Post by thread:[PIC] HTML to browser over EIA232?

I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC projects. Is there any way to direct a URL request from a browser to a COMM port? Say, instead of the or file:// prefix, we did a com1:// prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of sending the request out to the specified IP address over ethernet, it'd send the GET or POST request out the specified EIA232 port. Our PIC would just respond to the request. The mydevice in the above URL would be meaningless, though perhaps the PIC device could ignore requests not addressed to it (not respond), allowing other devices on a tri-state or open collector EIA232 bus to respond. I've done "open collector" EIA232 buses by having a pull-down to -12 and a diode between the driver and the bus. Any device can drive the bus positive (space condition), and the bus idles at -12V (mark condition). This would be a master/slave arrangement, since no device gets on the bus unless asked for a response, so contention would not be an issue. So, any "wedge" or something that can be put on a Windoze machine so a URL prefix of com1: com2: etc. would work? Just kicking around the idea. THANKS! Harold -- FCC Rules Updated Daily at http://www.hallikainen.com

Harold, your best bet might be to look at a very minimalistic web server (i believe busybox has one, for example), and then modify it for your purposes. You can let it run in the background, listening to requests on, say, localhost:81, and forwarding them appropriately to the serial device. - Marcel "Harold Hallikainen" <spam_OUTharoldTakeThisOuThallikainen.com> wrote: {Quote hidden}> I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > sending the request out to the specified IP address over ethernet, it'd > send the GET or POST request out the specified EIA232 port. Our PIC would > just respond to the request. The mydevice in the above URL would be > meaningless, though perhaps the PIC device could ignore requests not > addressed to it (not respond), allowing other devices on a tri-state or > open collector EIA232 bus to respond. I've done "open collector" EIA232 > buses by having a pull-down to -12 and a diode between the driver and the > bus. Any device can drive the bus positive (space condition), and the bus > idles at -12V (mark condition). This would be a master/slave arrangement, > since no device gets on the bus unless asked for a response, so contention > would not be an issue. > > So, any "wedge" or something that can be put on a Windoze machine so a URL > prefix of com1: com2: etc. would work? > > Just kicking around the idea. > > THANKS! > > Harold > >

Harold, your best bet might be to look at a very minimalistic web server (i believe busybox has one, for example), and then modify it for your purposes. You can let it run in the background, listening to requests on, say, localhost:81, and forwarding them appropriately to the serial device. - Marcel "Harold Hallikainen" <.....haroldKILLspam@spam@hallikainen.com> wrote: {Quote hidden}> I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > sending the request out to the specified IP address over ethernet, it'd > send the GET or POST request out the specified EIA232 port. Our PIC would > just respond to the request. The mydevice in the above URL would be > meaningless, though perhaps the PIC device could ignore requests not > addressed to it (not respond), allowing other devices on a tri-state or > open collector EIA232 bus to respond. I've done "open collector" EIA232 > buses by having a pull-down to -12 and a diode between the driver and the > bus. Any device can drive the bus positive (space condition), and the bus > idles at -12V (mark condition). This would be a master/slave arrangement, > since no device gets on the bus unless asked for a response, so contention > would not be an issue. > > So, any "wedge" or something that can be put on a Windoze machine so a URL > prefix of com1: com2: etc. would work? > > Just kicking around the idea. > > THANKS! > > Harold > >

Rochester, 27 september 2005. Dear Harold, From your description I assume you want to keep it simple on the Windows side, but don't care about the complexity on the PIC side. There might be simpler methods, but the one I came up with was using SLIP: at the windows side this would just involve doing "Add New Connection" -> "Connect directly to another computer" -> "Guest" -> "COM1" -> Properties -> Networking -> SLIP. Don't forget to set an IP address. Of course, implementing SLIP on the PIC might not be easy (though it is a fairly simple protocol, it would imply implementing TCP/IP as well, at least to the point where you can accept WWW requests, as well as the WWW server) but it would keep things quite simple on the Windows side. RFC 1055 contains more information about SLIP. It might be possible to use SLIP to multiple PICs connected the way you described, and even between PICs, but I doubt anyone has ever done it. Greetings, Maarten Hofman.

