View Full Version : Read SD card on computer through Teensy 3.0

12-04-2012, 07:50 PM
I have data on an SD card. The connection between the SD card, teensy, and computer is about as follows:

SD card <--> Teensy 3.0 <--> Computer

I want the computer to be able to get data from the SD card THROUGH the Teensy 3.0. Am I limited to using something like serial.print with the low bitrates like 115200bps? I know that the Teensy itself can communicate quite quickly with the SD card thanks to a certain library which Paul linked to in an update some time ago. See http://arduino.cc/forum/index.php/topic,128335.msg965170.html

12-04-2012, 11:11 PM
You don't specify the nature of the Teensy 3 <--> Computer connection, but if you are doing the simplest thing (using the T3's USB connector) then it always runs at the 12 Mbps ("USB full speed") datarate, not 115200 bps or whatever you set in the Serial.begin() statement. That bitrate number is only relevant if you're using one of the three UARTs (eg Serial1, Serial2, Serial3) which requires additional wiring to hook up to a genuine RS-232 port, or a USB port on your computer.

12-05-2012, 04:06 PM
Oh, the Teensy 3 is connected via USB to the computer. The SD card is connected to the Teensy via SPI. I suppose my question is: If I use something like serial.print to dump the files from the SD card to the computer, will it be limited to 115200bps or will it be limited to 12Mbps?

Based on what you said, it seems like it'll be at 12Mbps, but I'm not sure and so I wanted to check.