Author Topic: USB to RS485 Converter and General Purpose IO  (Read 2897 times)

marv2097

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USB to RS485 Converter and General Purpose IO
« on: April 04, 2008, 01:00:30 pm »
Hi all,

In my spare time I have been working on a number of different hardware devices that I plan to use with with LMCE and ZM amongst other things. They are still very much in the prototype phase but if anyone is interested in trying these out with LMCE then please get in touch. Any feedback good or bad would be greatly appreciated.

USB to RS485

The first of these is a USB to RS485 converter based on FTDI 232RL chip. At present it hasn't been tested on Linux or LMCE but is working fine in Windows. Drivers are freely available for Linux so I assume it would work fine in LMCE. I am currently using these to control speed domes and it works well as an alternative to the RS232 to 485 converters. As my machine has a lack of normal serial ports I can put a few of these on a hub and have as many RS485 buses as I want.

Here is what the PCB looks like, there is a jumper to allow it to be 120R terminated and another header to tap of the logic TX, RX and R/W. There are also 4 LEDs to show Power, Sleep, TX and RX activity.



It is designed to be fitted into a DIN rail mounting which is ideal for a permanent installation. It has some mounting holes so I guess it could be used in other enclosures or inside a PC casing too. At the moment there are no holes in the case for the leds but there will be some added soon.



General Purpose IO Board

This prototype IO board can control 4 10amp 250V relays or 4 opto isolated inputs. Or any combination of the two. It is controlled by RS485 and can use a supply voltage between about 7v to 25v AC or DC. I have written some basic firmware which responds to Pelco commands so it could be used to control something like a pan/tilt head etc. With the correct firmware it could be used to do many different things such as Lighting control, Sensor monitoring, Gate control etc etc.



I have a couple of other things in the pipeline such as RFID readers, Temp monitors so if anyone has any interest in expanding LMCE to do more, than I would be interested to hear your views and opinions.

//Marv
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hari

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Re: USB to RS485 Converter and General Purpose IO
« Reply #1 on: April 04, 2008, 11:00:53 pm »
wow.. I'm very impressed ;)

when you have problems controlling the stuff just visit the developers forum,

best regards,
Hari
rock your home - http://www.agocontrol.com home automation