WiFi as serial connection?

[SherpaDoug]

Since RS232 ports are becoming scarce on PCs, many of us are looking for other ways of communicating with our little projects. USB and Ethernet both have a lot of overhead unless you buy someone else's adapter module. If I am going to go to that much bother, how about WiFi?

Does anyone have a Dumb WiFi Terminal program that could sent bytes or packets via WiFi to a PIC project and display data it gets back? Or is there some computing concept here I am missing? I think I could handle the RF and PIC end, but writing PC software I would rather avoid.

I like the idea that I could hand my product to an end used and they could use any modern PC to talk to it without buying and installing adapters or even wires!
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The search for better is endless. Instead simply find very good and get the job done.

[asmboy]

Perhaps what you seek?

http://www.sparkfun.com/products/158

[asmboy]

here is the whole kit an kaboodle from sparkfun

http://www.sparkfun.com/categories/16

[SherpaDoug]

Well this idea looks like it merits further research! I didn't know you could get 100 meters from Bluetooth, so I was thinking I needed WiFi for 10' or 20' range.

But first I will have to see how to get SIO, Terminal, or Realterm to talk to my laptop's Bluetooth.

Thank you asmboy!
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The search for better is endless. Instead simply find very good and get the job done.

[gpsmikey]

Be sure and look into the ZigBee stuff as well - those modules are pretty cool, relatively inexpensive and can link over some pretty good distances depending on which version you get. Here are a couple of links:

http://www.digi.com/pdf/ds_xbeezbmodules.pdf
http://www.sparkfun.com/products/10414


mikey
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mikey
-- you can't have too many gadgets or too much disk space !
old engineering saying: 1+1 = 3 for sufficiently large values of 1 or small values of 3

[SherpaDoug]

Do any COTS laptops support Zigbee out of the box, without USB dongles or adapters? If I have to use an adapter I might as well stick with RS232.

Not all laptops support Bluetooth, but many do. WiFi seems to be the most universal.
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The search for better is endless. Instead simply find very good and get the job done.

[andrewg]

USB would have to be the simplest, particularly with USB PICs, and I don't consider that it has a lot of overhead, less than 5K for the CDC code looking at one of my recent projects. USB *is* more complex than RS232, but all you need to do is plan for that extra code at the start.

The next simplest is an external USB/RS232 chip, like the FT232 or MCP2200.

After that is Bluetooth. Most laptops have it integrated. The point-to-point nature of it makes it simple to configure and use too. Bluetooth/serial modules are readily available.

Wi-Fi is relatively complex and power-hungry. I've not used it with microcontrollers, but I can say that it will be much more complicated for the end-user to setup. Your project will need to have enough UI (or some other means of configuration) so that the user can set the network SSID, network password, network type (WEP/WPA/WPA2), IP type (static vs dynamic), IP address (only if static, eg 192.168.1.123), DNS IP address (optional). i.e. you'll either need a screen and buttons for data entry, or something like an SD card with a config file.

That's just to establish a Wi-Fi connection to the network. Ethernet is similar, except it doesn't have the SSID, password and type items. Once you've done that, the user needs to connect to the device. A web interface is very nice for the end user. For software interface, I've either developed my own custom TCP/UDP protocols or implemented RFC2217 (Telnet COM Port) and used the free HW Virtual Serial Port.

If you Google for "wifi rfc2217" you should turn up a few devices, but I suspect they're all rather expensive.
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Andrew

[asmboy]

For all the reasons i mentioned in my first response - blue tooth mediated RS-232 protocol - is my #1 approach for this.

The extra software overhead and IP stack oriented basis of "wifi" is not gonna be feasible in a small memory model pic IMHO. And further the tendency to rely on SPI serial interfacing for ISM/GSM transceivers will be a deal breaker too - if a simple TTL serial TX/RX baudot code flip is what you seek.

That said - I personally still use wired connects albeit via USB using the FTDI UM232R modules - all the time.
As a bonus - you can steal a bit of 5V from the USB host for a simple pic code test too.

http://www.mouser.com/ProductDetail/FTDI/UM232R/?qs=Xb8IjHhkxj55I%2Fi97zZKYA%3D%3D

[SherpaDoug]

I think I am going to persue the bluetooth path for now.
Thanks guys!
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The search for better is endless. Instead simply find very good and get the job done.

[arunb]

Use gumstix (http://www.gumstix.com/store/product_info.php?products_id=226), it may be expensive.