On Tue, 27 Sep 2005, Harold Hallikainen wrote: > I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? I think the biggest problem with this idea is that any modern browser is going to open multiple concurrent connections to the server. Those aren't going to multiplex over a serial link. One approach would be to run a SLIP link to the PIC. If you don't want a TCP/IP stack on the PIC, I don't see how you could do it without some additional code on the PC; some sort of proxy server that the browser would connect to and convert the connections to serialized requests over the COM port. -- John W. Temples, III

Harald, On Tue, 27 Sep 2005 13:04:20 -0700 (PDT), Harold Hallikainen wrote: > I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). You have to stick to the format of a URL - the part before the // is the *protocol* not any sort of address - com1 is an address. If you were going to do something like this there would need to be a new protocol defined (let's call it "ser:" for serial! :-) So you would have something like: ser://com1.mymachine/analog?chan=1 where: "com1" is the name of a serial port "mymachine" is the name of the machine the port is fitted to, and could be omitted if it's the machine you are running on "analog" and "chan" (and anything else beyond the final slash) are interpreted by the device on the serial port. Serial ports are generally single devices, but there's nothing to stop you adding further layers of addressing where the serial device connects onwards to other devices, say on a CAN bus, so you could have: ser://com1/CAN04/temp1?read if say you wanted device number 4 on the CAN bus to read temperature 1 and return the result, all accessed via the serial port. Now, just watch someone go and spoil the idea... :-) Cheers, Howard Winter St.Albans, England

Harold Hallikainen wrote: {Quote hidden}> I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > sending the request out to the specified IP address over ethernet, it'd > send the GET or POST request out the specified EIA232 port. Our PIC would > just respond to the request. The mydevice in the above URL would be > meaningless, though perhaps the PIC device could ignore requests not > addressed to it (not respond), allowing other devices on a tri-state or > open collector EIA232 bus to respond. I've done "open collector" EIA232 > buses by having a pull-down to -12 and a diode between the driver and the > bus. Any device can drive the bus positive (space condition), and the bus > idles at -12V (mark condition). This would be a master/slave arrangement, > since no device gets on the bus unless asked for a response, so contention > would not be an issue. > > So, any "wedge" or something that can be put on a Windoze machine so a URL > prefix of com1: com2: etc. would work? > > Just kicking around the idea. > > THANKS! > > Harold If I understand you correctly, you might meet your needs with a Lantronix Xport. It is a web server in a RJ45 connector with network on one side and a serial port on the other. It can repsond to wiggles on the serial port and send data to you over the network. It can even send an email. The host machine gets a comm port redirector program that allows you to configure the device like a remote comm port. An eval board is around $50 or $60US.

Harold Hallikainen writes: > I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > sending the request out to the specified IP address over ethernet, it'd > send the GET or POST request out the specified EIA232 port. Our PIC would ... Not exactly what you're asking for, but a web server supporting cgi-bin scripts (apache) or possibly some other form of server side scripting (php, mod-perl, mod-python) would allow URLs somethin like: http://localhost/cgi-bin/pic-wacker?port=com1?func=analog?chan=1 This has the advantage of being a real URL, so if you wound up using a tool where you had to choose from a spin-box for the protocol (http, ftp, file, etc.) you wouldn't get stuck because it doesn't know a protocol called com1. Another possibility is that the Python distribution (python.org, free), and I'm sure other tools like perl, comes with (or has available) a relativly small web server implementation in that language. It could easily be modified to apply suitable GET or POST requests, with whatever filtering/munging that you want, to com ports. You would still use an ordinary URL such as I suggest above, possibly on an IP port other than 80. Bill

> You have to stick to the format of a URL - the part before the // is the *protocol* not any sort of address - > com1 is an address. If you were going to do something like this there would need to be a new protocol defined > (let's call it "ser:" for serial! :-) I'd go with "serial:" I don't see any reason to abbreviate this. > So you would have something like: > > ser://com1.mymachine/analog?chan=1 > where: > "com1" is the name of a serial port > "mymachine" is the name of the machine the port is fitted to, and could be omitted if it's the machine you > are running on I can't picture using this URL on a different machine. Otherwise, I *love* it. -- D. Jay Newman ! Polititions and civilations come and jayKILLspamsprucegrove.com ! go but the engineers and machinists http://enerd.ws/robots/ ! make progress

