Hello,

I've recently bought an Arduino Uno & a SIM900 (http://www.cooking-hacks.com/gprs-quadb ... or-arduino). In the SIM900 i have placed a new (activated) sim card and an antenna (http://www.cooking-hacks.com/internal-4 ... sm-antenna).

The jumpers are in the following position:
https://drive.google.com/file/d/0B8o-1z ... sp=sharing

Ive tried the first code of step 5, sending a text message, but nothing is working: http://www.cooking-hacks.com/documentat ... and-sim900




Can anybody help me, or tell me what I am doing wrong?

Hi mick,

When you upload a sketch to your Arduino, you need to put the jumpers in ARD position.

Regards.

Hello,

Is it possible to help me out more?
Is it required to have an external adapter (I do have this, if this is needed).

Without an external adapter I need to set the EXT to "Arduino 5V", with an Adapter I need to put it on "V ext".

For uploading the sketches I need to put the serial jumpers on "Arduino" mode. But nothing is happening.
If I put the jumpers on "USB Gateway" it still isn't working.

Any tips or help!?

Extra notation:

I now have the following setup:
- No external adapter (only usb)
- V in Ext to Arduino 5v
- Serial com jumpers to USB Gateway

In the serial monitor I am typing this:
- AT // the response is OK
- AT+CMGF=1 // the response is OK
- AT+CMGS="+316xxxxxxxx" // It now is possible to typ an message
- After that, nothing is happening.

Hi mick,



Yes, you need to use an external power supply.



No, you have to use always "Arduino 5V", you will only use "V ext" if you connect the external power to the GPRS.



To upload a sketch you need to put the jumper in "USB" then, to run the code, you need to put the jumpers in ARD.


Regards

Thanks for the help. This worked a lot, and got more response out of the Arduino.

I still get a error. Maybe you know why.




The error outputted on the serial monitor is the last 'error' one in the script.

Hi mick,

Can you try with:

answer = sendATcommand("", "OK", 40000);??

Regards.

Hmm.. this shutted my Macbook down (purple screen!)

Other question: I also checked out similar problems.

I use the Arduino EDE. In the serial monitor I put the following commands:

AT
AT+CSCA?
AT+CMGF=1
AT+CMGS="*********"
> Here I write a message (without CR / LF)


But how do I send it? : CTRL+Z / 0x1A (hex input)
The Arduino EDE doenst have a hex input.

Hi mick,

You can't send hex in the Arudino IDE, you need to use other serial monitor like CUTECOM.

Try and tell us.

Regards