchscreen measurements. This is a chip that will need to be on your board, it's not the actual touchscreen, or part of the touchscreen.

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