Microcontroller ... which one ??

Hello, I am thinking of buiying this graphic display.

It has a 4 analog I/O for the touch screen, and 18 I/O (the specidications are on the link "Data Sheet") I have a VERY hard time trying to figure the best microcontroller to interface it with a desktop computer on the serial port. If you could take a look at (Microcontrollers section) and tell me wich one is the easiest / most efficient, i would appreciate big time ! Thanks guys!

Ok , the microcontroller should interpret the touch on the screen and also receive infos from the computer through the RS232 port It's just an Graphic display, and it is touch screen. So pretty much it is to send the places where it has been touched to the computer, and send the infos to be displayed from the computer..

That means Atmel all the way.

If this is a one-off project that can afford $20 for a chip, you can save yourself a lot of headscratching over selection tables and go with the highest-end Atmel part, which I believe is still the AtMEGA128. It is directly programmable in C/C++ with the free AVR-GCC compiler. Google is your friend, and Digi-Key is your dealer.

-- jm

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Hey thanks for the different options. My first choice is C of course, and after it's ASM... NO way ICD2 ... I don't even know what it is lol :) The other important thing is that it has to have an A/D converter (for the touch screen part). Someone told me to use also AMTEL actually ... But there are so many choices... I checled the PIC 18F ... that's like 64 I/O ... what for ? I have 4 Analog and 18 I/O for the display ... We are very limited on our budget too ... So i am trying to make it as low as i can... the compilers should not be a problem, I am sure we have what we need at school , or i can dl some clone or something I guess... That's not the problem :)

Great, you are the chief :) AtMega 128 is exactly what someoen else told me !! :)

Yes you rulezz ! :) Thannks !

Digikey ... I love them yea :)

It's hard to go wrong with the PIC's, the PIC18F series is great, however you would need a programmer like the ICD2 to work with it efficiently. Microchip and Atmel provide great free tools for assembly language, however if you want a c compiler the good ones cost money. If want C and can live with some restrictions, I think you could do your project using the TI 420 chips, and they have a cheap starter that comes with C. Another choice is using the Rabbit Chips.

I know not much help, but just about any of the chips can do your intended function, so asking how you want to create the software is a good distinction.

I checked and can see that the PIC and Atmel clocked serial modes will work with that display, that beats bit banging it out I don't know much about the TI chips as I have never used them.

Rocky

After playing around with one (admittedly on NEC's evaluation kit which I then subsumed into a project for a client) I'd strongly recommend the 32 bit RISC from NEC, the V850ES series.

Unlike the ARM design which only has 16 GP registers, the 850 has 32. From what I can make out, it seems to be strongly relate to the previous MIPS range of super-computers.

If you want to program it in C, be sure to pick one with 8, 16 or 32 bit registers and a single adress space (like the Hitachi H8 or the Texas instruments MSP430 series) otherwise you will find yourself writing all kinds of (non portable) functions which are already in the standard C library.

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Try

to select a PIC micro.

Try:

for an excellent PIC Basic compiler.

SF

If you know verilog, why not use verilog and a cpld ?

Hey, thanks for the website, I am not sure however for all the options because i am not sure what my design exactly needs to connect it to the RS232

This is what I want to do : The display is divided for example in 4 sections. In each row there is like a text. For example : First row: "Hello This is..." Next row "I love electronics" , Next row "I love you" Next row "I love hockey"

and one last row with and arrow

What I want to do : When I am typing something for example, in wordpad, and when I hit with my finger the first row, the whole text "Hello This is.." get copied ... Or if I do "I love electronics" the whole text get copied ... AND when I hit the arrow, it will go to another set of quotes.

Thanks for the help !

Just make sure what ever you choose has enough IO.

Your going to need 24 IO at minimum + other functions you may want like serial(rs232) connection so - 22 for the screen , 2 for usart tx and rx assuming you want to use the touchscreen ?

• maybe a temp sensor ? (is this for a fan controller/pc monitor ?)

also what are you going to display / run on the screen ? Will it need updating often ?

pic , avr, msp430, arm7(philips , sharp etc) , 8051, scenix or even basic stamp

Either pick one you have some knowledge of or one that has the cheapest and easiest to use tools

Also what package do you want to work with ? dip or surface mount ?

