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SIM300 very low speed to upload image

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Newbie level 4
Oct 5, 2009
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Hi Every One who expert on GPRS Module,

I tried to send my jpeg file from USB camera
I test image pic size ~8kb and upload to web server
the GPRS Module spend around 45second I saw my controller
waiting the simbol '>' and 'SEND OK' from gprs on each packet
around >2 second , How can i set the speed of GPRS Module
I saw coding scheme on each CS1.. but I don't know what's it?

this i my connection to gprs
tx,rx , cts ,rts uart speed 57600bps

Thanks for your share some infomation..


Hi Somchock,

You have to change your UART baud rate to 115200bps.

did you use transparent mode in SIM300 for uploading your image?

Thanks for advise ,
I choose another module , Sagem NC
It took around 2 second.


Thank you very much,

Btw, what kind of SAGEM NC did you use?
HiLo - GSM/GPRS M2M Module With Integrated TCP/IP or
HiLo NC - Surface Mount GSM/GPRS M2M Module With Integrated TCP/IP?

thanks for advice.

Added after 23 minutes:

I have a problem with my sim300.
it can get a respons from google, but no respons from my web server.
so i cannot send my image to my web server.

i write this HTTP POST Request in AT command with sim300:


> POST /---/---/upload.php HTTP/1.0^m^j
Content-Type: multipart/fom-data; boundary=123456^m^j
Content-Length: xxx^m^j
Content-Disposition: from-data; name="uploadedfile"; filename="img.jpeg"^m^j
Content-Type: image/jpg^m^j
<image data>^m^j

Can you help me please?
Best regard,

I use HiLo NC.

Have you wrote exactly size of Content-Length (jpg file size+ post data size)
at xxx of http post header Content-Length ?

the webserver will respons back when it received all of data len or will wait packets if is not finish receipt.


Thank Somchok,

yes i have, i count the length of the body request (from --boundary to --boundary--)

do you use a php code to GET the image?
i use: $img = $_GET['uploafedfile'];
in my web server, but SIM300 still cannot send the image.

Best regard,

Hi K.somchok,
I am in thailand too.
I saw you in the topic of grps solution.
My project is using this too,i am using Sim300cz module.
Pls. give me the AT command of sending image via gprs
at j_phetchuen (at) yahoo dot com

and do you know how to connect gprs to gprs as realtime?
i want to sending ascii code between 2 station (same the chat room)
if you know information pls. give me at the same email. na krab

thank you verymuch and nice to meet you.

Hi Hendrik,
pls see on php help about $_FILES["your parameter name"] to get file from uploading.

sawadee krub k' j_phetchuen,
yes ,you can if you don't worry about the cost for gprs connection,
you can set your gprs device as listening (sever) for connection incomming.
I do not much know for this because i have only done code on client side.
The AT command to send data to server pls use AT+CIPSEND
and pls use AT+CSTT for initial connection first.


Thank You Somchok,

i've tried to use POST command in HTTP (port 80), than it doesn't work.
now i use FTP (port 21) to send file but, my sim300 doesn't support multiplex for passive mode in FTP transfer

in my at-command should be:


//and send each of these command below one by one using "at+cipsend=0":
user xxx
pass yyy
type a
stor test.txt


> --this is my data--

my SIM300 revision is 1008B14SIM508M32_SPANSION
now i try to find how to use FTP without using "pasv" for multiplex.

Thank You for your suggestions,

Hi Somchok,

i bought sagem hilo nc three weeks ago.
and i have a problem with building an eval board.
when i type "AT" in my hyper terminal i get only "AT", there is no response "OK" from hilo nc. That also when i type another characters such 1234abcd....etc
i have set the baud rate at 115200.

can you help me with hilo nc Schematic?
i attach my schematic in this post..
Best Regards,


now i can use my sagem hilo now.
but i still got a problem with getting an IP public dynamic from my APN.
i still cannot find the substitution for CIICR anf CIFSR in sim300 for hilo..

can some body help me with getting an IP with sagem?
Best Regard.

Added after 2 hours 25 minutes:

now i can get dynamic public IP, with atctive my PDP content.

and i still cannot connect to ftp server



can anyone help me?
Best Regard,

Hello, nice to meet you all here.

Hendrik, I believe we are using the same schematic. You mentioned you had a problem communicating, receiving an "OK" after the "AT" is sent. I had my
Sagem NC board communicating fine, and sending SMS, etc.. everything great. But
now the communication seems to have locked up. I mean, I send just "AT" and get nothing back. I hooked a LA up between the MAX3232 and the Sagem, and the TX data from the PC is getting to the Sagem, and the Sagem is sending CTS active (low voltage some of the time). But, there is no RXD coming back out of the Sagem to respond with "OK"... very strange.

I noticed in a Hilo NC app not it says...

"Current re-injection appears when the module is off or not powered and I/Os connected to the module still
powered. Example: UART bus powered from the DTE side before the module is powered. This can result in a
bad starting behaviour.

To avoid current re-injection, simply do not supply the lines connected to the module before the module
switches on. Power up the module first using the Pok_in Line then open the UART lines for the DTE side and
all necessary I/O, this will avoid leakage of current improving the power consumption and avoid any possible
deadlock issue during the power up process."

Is this something that you might have been experiencing? Think I might be seeing the phenomena (deadlock).

In my case I was keeping the serial interface to the PC connected whilst powering up and down with a lab supply.. just can't believe that could have caused this issue.

My network "status" LED is blinking away and therefore I believe the module might be alive and well... other than the communication of course :)

Thanks for any help.. since it was working very nicely before, it is doubly annoying that it has just decided to STOP working now :)

-Robert (in Issan)

Added after 42 minutes:

This is also from the HiloNC app note....

" If a Level shifter is used or a RS232 adapter, use the VGPIO signal as the enable signal to avoid any
current re-injection before the module start."

now i can send an image using FTP protocol by SAGEM HILO NC....
i use SAGEM because it can support multiplexing....that SIM300 can't
Thank u 4 all advice before....
i had finished my project....

I want to upload and download a text file from my controller to the remote controller. I am able to connect my server, but can not use ftp commands like LIST, STOR, APPE, etc. It responds with error: 425-Could not open the port xxxx.

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