Transmit file from Arduino to SD card of 3G shield

hitman713 · **Joined:** Tue Jul 03, 2012 7:12 am **Posts:** 9

Hi, is there any way to transmit file from the SD of Arduino to the SD card of the 3G shield, then transmit the file? Thanks in advance.

libelium-dev · **Joined:** Mon Sep 28, 2009 11:06 am **Posts:** 2041

HI hitman713,

The SD card of the 3G shield is not accesible from the SPI pins. If you want to write in the SD of the 3G you should use the Xmodem protocol.

Regards.

hitman713 · **Joined:** Tue Jul 03, 2012 7:12 am **Posts:** 9

Thanks for the reply, so is there any other way for me to write a file from the Arduino board to the SD card in the 3G shield?

And also can you guide me to better understand the xmodem protocol?

libelium-dev · **Joined:** Mon Sep 28, 2009 11:06 am **Posts:** 2041

Hi hitman713,

XMODEM is a file transfer protocol. The link below have the complete manual and the File Transmission Related Commands.

http://www.cooking-hacks.com/skin/front ... manual.pdf

Best regards.

hitman713 · **Joined:** Tue Jul 03, 2012 7:12 am **Posts:** 9

My main concern is to save a file into the SD card of the 3G shield using arduino, so is there any solution, hardware or software?

libelium-dev · **Joined:** Mon Sep 28, 2009 11:06 am **Posts:** 2041

Hello hitman713,

You can use this modulo to save a file into a SD.

http://www.cooking-hacks.com/index.php/ ... duino.html

Regards.

hitman713 · **Joined:** Tue Jul 03, 2012 7:12 am **Posts:** 9

I have the modulo to work with, it juz that i want to create a file using Arduino and then send it out through FTP, but in order for the module to send the file out, it needs to be in the SD card of the 3G module, i need a way to put that file inside the SD cardof the 3G module.

libelium-dev · **Joined:** Mon Sep 28, 2009 11:06 am **Posts:** 2041

HI hitman13,

The section 15 of the manual (15 File Transmission Related Commands) shows you how to transmit files to the SD of the module using the XMODEM protocol.

http://www.cooking-hacks.com/skin/front ... manual.pdf

Regards.

hitman713 · **Joined:** Tue Jul 03, 2012 7:12 am **Posts:** 9

Hi, i read through xmodem protocol and the AT command guide, it seems that in order for the 3G shield to receive the data, it must first send a <NAK> to signal it is ready to transfer, how do i trigger that? Thanks.

libelium-dev · **Joined:** Mon Sep 28, 2009 11:06 am **Posts:** 2041

Hi hitman713,

If the receiver did not receive a valid packet it sent a <NAK>. It means that there was a problem in the communication.

Regards