What language are you looking to us ? asm , c , basic , forth , pascal ?

pic has free forth , pascal(jal) and c compilers(limited versions of commerical product) asm is free

avr has free forth c and basic compilers(bascom avr lite - limited version) asm is free

same with msp430 , 8051 and arm7(made by a varitety of manufacturers).

Depending on your requirements maybe a atmega16, or 32 or 162 or pic16f877/877A pic18f452 , 448 , 442 , 458

some cheap boards here

even Philips lpc2106 or lpc2129

For pics

Avr

Alex

I have the touch screen, and display system

This is number one, it has to be done through a microcontroller

When I touch the arrow, I want another set of sentences to be sent (so computer sends a new set of 4 rows of different text)

Again, I have already the display. The microcontroller, i don't know which one to get.

Would you know how to connect the whole thing ? Display = > Micronctroller = > RS232 ?

Really the most important is part of the whole thing is not the display , but the whole "communication" aspect, meaning the interaction thing. In realliy i don't want to display for example 4 rows there and thee , but maybe 5 rows... But this I would know how to handle from the source code... You see what I mean kind of ?

Hey, What about the ATMega128 ? Can I use the existing librairies ? I want to write the less code possible. The problem is that I instead of doing a project proposed by the school... wanted to do something of my own ... but I think I aimed a bit too high !! :( I thought it would have been easier to hook a graphic display to a computer ! So I want the easiest way possible ! :)

Ok, the touchscreen is like an input for the RS232 port. And it is a 4 wire system. And there are 18 other inputs... So for sure , there are 22 , + more ? yes i want to use RS232 too.

The computer will send through the RS232 port the display. It won't change often at all. This is what I want to do : The display is divided for example in 4 sections. In each row there is like a text. For example : First row: "Hello This is..." Next row "I love electronics" , Next row "I love you" Next row "I love hockey"

and one last row with and arrow.

What I want to do : When I am typing something for example, in wordpad, and when I hit with my finger the first row, the whole text "Hello This is.." get copied ... Or if I do "I love electronics" the whole text get copied ... AND when I hit the arrow, it will go to another set of quotes.

Now i thought this was gonna be easy ... But no :) So as you see it does not a lot of updating at all .. just when you hit the next row I guess.

That is exactly why I asked the question on the forum ,is to try to figure out which one would be the easiest ! : / I don't know any of these controllers. I want the one doing the best the job and the easiest for me. I know we can use C , or ASM , .... I know programming, (C, ASM ...) . I think C is the way to go ? For the librairies and all that ?

Now I never heard of this terminilogy ? Does that mean that the controller comes without anything, or with a borad or something ?

I would avoid asm, but c, basic, forth, pascal are pretty much alike ... I guess C has the most suport ?

Someone already adised me to use AtMega 128 ... do you think it's good depending of everything I said above ? Thank you a lot for your help

Thanks, but I don't really know RISC ... : |

Ok , the microcontroller should interpret the touch on the screen and also receive infos from the computer through the RS232 port It's just an Graphic display, and it is touch screen. So pretty much it is to send the places where it has been touched to the computer, and send the infos to be displayed from the computer..

The Mega128 is a very capable processor. You are unlikely to find canned libraries to talk to your display, but for all the on-chip peripherals, yes.

That's sort of nonsensical, don't you think? RISC is not a language. RISC is a marketing term, trying to make an advantage out of limited instruction space.

Ex: The PIC is "risc", and the AVR is considered "CISC". The Pic should be faster right?

At the same clock, the PIC takes four cycles to do anything, while most instructions on the AVR are one cycle. The PIC clocks a bit faster than the AVR, but nowhere near enough to make it up. Barely 2x, and they'd need at least 4X.

Since the PIC has less instructions, a given function requires more instructions to get done. Also, the PIC has a single working register, where the AVR has 32, though the lower 16 are slightly limited. Where the AVR can store many critical things in registers, and modify/test them in one cycle, the PIC needs to load them into the W register (four cycles) test (four cycles) then save them back if it was a modify, for another four cycles.

So it would seem that the overwhelming advantage is to the "CISC" machine.

Remember, the limit case of RISC is a processor that has one "NOP" instruction, but executes it infinitely fast.