Maximum Speed of Hardware Serial. FTDI FT232R Chip

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I've got a project where I'm pumping data from MaxMSP in to an arduino.

Currently I'm at 115,200 and given the code I'm using on the Arduino, I'm able to get about 9KB/second into the Arduino without dropping data. (I'm assuming that as I push more data from MaxMSP, I'm overflowing the FT232R at 115,200 buad.)

I looked up the data sheet for the FT2323R chip, and it seems like it's capable of going up to 1Mbaud, so I experimented with some alternative baud rates higher than 115,200 but nothing worked.

Is it possible to send data into the Arduino Duemilanove at higher than 115,200 using the built in USB (FTDI FT232R) connection?

I'm fairly new at Arduino, so I apologize in advance if this seems like an obvious question.

2

Ping.

Anybody know if the on board hardware serial connection can be pushed to greater than 115 Kbit?

If so, how?

3

Compress the data before sending...
Just shooting from the hip here... :stuck_out_tongue:

D.

4

Data is already compressed. At this point I need to push as much data as possible to the arduino. In the 500 to 1000kbit range.

In searching around, I've come across the "teensy" which can operate at much higher data rates because the USB signal isn't first converted to serial. Might give that a shot.

http://www.pjrc.com/teensy/td_serial.html

5

I remember a post a (long) while back, where someone tweaked the code Arduino is based on and achieved much higher serial speeds.

But i can't find the post right now.

try to use google to search the forum.

6

I've had good luck with the Teensy. A few observations...

  • Supposedly, the data rate is 12Mps. I believe it. The baud rate is actually ignored.
  • It's my understanding that the USB chip provides send and receive buffering.
7

It's mentioned here...

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1235580746
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1254424833

8

Thanks guys.

I might give Teensy a try. I need to check to see how MaxMSP communicates with the outside world. Hopefully there's not a limit on that end. (MaxMSP on Max OS X). Ultimately, I'm building something that will take a output from MaxMSP and use the Arduino to display it. Currently I've got it working driving 1536 LEDs but want to pump it up to 2 to 4 times as many pixels and am currently being limited by the 115,200 baud rate.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1225239439/169#169

@Coding Badly: Thanks for the links. They are very helpful.

9

I also remember some posts a while back where people were complaining about MAX being slow to communicate over serial.

So maybe you should set up some kind of test to determine if MAX or Arduino is the bottleneck, before you do something else.