1. Introduction of GSM/GPRS ATC-E05
ATC-E05 Easy is a product designed by AT-COM to provide users with integrated facilities that are interconnected into a network through ATCBus.
The power of the board is expressed through the Ublox G340 module with features of GSM, GPRS.
The G340 muodule is the latest 2G series, delivering optimum performance in SMS, data and voice communications even in harsh environments. The ATC-E05 is full of features to provide you with ideas for wireless-based applications
2. Schematic of ATC-E05
3. Feature of GSM/GPRS ATCE-05
a. Module ATC-E05
The G340 integrates 2G's advanced technologies into ATCE-E05 module. The ATCE-E05 module is product line with dual-band GSM and GPRS capabilities and can connected to the Ublox GNSS module via the SCL and SDA pins of the ATC-BUS
The ATCBus Socket with integrated pins allows users to connect to products that support ATCBus easily. All in one ATCBus.
b. Power supply and ON/OFF module Sara G350
The SARA-G340 module has to be powered by a clean and stable power supply. Power supply for ATC-E05 Easy via ATCBus at two pins 5V and GND. The 5V main power will be converted to 4V and supply for SARA G340 module. This power provides up to 1.6 Amps and drop voltage when the load does not exceed 400mV.
Although the SARA-G340 is a low power device, the cellular network modules in general, are notorious for their high power consumption, so the 1A LDO had to be used
Some main feature of power IC RT9048:
Default module Sara G340 can swiched on after supply 5V@2A power at pin 5V of ATC-E05
The circuit is designed with a transistor turns on/off Sara G340 module. It is possible to power on/off Sara G340 module in two Methods:
- Method 1: Use the On / Off button on the circuit.
- Method 2: Provide a high-level pulse for at lest o one second to the PWR pins of the ATCBus Socket, the Sara G340 module will be powered on
- Method 3: Use AT+CPWROFF command to on module
c. Logic voltage selection
To communicate with external devices with logic 5V/3V, the board has a custom designed user interface with 3.3V/5V logic voltage for application. When manufacturing, the default logic voltage is 3.3V logic level
ATCE-05 use bidirection logic translator TXB0106PWR of Texas Instruments, it can use to convert logic level from 1.2~3.6V to 1.65~5.5V and bidirection with speed up to 100Mbps. Logic level communicate of Sara G340 is 1.8V and level logic of microcontroler nomal is 3.3V/5V, so voltage translator IC need to use to compatible signal level.
ATCE-05 support UART interface to communicate with Sara G340 module via AT command. UART interface supports baud rates from 2400 bps to 9600 bps and automatic baud rate detection for up to 115.2 kbps. The automatic baud rate detection mode is set by default
At default mode, Sara G340 can’t communicate with external device via UART interface. So to enable this function need to pull up WKP pin of ATC-E05 to high level.
How to change the communication voltage:
- Remove the 0R resistor (size 0603) at the unwanted position.
- Solder the 0R resistor (size 0603) to the desired position of 3.3V or 5V.
d. Audio and MIC port
The SARA-G340 module offers extensive audio features, including Half rate, full rate, enhanced full rate and adaptive multi-rate voice codecs, superior echo cancellation and noise reduction, multiple pre-programmed audio profiles, specialized hands-free algorithm, all configurable with the AT commands. The audio DSP section is integrated inside the module and it requires only a few external components. The headset can be connected via the 4-pole 3.5mm audio jack. With ATCE-05 user can use this application audio via the 4-pole 3.5mm audio jack.
e. Antenna GSM
Module Sara G340 support for Europe/Asia dual band 900/1800 Mhz and data rate up to 85.7kbit/s. Module has 50 Ohm smd antena pad, with this function user can add some components to make own GSM/GPRS application.
With the design of the ATC-E05 supports 2 type Antenna GSM are through hole connector and SMD connector for users can choose the antenna type for their applications.