Hello Everyone,
I have this MCU which has a DB-9 terminal... I would like to
change that DB-9 to a USB port, what all changes would I need to
go through?

Should I just connect a 47Ω resistor in series with the Tx and Rx ports of the RS-232???

 

Hello,

RS232 and USB are totaly diffrent.
http://www.educypedia.be/computer/rs232485.htm
http://www.educypedia.be/computer/pchardwareportsusb.htm

There are RS232 to USB converters available, here is an example:
The economy version:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=768-1014-ND
And the full version:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=768-1013-ND

Bertus

 

Hello,

RS232 and USB are totaly diffrent.
http://www.educypedia.be/computer/rs232485.htm
http://www.educypedia.be/computer/pchardwareportsusb.htm

There are RS232 to USB converters available, here is an example:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=768-1014-ND

Bertus

Sir, thank you very much for the answer, I know about the cable, but I
want to avoid cables... all i need is simply a USB port hooked on the output of the MCU, so that user can put in his memory stick and gather data... rather than connecting through a DB-9 port...

 

Hello,

If you want to connect a usb memory stick to the MCU, the MCU needs to be a host for USB.
That will take probably an other MCU than you are using now.
Read about USB in the links on the page I provided.

Bertus

 

Hello,

If you want to connect a usb memory stick to the MCU, the MCU needs to be a host for USB.
That will take probably an other MCU than you are using now.
Read about USB in the links on the page I provided.

Bertus

hmm... alrite, thats what i thought so, isnt there a simple way apart from this???

 

Hello everyone,
I was doing some research on the available chips that can be used for rs-232 to USB conversion as it would be a matter of everyones concern to use such a chip... and i found some links..

Please go through it and let me know if these chips can be used with min coding to convert from UART - USB
http://www.silabs.com/products/interface/usbtouart/Pages/default.aspx#Matrix
http://focus.ti.com/lit/ds/symlink/tusb3410.pdf
http://www.futurlec.com/RS232_Converter.shtml
http://www.linxtechnologies.com/Documents/SDM-USB-QS_Data_Guide.pdf

 

These chips won't help. They are just so you can plug something that is RS232 into an USB socket. The computer and a driver sees the external system much as a normal serial port. The data is still in the RS232 format, it has just gone via the USB protocol and back.

 

well, basically I would like a user to gather data from a USB port instead of a RS-232 terminal...

There is no intelligence required at the USB level.. It would only be used as a mode of gathering data in a Data Acquisition System..

Will it not work in such kind of application?

 

I think the first, 3rd and 4th links would be suitable for that. They won't let you plug a memory stick into the microcontroller, but will allow direct PC-microcontroller communication.

 

CrackJack, USB REQUIRES intelligence, it's not a simple protocol there is no quick and easy hack you can do to make it compatible.

A USB to RS232 adapter can be had for 10-20 dollars. You will find nothing cheaper than that home made or not.

 

I got some extra USB2Serial adaptors I'm selling off for $3 shipped in the US. I've sold a couple already so I'm sure you can find others to tell you its a good deal. They are made by Cables 2 Go
These
http://www.google.com/products/cata...WvOKLWxQXSo42kBw&sa=title&ved=0CDEQ8wIwAzgA#p
There NIB too with antistatic bag and CD. That goes for any members too. I just want $1 + shipping INTL too so if you out of the country just let me know and if you pay the shipping I'll send it. I sent one to retched so he can vouch for it.

 

u'll need to use a converter like FT232 for UART 2 USB conversion