Hey Guys,
I hope this post is in the right forum.
I am doing a basic UART TTL to RS232 communication. I have ordered the converter Mikroe Max232 Board.
But is it true that I can not use a usb to rs232 cable adapter. such as the one below because those come with drivers used by Windows/Mac.
Thx
I don't see why not.
In some products I have the MAX3232 installed and i'm communicating with it with several usb-RS232 cables.
Only thing is: The max232 works off of 5V. So if your atmel has a TTL level voltage of 3.3V it won't work all the time.
It's better to use a MAX3232 for it works with TTL 5V and TTL 3.3V. Altough it might work for your setup.
A cable is just a means to connect stuff. What is that usb socket attached to? If it's attached to your uart, no problem, but if it's connected to the USB port on a computer, you're doomed to failure.
According to what you have posted, you propose to use a ridiculously expensive USB to RS-232 cord, having cited a website which explains that it is obsolete and is replaced by a marginally cheaper one (which is certified for Windoze 8, and feed it into a RS-232 to TTL converter.
Why?
Are you aware that the USB to RS-232 cord internally consists of two chips, a USB to TTL converter plus a TTL to RS-232 converter? So you would be converting USB to TTL, TTL to RS-232, RS-232 back to TTL?
Would you not prefer to simply use the USB to TTL converter itself and connect that to your TTL (actually, CMOS) level circuitry? They are available quite cheaply - if you are careful to avoid anything advertised as using an "FT232" chip. 
Now when you say "is it true that I can not use a USB to rs232 cable adapter ... because those come with drivers used by Windows/Mac", are you suggesting that you do not wish to use Windoze or Mac? If you are using current Linux (such as Mint), then virtually all such interface chips will function with no problem - because that is just how Linux works.
I use simple USB -> TTL cables like these Gefen (EXT-RS232) RS-232 Cable for sale online | eBay . I primarily use them with Linux but have used them in a limited way with Windows XP and 7.
For both Linux and Windows no special driver is needed. The primary problem one has with these is working out the device name to access them by. On Linux this may change each time they are plugged in but by using 'udev' one can define an alias (actually a soft link in /dev) so that one can fix the device name (as long as they are plugged in the same USB port each time).
Since they are just two wire type devices, one needs to use software handshaking if handshaking is required.
The biggest drawback I have found is the 3+ week delivery but they are so cheap that I now keep a stock of about 5 and re- order when I get down to just 1 left.
Why not buy locally then?
I use FTDI boards from www.tinyosshop.com for offboard USB needs, they arrive quick and only need a USB-A to USB-B Micro cable.
For onboard use, I solder in a MIKROE-483 from www.mouser.com.
Examples:
CrossRoads:
Why not buy locally then?
I use FTDI boards from www.tinyosshop.com for offboard USB needs, they arrive quick and only need a USB-A to USB-B Micro cable.
For onboard use, I solder in a MIKROE-483 from www.mouser.com.
Examples:
Is the FTDI thing over now?
Wouldn't want to "buy cheap" if things are unsure (not a comment on the device you linked).
Apparently over.
Both of my sources are using genuine parts.
CrossRoads:
Why not buy locally then?
Dramatic priced difference! I can buy at least 5 from China for the price of 1 in the UK. If anyone can provide a local source with comparable price then I would like to hear from them.
The problem with FTDI chips from China is there is no way of telling they are genuine till you plug them into a Windows box. On the other hand you can buy CH340 USB to serial for small money, with quick delivery from the UK.