It may not be exactly what you decribe but have a look at <http://www.easyvitools.com/index.html> he has a com port to browser interface & mini web server. Also tools for building a windows control panel that drives devices by serial ports or ethernet etc. You just use a BASIC style language to describe what you want. The downside is that it is a bit slow & there is minimal error checking so incorrect syntax just results in things not working, If you can find a copy of the earlier demo version ezcom2web server program it is less restricted than the later one. RP On 28/09/05, Marcel Duchamp <.....marcel.duchampKILLspam.....sbcglobal.net> wrote: {Quote hidden}> Harold Hallikainen wrote: > > I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > > projects. Is there any way to direct a URL request from a browser to a > > COMM port? Say, instead of the or file:// prefix, we did a com1:// > > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > > sending the request out to the specified IP address over ethernet, it'd > > send the GET or POST request out the specified EIA232 port. Our PIC would > > just respond to the request. The mydevice in the above URL would be > > meaningless, though perhaps the PIC device could ignore requests not > > addressed to it (not respond), allowing other devices on a tri-state or > > open collector EIA232 bus to respond. I've done "open collector" EIA232 > > buses by having a pull-down to -12 and a diode between the driver and the > > bus. Any device can drive the bus positive (space condition), and the bus > > idles at -12V (mark condition). This would be a master/slave arrangement, > > since no device gets on the bus unless asked for a response, so contention > > would not be an issue. > > > > So, any "wedge" or something that can be put on a Windoze machine so a URL > > prefix of com1: com2: etc. would work? > > > > Just kicking around the idea. > > > > THANKS! > > > > Harold > > If I understand you correctly, you might meet your needs with a > Lantronix Xport. It is a web server in a RJ45 connector with network on > one side and a serial port on the other. > > It can repsond to wiggles on the serial port and send data to you over > the network. It can even send an email. The host machine gets a comm > port redirector program that allows you to configure the device like a > remote comm port. An eval board is around $50 or $60US. > > -

On 27/09/2005, at 9:04 PM, Harold Hallikainen wrote: > COMM port? Say, instead of the or file:// prefix, we did a > com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of It should be something more like: serial://com1/ The protocol for talking to com2 would be the same as talking to com1 - its the address thats different. Feel free to substitute serial with some other string. Obviously no browser supports this as yet but I believe you could do it via a Mozilla/Firefox plugin. Overload user:password@host:port stuff to set baud rate etc. I think if you put it in the right place, you could serialise the requests within Firefox. Never done it myself of course :-) Andrew

At 04:04 PM 9/27/2005, Harold wrote: >I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC >projects. Is there any way to direct a URL request from a browser to a >COMM port? Say, instead of the or file:// prefix, we did a com1:// >prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of >sending the request out to the specified IP address over ethernet, it'd >send the GET or POST request out the specified EIA232 port. Our PIC would >just respond to the request. The mydevice in the above URL would be >meaningless, though perhaps the PIC device could ignore requests not >addressed to it (not respond), allowing other devices on a tri-state or >open collector EIA232 bus to respond. I've done "open collector" EIA232 >buses by having a pull-down to -12 and a diode between the driver and the >bus. Any device can drive the bus positive (space condition), and the bus >idles at -12V (mark condition). This would be a master/slave arrangement, >since no device gets on the bus unless asked for a response, so contention >would not be an issue. > >So, any "wedge" or something that can be put on a Windoze machine so a URL >prefix of com1: com2: etc. would work? I'm no expert, but I believe an IP address can be assigned to just about any device in Windows. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: EraseMEralspam_OUTTakeThisOuTlcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire" ================================================================

On 9/27/05, Harold Hallikainen <haroldspam_OUThallikainen.com> wrote: {Quote hidden}> I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > projects. Is there any way to direct a URL request from a browser to a > COMM port? Say, instead of the or file:// prefix, we did a com1:// > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > sending the request out to the specified IP address over ethernet, it'd > send the GET or POST request out the specified EIA232 port. Our PIC would > just respond to the request. The mydevice in the above URL would be > meaningless, though perhaps the PIC device could ignore requests not > addressed to it (not respond), allowing other devices on a tri-state or > open collector EIA232 bus to respond. I've done "open collector" EIA232 > buses by having a pull-down to -12 and a diode between the driver and the > bus. Any device can drive the bus positive (space condition), and the bus > idles at -12V (mark condition). This would be a master/slave arrangement, > since no device gets on the bus unless asked for a response, so contention > would not be an issue. > > So, any "wedge" or something that can be put on a Windoze machine so a URL > prefix of com1: com2: etc. would work? > > Just kicking around the idea. > > THANKS! You can make a simple Python web server in less than a screenful of code: http://fragments.turtlemeat.com/pythonwebserver.php Join the example given with the excellent pySerial project, and you get a cross-platform, network transparent GUI without much effort. I've done exactly this for some of our in-house projects. Very cool. (You might need to poke a hole in Windows firewall to access the interface from another computer.) Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie

