Abstract:

Mobile message printing system using Thermal printing through GSM modem.

In these modern days everything is getting automated, thus reducing the manual and effort and save lot of time. Paying bills for home needs is in manual process which takes lot of time and even there are possibilities for human error. In this project we avoid such manipulations and save time. Instead of written signed paper bills, E writing (printing) is the best option to avoid human errors and saving time.  Here in this project we use thermal printer for printing text data on Thermal paper. We could update data to web server wireless protocols. These web connected applications belong to server client relation. TCP, UDP and HTTP protocols are used in this concept. Data transfer to web server through GPRS (General packet radio services) communication. We can transfer long data through this GPRS. Many Embedded Networking applications fall under this model only.

      In this project we have interfaced a Thermal printer to microcontroller. Thermal printer is a miniature portable printer which prints characters on Thermal paper. In this project we could print different characters and character styles on thermal paper with thermal printer and message (data which we want to print on Thermal paper) coming from a serial interface. This serial data may come from different interfaces like x-bee, GSM modem, GPRS modem… etc., and here we interface GSM modem to microcontroller. Data which we want to print on Thermal paper is send to GSM modem from a mobile .This thermal printer works on ESC/POS commands which is more advanced than dot matrix printer. No need of feeding printing powder or cartridge. We can print any numeric, alphabet or special characters and can specify line number also.                  Here we use 8051 as a microcontroller with 5v DC Power supply.  Serial (UART) protocol is primary concern here. The main heart of this project is GSM/GPRS modem which works on GPRS AT commands. 16X2 LCD is connected to microcontroller through Digital I/O lines. AT keyboard is interface to microcontroller with PS/2 connection. 4X4 keypad is directly connected to microcontroller. Thermal printer connected to microcontroller serially and it works on ESC/POS commands, but microcontroller has only one serial port so that we have to use serial shift driver (built with relays or driver ics – depends on availability and possibility).

TECHNICAL SPECIFICATIONS:

HARDWARE SPECIFICATIONS

Micro controller         :           AT89x series

Crystal                        :           11.0592 MHz

LCD                            :           HD44780

LED                            :           5mm Red LED

Printer                         :           Thermal printer (miniature)

Serial shifter               :           CD4016

Basic GPIOs

GSM/GPRS modem   :           Sim300/ Sim 900

RS232 interface          :           ST/MAX: 232

POWER SUPPLY

Transformer                :           12V step down 

Filter                           :           1000uf/25V

Voltage Regulator      :           7805 / 7812

SOFTWARE SPECIFICATIONS

Software tools used

Keil IDE

Proteus VSM

UC flash

APPLICATIONS

• Electrical department
• Power plants
• Domestic        
• Industrial
• commercial