Skip to main content

SIM900A TCP connection test - 1

I have been working on some real time data acquisition and control application designing. Specially micro-controller based hardware designing and prototyping.
For testing purposes i am using SIM900A GSM/GPRS module and FTDI UART converter. 

SIM900A module is connected to PC via FTDI converter. I use putty as a terminal program to communicate with the module. With required baud rates i am able to communicate with the module by sending a simple AT command (AT command set will vary with different modules) just sending AT the module replies with OK. This means module responded to the command sent from PC. Lets go ahead with TCP AT commands to establish a TCP connection to remote server via GPRS connection.


I have run socket test software on remote PC and opened port 7777. You have to check your firewall or router settings to allow your preferred port. While the software start listening to port 7777, lets continue with the sending AT commands to module from the PC connected to module.

After power up the module please wait for a while to give time to connect to GSM network from module and after few seconds lets proceed with TCP.

I have send these few commands manually from the PC which the module is connected.

AT+CIPMUX=0
AT+CIPMODE=0
AT+CGATT?
AT+CSTT="APN of pixelatedpic"
AT+CIICR
AT+CIFSR
AT+CIPSTART="TCP","remote pc/server IP ","your preferred port"
AT+CIPSEND=20 
your data to send and hit ENTER


Here is the data sent between module and sever via GPRS internet. The data transmission of both directions is successful. Next is try to send the AT commands from Arduino instead of doing manually.

I love to see more comments from the viewers.
stay tune for part 2.
Post a Comment

Popular posts from this blog

SIMCOM SIM900A fixed

Since everyone is interested in this post and lots of request comes to get the firmware, i have put a link so that everyone can download it easily. SIMCOM 900A firmware

Its been a while that i was trying to fix the SIM900A GSM module. This module support local GSM band but after some researches it was concluded that it is carrier locked :(. After long conversion of days to actual chip manufacture SIMCOM, they told it can be fixed by updating its firmware to latest original version but unfortunately they don't provide firmware to small parties.

I never stop trying to get the firmware and SIMCOM again replied, this time they said contact local SIMCOM supplier and request for firmware. But this little Maldives don't have SIMCOM or any electronics manufacturer. So i contacted my friend coody from NOA LABS/Smart prototyping (a friend in china) and told him to help me. I explained him what to do so he can communicate with SIMCOM in china.

Finally he sends and email saying that he g…

Clover Display M302 hack

Its been a while i have this LCD and today i thought of connecting the LCD display to Arduino. Unfortunately i could not found any pin outs of this from any where and from the manufacture. Actually this is very old model which i got from old FAX machine and this display is a very cheap from online sources.
Clover Display M302 PCB Ver 1.0 (16x2) which has 10 pin flat cable. After researching for a while from the internet i have seen in many forums people are asking for help on how to connect it and what is the pin configurations? so i thought of helping them as well as my self at the same time.
After going through some of my old collections of Russian data of displays and things i found a basic diagram of how 10 pin LCD display configuration. 
PIN1   - VSS PIN2   - VDD PIN3   - CONTRAST PIN4   - RS PIN5   - R/W PIN6   - ENABLE PIN7   - DB4 PIN8   - DB5 PIN9   - DB6 PIN10 - DB7
I tried these configurations and wired up to the arduino with the LCD sketch and it worked on the first try. …

ESP8266 + DS18B20 Temperature sensor sends data to Thingspeak.com

Its been a while i was searching for a cheap wifi module and with the help of smart-prototyping.com, i was able to get a module almost less than USD 5.


To connect the module to breadboard for prototyping, i made a small jig to interconnect with the board easily. So i can wire up the device and interface anything to GPIO's.



Be careful with the module cause the device it powered with 3.3V and both UART side levels will be 3.3V so i recommend to use a FTDI converter with 3.3V level select.(one i used can select 3.3 and 5 volts) if you connect 5V the module will fry up. If you have 5V or 12V supply to power up the module i suggest to use LD1117V33 to make 3.3V.

The stock Firmware in the ESP8266 supports AT commands and for communicating with this need an micro-controller like Arduino. But i want to make a simple solution for that without using external micro-controller. NodeMCU firmware was the best thing i found. To upload the NodeMCU firmware please do a google search, there are tons o…