 Micro Processor |
haik4096
Newbie
Registration Date: 18-12-2009
Posts: 3
 |
|
Hi,
I'm wanting to design an embedded system which will control a vehicle. I'm struggling as to where to start, i bought a book called "designing embedded hardware" however it was of limited use in answering some simple questions as to where to start from;
I'm looking to design a vehicle which will receive input from approx 50 sensors, the processing unit will then perform routine operations on this information to give output to two motors and several servo's. For the vehicle to drive around a predetermined route which is marked out on the ground, like automated vehicles in airports. The processing unit also needs to communicate with a host computer over a wireless network to recieve basic instructions as to where to go next. Storing this information as it goes along. THe unit will be battery powered, so power consumption is an issue however not imperatice as the vehicle will have a facility for recharging overnight and a large onboard battery pack sufficient for the vehicle do drive 2 miles.
I have a basic electronics education, and have done some basic PIC programming in the past for recieving input from sensors and outputting that to two electric motors to drive an unmanned vehicle. However PIC's have no where near the complexity i need.
My basic question is where do i start, i've researched microcontrollers/microprocessors however i haven't been able to find anything suitable or a microntroller complicated to run anything more than a digital watch. I've seen entire units with the processor sat in the middle and various memory modules pre soldered to the board around it, with serial interfaces etc. Does anyone know anything about these.
I don't know whether i need to design my processing unit from scratch, i.e buy a CPU and go from there attaching memory/serial ports as and when needed etc....or to simply buy a unit which i can program from my PC using C or C++ to get the unit to do what i want. And attach all the relevant inputs/ outputs to it.
I've looked into basic microcontrollers such as Atmel, PIC, 8041, Motorola etc...i'm not really sure which way to go and don't really want to spend the money on any more textbooks before i know whihc direction i need to start off from.
I have a lot of inputs/outputs, however i could reduce these using PIC's and logic gates before the signal is fed into the processing unit as i have noticed that most microcontrollers seem to max out at about 32 I/O pins.
If someone could give me a direction from which to go or a microprocessor family which would be most suitable that would be amazing.
The embedded system part of my design is not the most important so i'm not so fussed about buying a pre made processing unit if it makes life easier. I'm not interested in programming in any assembley languages or adressing memory allocations etc. I'd much prefer to simply work with a pre debugged unit and only have to work in the high level language. However i am prepared to start from absolute scratch if necessary working with a processing unit which it is easy to add extra modules to such as memory.
I have come accross all sorts of development tools such as compilers, programmers etc and the need to program a device in circuit. i.e i can't simply breadboard up a device i need to do development work on PCB which wold cost money.
I envisage needing to buy a suitable oscilloscope, etc however my budget can't stretch much more than �1000 for a fully working circuit doing exactly what i need it to do including all the tools i need etc. Not including the vehicle itself.
I do have some programming knowledge in languages other than C or C++ however i think i could work with them quite well.
Heres a breakdown of my system if it helps;
Inputs; a range of sensors decting almost everything in the immediate environment.
Outputs; Motors, servo's, possibly speech and audio alarms.
Interfaces; Wirless over a range of 2 miles to communicate with the host computer. Possibly a GPS module to send the the vehciles location to the host computer over wireless. Some sort of serial output port to directly connect to a laptop for diagnostic checking/downloading the vehicles route history/diagnostics etc.
Memory, onboard ROM or equivelant memory for storing the program size of about 512k. Some sort of flash memory for storing information about the vehicles journey of about 2Mb total.
I've got experience with all the other circuit functions such as sensors, power supplies, motor & servo control its just the building block of the processing unit i need to start with. Something with the grunt and versatility would be great, that is adaptable to a range of inputs and outputs. And also has the capability for expansion at a later date if i start running out of memory for program storage or something like that.
Something that would drain a car battery in 10 minutes would be useless for me, at least two days of operation before it finishes one.
Speed is not essential, however i don't want the vehicle stopping for 2 minutes while it catches up with it's processes. Real time is essential.
I've come accross 8-bit, 16-bit, 32 - bit processors, it seems like the bit size is the amount of memory allocations it can adress or something.
If anyone can give me any help or a direction to find the information i need i would be really grateful. Please post only constructive information. I can fully appreciate i'm well over my head in this. However the embedded system part of my project is only a means to an end, it doesn't need to be a work of art. THe rest of the vehicle is what is where my expertise comes in. I'm fully prepared to do everything that needs to be done to get this to work even if it means hundreds of hours of research.
I'll check this later, any questions i'll reply straight away, i know this reads a bit of a mess so i'm happy to clarify anything in more detail.
regards,
Haik
__
carte sdhc 32gb
|
|
|
21-12-2009 06:18 |
|
|
Muad'Dib 
Andrejnalin
Registration Date: 02-12-2003
Posts: 4,197
Helpfulness rating:
|
|
Well, you can try seeking up CPUs that are used in handheld PCs and PDAs (Monahans is the first that comes to mind now).
They have the complexity of regular PC CPUs and have very low power consumption, and are already peaking at 1000 mhz (processing speed).
I have a PDA, and with 1440 mHa battery it holds 5 days of mid usage (phone, mobile windows, calculations, listening to music. etc) so, you might wanna check them out.
Can't guide you much further, but I am very interesting what will come off of this project of yours 
__
Thinking about becoming an Image-Line/FL Studio customer? Want a 10% reduction in price? Use this affiliate link:
http://affiliate.image-line.com/BADEBDG473
There is no such thing without its opposite
-Bene Gesserit
|
|
|
21-12-2009 13:53 |
|
|
|
