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Hey all,
I am doing a project on Vehicle Tracking System using GPS and GSM Modem.The 2 devices aforementioned communicates with 8051uC. But since there is only 1 UART in 8051 i have to use a analog multiplexer i.e CD 4062. I want to know how to interface it with GPS, GSM, and 8051.
Also it would be grateful if anyone could tell me how to parse output of GPS and how initialize a GPS receiver to that it starts giving me the GPRMC
Yes I know about DS80C400 having 3 UARTS but in the previous thread forgot to metion 3 UARTS + ISP. NO MCU with 3 UARTS + ISP.
Also Pls help me with what is called as ON CHIP DEBUG
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This is pretty well self descriptive!
It means that the chip has debug hardware built-in.
This means that a debugger can directly access the "internals" of the chip - CPU registers, memory, etc - without needing any special software running on the chip.
Without on-chip debug, the only way to gain such access was to remove the chip and physically replace it with an In-Circuit Emulator - or "ICE" for short. Hence on-chip debug is often referred to (not entirely accurately) as "on-chip ICE".
Why?
You say that you can't find any 8051-family chips that meet your requirements; so why are you "keen" to use a family that doesn't meet your needs - especially when other families so clearly do!
OR, do you actually mean that you already know the 8051 architecture, and have the tools, and don't (think you) have time to learn a new one? That could be a good reason to stick with 8051, but you really need to be clear about the pros and cons - and not just make vague statements like, "I am keen on..."
Correctly said that I actually mean that you already know the 8051 architecture, and have the tools hence i am keen on working with 8051 family.
Also Pls help me with the selection of GPS. What parameters should i look for in my GPS receiver. One of my friends told me that look for GPS with 20 or more channels What does this statement exactly mean? What all parameters should i look for before buying a GPS receiver
More channels are obviously nice, but maybe even nicer: - a receiver that supports multiple satellite systems (GLONASS or maybe upcomming Galileo, ...) - a receiver that very quickly locks on. - a receiver that allows use of a super-cap or battery to keep information (last position, ephemeris) even when you turn off your equipment - this allows for faster tracking when you turn it on - a receiver with high sensitivity - a receiver with extended precision, supporting WAAS, EGNOS or similar. - a receiver that can emit multiple positions every second, to reduce problems with lag. - a receiver that supports the specific NMEA strings you want - or maybe you prefer SiRF Binary? - direct support for powering an active antenna. - low power consumption. - "correct" supply voltage. - suitable form factor. - ...
There are a huge number of parameters to think about when selecting a GPS. Number of channels it can track is just a single parameter.
What do we mean by Extended RAM (XRAM).It was stated in the AT89C51RE2 data sheet that it has On-chip 8192 bytes Expanded RAM (XRAM) – Software Selectable Size (0, 256, 512, 768, 1024, 1792, 2048, 4096, 8192 bytes)
When i tried Googling it the info was reagrding X-fi and XRAM used in games. I couldn't make out the difference between XRAM and other normally used RAMs
Pls Help
I thought you said you were familiar with the 8051 architecture?!
XRAM, in the context of an 8051, is memory accessed by the MOVX instruction.
It was originally called 'X' for eXternal - because it was physically external to the 8051 chip.
Nowadays, most 8051-derivatives have at least some MOVX-addresses memory on-chip - so some people (including some chipmakers) fudge the issue by trying to give it different names.
As far as the CPU - and, therefore, your code - is concerned, it is all just MOVX-addressed memory; it is irrelevant whether it is physically on or off the chip.
What do we mean by Extended RAM (XRAM).
The fact that you ask this puts the lie to your earlier claim that you were keen on using an 8051 because you "knew the architecture". You clearly don't.
"The fact that you ask this puts the lie to your earlier claim that you were keen on using an 8051 because you "knew the architecture". You clearly don't."
The reason why I asked you this because if it is XRAM it was external to the chip.But now since the datasheets say"ON CHIP XRAM" I was a little bit confused if its ON CHIP why is it "X".
Pls consider me worthy of something. Sometimes the question may sound too foolish but it is of great importance to someone
No - it is you who need to demonstrate that you are worthy of something!
You claimed to be familiar with the 8051 family - but your this clearly shows that you are not!
It is a very long time indeed since the "external" in XRAM meant literally external from the chip!
Even so, the AT89C51RE2 datasheet does clearly state what it means by "XRAM" - in the section headed, unsurprisingly, "Expanded RAM (XRAM)":
"4. The expanded RAM bytes are indirectly accessed by MOVX instructions"
and:
"The XRAM bytes can be accessed by indirect addressing, with EXTRAM bit cleared and MOVX instructions. This part of memory which is physically located on-chip, logically occupies the first bytes of external data memory."
See page 22: www.atmel.com/.../doc7663.pdf
You really need to study the whole datasheet; the bullet points on the front page are just highlights - they obviously cannot give a full description!
What are MOVX instructions
You're kidding, right??
You claimed that you were familiar with the 8051.
More than that, you claimed that you were so familiar with the 8051 that learning another architecture - even when other architectures would give you chips better suited to your task - was a sufficient reason to stick (sic?) with the 8051.
You clearly need to start with the very basics: http://www.8052.com/tut8051 www.8052.com/.../120112
And, again, http://www.keil.com/books/8051books.asp
Ok now you got me. Listen what i need to learn is just nothing. I know it all
I know it all
Yes, Mohammed, you most definitely do. You have no idea about memory types in the architecture that you are so "keen" on working with (are you sure you know what "keen" means?). You don't know what MOVX does. You miss fundamental, universal knowledge that is absolutely compulsory to even start with embedded programming (or programming altogether!). But yet again, you know it all. What a waste of time!
It sounds like it would be better for you to consider a Cortex M3 chip - it has a similar price, low power consumption, better performance and...a more generic programming model.