Why do we still have serial ports?

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Migs

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Friends:

I just don't get it. It seems every embeddable device out there from micro controller boards, to ZigBees, to Blue Smirfs to ... ALL have serial ports, but no modern computer has these ports. (They all have USB)

Thus we are all forced to have an adapter on our cable and some drivers installed just to use them.

Why hasn't the industry realized this and changed accordingly?

Frustrated, -Migs
 
Serial ports

Hi Migs,

PCs still do have at least one serial port. However they are omitted in Laptops. Even in times when they were built into Laptops the port wasn't complete. They just had RxD, TxD and GND which are insufficient programming an industrial SPS - they require a two-way communication.

The only way out is an extra USB to RS232 converter increasing the number of peripherals instead of reducing them.

Boncuk
 
Personally, it drives me nuts that laptops *don't* come with a serial port anymore. It's the only thing I don't like about my new machine (well, that and the crappy speakers). The serial port is easy to program for, easy to build hardware for, and just easy to use in general. Plus, lots of stuff has it. No way do I want to have to get rid of all my older stuff just because there are newer things available.


Torben
 
Boncuk said:
...
Even in times when they were built into Laptops the port wasn't complete. They just had RxD, TxD and GND which are insufficient programming an industrial SPS - they require a two-way communication.
Click to expand...
This is most certainly not true. They may not have filled up a DB-9 connector but at least some of the modem control signals were there. How many of them do you need anyway if you're not talking to a Bell modem.
 
because they are the mutts nuts ........ im using one in my project, and its such a pain that my laptop doesnt have a serial port, because i am using the uart of the pic for communication. because of this i need to use a usb-serial dongle and create a virtual serial port. i guess they use it on laptops to save space, and also, usb devices can power themselves off the pc. most serial devices cant
 
Serial ports are great. No complicated communications, they are extremely cheap to implement, and there is a massive installed base of equipment out there using them. Best of all, you get to forget about drivers, its not OS dependant, and very forgiving. Serial ports are like cash money. Everybody understands cash, and is willing to deal in cash.

We have GSM and CDMA wireless data modems at work that use a serial port to connect to anything from an $40,000 embedded system to the equivalent of a i386 pc installed in the 80's. They communicate flawlessly accross country without hassle.

Maybe it is really old technology, but sometimes when you just need to get a job done, a stone hammer is the tool for the job.
 
Migs,

Once you have tried to use USB on a microcontroller then you will understand why (almost) everyone that has experience on a micro prefers RS232 type serial.

Mike.
 
You can use a PCI to SERIAL interface card. I have one in my computer.
They supports standard and nonstandard baud rates.

So better learn first RS232 Communication as Mike suggests.
 
Pommie said:
Migs,

Once you have tried to use USB on a microcontroller then you will understand why (almost) everyone that has experience on a micro prefers RS232 type serial.

Mike.
Click to expand...
Well said. RS232 style serial is so simple you can get it working on most any processor. USB takes a lot of processor by comparison.

Disclaimer: I have never tried bit banging serial on a 4 bit processor.
 
Technology obsolescence should not force us to replace each and every thing we have been so far using. They have give reasonable time and advance notices before abandoning older connector standards.

Somehow it has become an industry gimmick.

Certain software, for example, older version of Easy PC from Number One Systems of UK, becomes problematic the moment the parallel ports are abandoned in the PC and USB printers took over.
I know of some elderly person facing this issue right in UK, and for this purpose, we can't force him abandon his old software and purchase new versions.
 
hi,
The advantage I find with RS232, is the distance/length of the [basic 3 core] interconnection cable.
A bog standard cable with RS232 can be used upto 100ft with no problems, longer, if extra care is taken.

Many industrial dataloggers still use RS232, with a full RS232 spec and a decent screened cable any noise problems are minimal.
 
Don't look now, but USB is serial. Only the Centronics printer port is parallel. If you look at controllers, A-D converters, digital pots, etc., most have serial control input, not parallel. Cuts down on number of pins. Theory says that parallel should be faster because you're passing 8, 16 or 32 bits at a time instead of one. But the world is moving serial. Firewire, etc. You speak serially. It's only within the computer itself that everything goes parallel, and a lot of that is going serial in controllers.

Dean
 
I got a newer 939 gigabyte board and it's still got 1 parallel, and 2 serials, not that I really use them for anything. I do use the parallel every now and then for my old microtek scanner, my god you should see even a 3 ghz cpu and 1.5 gig memory computer act like a 386 when you scan using the parallel interface.
 
Dean Huster said:
Theory says that parallel should be faster because you're passing 8, 16 or 32 bits at a time instead of one.
Click to expand...
And theory is dead right. Just a shame that you can't guarantee them all arriving at the same time. Otherwise we wouldn't have to complain that our external drives transfer data back and worth way too slow.

Edit: Oh I just remembered. My motherboard lacks serial and parallel ports by default but it does have pins. Still - they're disappearing in favor of more USB and LAN ports.
 
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