THANKS for the comments thus far! I realize there are hardware approaches, such as serial to ethernet adapters (Lantronix, etc.). I'm wondering, though, of a purely software approach on the Windoze side. I've written a lot of cgi scripts, and the stuff the browser sends the cgi is pretty easy to deal with (even with a pic). The trick is to get the browser to send that directly to the pic (through a serial port) instead of through ethernet (or slip on the serial port). Just send the GET or POST request out the serial port and display what comes back. Since the exchange is all ascii, a PIC could handle it very cheaply without having to deal with slip, ethernet, or requiring additional hardware to deal with ethernet. Maybe if the OS treats a com port like a file, the URL could be file://com1/somethingOrAnother/?parameter1=123&parameter2=456 . Just playing around with the idea. Why convert to ethernet if we don't need to? Harold > Harold Hallikainen wrote: >> I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC projects. Is there any way to direct a URL request from a browser to a COMM port? Say, instead of the or file:// prefix, we did a com1:// >> prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of sending the request out to the specified IP address over ethernet, it'd send the GET or POST request out the specified EIA232 port. Our PIC would >> just respond to the request. The mydevice in the above URL would be meaningless, though perhaps the PIC device could ignore requests not addressed to it (not respond), allowing other devices on a tri-state or open collector EIA232 bus to respond. I've done "open collector" EIA232 buses by having a pull-down to -12 and a diode between the driver and the {Quote hidden}>> bus. Any device can drive the bus positive (space condition), and the bus >> idles at -12V (mark condition). This would be a master/slave >> arrangement, >> since no device gets on the bus unless asked for a response, so contention >> would not be an issue. >> So, any "wedge" or something that can be put on a Windoze machine so a URL >> prefix of com1: com2: etc. would work? >> Just kicking around the idea. >> THANKS! >> Harold > > If I understand you correctly, you might meet your needs with a > Lantronix Xport. It is a web server in a RJ45 connector with network on one side and a serial port on the other. > > It can repsond to wiggles on the serial port and send data to you over the network. It can even send an email. The host machine gets a comm port redirector program that allows you to configure the device like a remote comm port. An eval board is around $50 or $60US. > > -

Bill Freeman wrote: > Harold Hallikainen writes: > > I'm wondering about a cheap and dirty way to get a Windoze GUI for PIC > > projects. Is there any way to direct a URL request from a browser to a > > COMM port? Say, instead of the or file:// prefix, we did a com1:// > > prefix (perhaps a URL of com1://mydevice/analog?chan=1). Instead of > > sending the request out to the specified IP address over ethernet, it'd > > send the GET or POST request out the specified EIA232 port. Our PIC would > > Not exactly what you're asking for, but a web server > supporting cgi-bin scripts (apache) or possibly some other form of > server side scripting (php, mod-perl, mod-python) would allow URLs > somethin like: > > http://localhost/cgi-bin/pic-wacker?port=com1?func=analog?chan=1 I guess this is as good as it gets. Inventing a new protocol doesn't make much sense, because none of the browsers would understand it -- and that's the start idea of this, if I understand it correctly. What good does you do a com1: or ser: or serial: protocol if you have to write your own browser to use it? So stick with http (that's what you seem to want to use anyway, indicated by your wanting to use GET and POST, both http commands), run it to a local web server (enough free ones around, including IIS) and provide a program there (ASP, PHP, Python, whatever) that performs the serial communication, in a form very similar to how it would talk to a database. It seems this guy has done just this (from Richard's post): http://www.easyvitools.com/ezcom2web/index.html The thing left to do is to come up with a serial protocol that addresses all your needs and that you implement in a language of your choice on the PC as a cgi program or script (so that it can run under control of the local web server). Gerhard