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Dangerous Prototypes

Other projects => Past projects => Breakout boards => Topic started by: charudatt on March 17, 2011, 09:45:22 pm

Title: MCP2200 breakout board RS485 USB bridge
Post by: charudatt on March 17, 2011, 09:45:22 pm
I wish to use this Breakout Board to build a RS485 <> USB bridge and was wondering if I could use the RTS/CTS pin to switch the Rx/Tx pins on the RS485 Chip.

There's some mention of these PIN on at http://http://dangerousprototypes.com/docs/MCP2200_breakout_board but I am not able to follow.

Any suggestion as to how I can go about with the idea.

regards
Charudatt
Title: Re: MCP2200 breakout board
Post by: Sjaak on March 17, 2011, 10:35:11 pm
The rts and cts are controlled locally on the chip instead of on the computer connecting to the mcp2200. This can not for example reset an arduino (the rts is connected to the reset line of the arduino).

AFAIK the rts/cts is used to switch between receiver and sender on rs485 so it is prolly not usable as-is. However with our USB stack you could develop a workable sollution (need a lot programming!!). If you not upto this a ft232 breakout is prolly more suitable for you.
Title: Re: MCP2200 breakout board
Post by: charudatt on March 17, 2011, 10:41:29 pm
Thanks,

In that case, I use the Rx/Tx status LED for switching the RS485 Send/Receive.

I was wondering if I could use the GPIO pins on the chip , without extensive programming.

regards
Charudatt
Title: Re: MCP2200 breakout board
Post by: Sjaak on March 17, 2011, 11:09:07 pm
The GPIO are easily accessable through their driver. They provide a .dll (windows) to easily acces the gpio.

a link to the information of the mcp 2200: http://www.microchip.com/wwwproducts/De ... e=en546923 (http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en546923) and .dll: http://ww1.microchip.com/downloads/en/D ... lities.zip (http://ww1.microchip.com/downloads/en/DeviceDoc/Drivers%20and%20Utilities.zip)

Keep us informed!
Title: Auto Switching, Self Powered USB <> RS485 using MCP2200
Post by: charudatt on May 04, 2011, 12:18:16 am
I have successfully made a Self switching, Self powered USB <> RS485 using the MCP2200 Breakout Board.

I have successfully tested it (@ 9600) and it works

Here are the details.
Title: Re: MCP2200 breakout board RS485 USB bridge
Post by: ian on May 04, 2011, 07:28:35 am
Very cool! Thanks for the update. I'll post it on the blog - is there a link to download the files?
Title: Re: MCP2200 breakout board RS485 USB bridge
Post by: charudatt on May 04, 2011, 07:50:27 am
Later in the day, I can upload them here and then you can make them available , where ever you want them to be.

I also have, a PCB for the RS232 out, but I guess, that's not as important as this one. I would also be posting it here, along with the file.

regards
Title: Re: MCP2200 breakout board RS485 USB bridge
Post by: charudatt on May 04, 2011, 04:18:34 pm
Here are the PCB layout files in Post Script. The zip file also contains Schematic and Overlay for the project.

regards
Title: Re: MCP2200 breakout board RS485 USB bridge
Post by: JanW on May 23, 2011, 12:19:45 am
What's the purpose of the optocoupler?

Regards,

Jan
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