RS485 to picaxe

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HAZELEB

Member
Hi, I have a four camera DVR card on my PC and it has pan/tilt capability, Pan/tilt cameras are very expensive so I have built my own with two servos and a picaxe its connected to the DVR and I can control it with two push switches and it works ok, however it would nice to be able to control it with the DVR software, so my question is can I? Bering in mind I haven’t a clue about this side of things, in the software you can select the comport, the device address is RS485 protocols are null / linlin / minking / neon / pelcoD / pelcoP / star / vido and visca, If it is possible how?

Any help appreciated

Ted.
 
M

manuka

Senior Member
-device address is RS485 protocols are null / linlin / minking / neon / pelcoD / pelcoP / star / vido and visca
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pelcoD? neon? You really need to tell us more about what these commands do! What sort of camera(s) are you using? What is the software? How far away are they from the controller? What budget?

RS485 is essentially a longer distance (~1km), faster & multi drop enhancement of classic RS232.See here for serial standard specifics. The different RS485 voltage swings & impedance may be PICAXEable if slow baud rates can be matched- I've never considered it before!

Normally a level converter is needed (typically US$30-$40), or perhaps just breadboard up using classic MAX483 or SN75176 etc RS485 driver ICs. Maxim offer a nifty MAX3162 RS-232/RS-485/422 Multiprotocol Transceiver - they even have free samples! Stan.
 
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H

HAZELEB

Member
Hi Stan, Thank you for your reply, As for the protocols in the list I have no clue I have tried to read up on the rs485 and the protocols but it is all beyond me, Three of the cameras are in bird boxes the pan and tilt surveys the garden all cameras are wired direct to the dvr card, the picaxe board controlling the pan and tilt camera is sat next to the computer, the Swann dvr card your name sake is here http://www.swannsecurity.com/s/products/view/?product=379 I’m a retired gardener with no technical knowledge however greatly enjoy tinkering with picaxe but I can not coup with to complicated things and as I have it working with the two push buttons will probably stick with as it is unless a uncomplicated solution is out there.

Regard,

Ted.
 
H

HAZELEB

Member
Hello Hooter, That is very interesting I will work my way though it and let you know how I get on many thanks.

Ted.

edit.
Had a quick look and this could take me quit some time but I will be back thanks.
 
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hippy

hippy

Ex-Staff (retired)
HAZELEB said:
Bering in mind I haven’t a clue about this side of things, in the software you can select the comport, the device address is RS485 protocols are null / linlin / minking / neon / pelcoD / pelcoP / star / vido and visca, If it is possible how?
Click to expand...
Electrical interfacing likely won't be a problem and we can set that aside for now. The important thing is matching the PICAXE receiver to what the PC sends out, which 'protocol' is selected.

Pelco protocols have been discussed before but I'm not familiar with the other choices. Some may be easier for the PICAXE to handle than others. Assuming all will work reliably, there's no major obstacles we're not told about ( data has to pass through an XBee, via a satellite link,back to a 433MHz receiver via an IR link ), I'd choose the simplest which does the job.

The best course is probably for you to do a bit of Googling or Binging to find links to each of the protocols which define what they send out ( and importantly, if anything needs to be sent back ). With those links provided it should be a simple case of people following those links and suggesting which is easiest to use and giving recommendations. I think "linlin" may actually be "lilin".

Alternative just choose a protocol and use that. Ideally one which says, "Go to this position" and nothing more is probably best. That may turn out to be PelcoD or PelcoP.
 
H

HAZELEB

Member
Success

Hi all,
Success using sertxd and serin connected to the comport of the software the lilin protocol gave a unique number for up/down/left/right /stop, so it’s just a matter of using an if statement to compare and jump to the appropriate pan and tilt code, I just never though it could be so simple.
My appreciation to all.

Kind regards.

Ted.
 
M

manuka

Senior Member
Bravo! Just for the record it may be worth you detailing this success story. Perhaps something in the style of an Instructable? Otherwise the same question will no doubt arise again...
 
M

MPep

Senior Member
Further to what Manuka has said, if all else fails, please post in the Finished Projects part of the forum for easier future reference for others. Well done for working it out. :)
 
H

HAZELEB

Member
Hi Mpep, Just to let you know I will post my modest efforts in the finished projects but at the moment am modifying the hardware from the servos to stepper motors in the hope the panning will be smoother.

Regards,

Ted.
 
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