- 4G LTE Cat1, DC-HSPA+
- Fallback to 2G capabilities: Bands Support: B3/B8
- GNSS: GPS/GLONASS/BeiDou/Galileo and QZSS
- Support IPX antenna connector for GNSS and 4G
- Support micro USB 2.0: user can communicate with EC21 module via AT command, get NMEA data of GNSS, software debug, upgrade firmware
- integrated button power on/off

1.Introduction about LTE/3G/2G Quectel EC21

ATC-E09 Easy board is a designed by AT-COM to provide users with integrated facilities that are interconnected into a network through ATCBus.

The EC21 module is the latest 4G/2G series, delivering optimum performance in SMS, data and voice communications even in harsh environments. The ATC-E09 is full of features to provide you with ideas for wireless-based applications. In addition, ATC-E09 is integrated ability received GNSS signal from satellites: GPS, GLONASS, Beidou, Galileo and QZSS. So, ATC-E09 supplies full features to make wireless connection applications.

2. Schematic

3. Features of 4G Quectel EC21

a. Module ATC-E09

The EC21 is integrated 4G's advanced technologies of Quectel and have been embedded into ATC-E09 module. The EC21 module is product line with 4G technology and fallback to 2G capabilities. In addition, EC21 module has integrated GNSS machine and ability receive signal from satellites: GPS, GLONASS, Beidou, Galileo and QZSS.

Some feature of EC21 module:

Product is integrated ATCBus Socket with sequential arranged pins in order to users can easily connect to other products that support ATCbus. All in just one ATCBus.

b. Power supply and control LTE EC21 module

EC21 module need a clearly and stable power supply in order to module can stable operation. The power supply for ATC-E09 module through 5V pin (pin 11 of ATCBus) and GND pin (pin 10 of ATCBus) of ATCBus. This power will be drive to TJ4320GDP-ADJ of  HTC Korea and be converted to 4.0V for EC21 module of Quectel.

The LDO TJ4320GDP-ADJ has high ability and can create 4V power output with current up to 2A and drop volt doesn’t exceed 400mV when no load.

Although the EC21 is a low power device but it needs a lot of power to power on and drive modules inside of EC21 stable operation. So TJ4320GDP-ADJ is suitable for this application.

Some main futures of LDO TJ4320GDP-ADJ:

ATC-E09 have functions to enable turn on and turn off module EC21. So, user can use functions in three methods:

• Method 1: Press the PW_KEY button and release this state about 2s. After module is already power on, LTS led will be on. When module in the power on state, user can turn off module with step by step same above way.

• Method 2: Make a high logic to PWR pin of ATCBus and release this state about 2s. After that, turn logic voltage level at this pin to low logic or default state. Observe the status of LTS led on board, when module EC21 is powered on success, led LTS will be on.

• Method 3: After module EC21 in the operation state, user can use at command AT+CPWROFF to power off this module.

c. Select communication logic voltage level

To compatible voltage level with external device, ATC-E09 have a function to enable adjust voltage level between 3.3V and 5V to compatible with voltage level of user applications. Default voltage level on ATC-E09 is selected 5V.

ATC-E09 uses bidirectional logic translator TXB0106PWR of Texas Instruments which can use to convert logic level from 1.2~3.6V to 1.65~5.5V and bidirectional with speed up to 100Mbps. Logic voltage level of Quectel’s EC21 is 1.8V and equal to level voltage of VDD_EXT pin of Quectel’s EC21 module. So, Logic voltage convert IC need to be use to convert logic voltage level to 3.3V/5V in order to protect EC21 or external device and help communication between EC21 and external device is more stable.

ATC-E09 have a UART interface allow external device communicate with Quectel’s EC21 module by AT command. Through TX and RX pins on ATC-E09, user can communicate, transfer and receive data to 4G/GSM network or can require GNSS data from EC21 via this interface. Quectel’s EC21 module supports baud rate for communication from 9600 bps to 3000000 bps and default baud rate is 115200 bps.

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Method to switch communication logic voltage level on ATC-E09:

• Remove 0R resistor (0805 size) at current location (default is 5V location)
• Solder this resistor to beside location on board.                                 

 d. Antenna 4G/UTMS/GSM/GNSS for EC21

Quectel’s EC21 module can operate on 4G/UTMS/GSM of EU network and Asia network with 4G bands are 850/900/1900/900/2100Mhz and 2G bands are GSM 850/1900 and 900/1800 MH. Speed for DL and UL data at 4G mode up to 10 Mbit/s and speed at 2G mode up to 296kbit/s. EC21 Module have three pads antenna allow connecting to external antenna via antenna connectors to run applications DL and UL data on 4G/UTMS/GSM network.

ATC-E09 have three IPX antenna connectors include: Main and div antenna connector for 4G/2G network and GNSS module. So, user can use external antenna 2G/4G/GNSS to connect to antenna connectors and make own applications.

In addition, EC21 module have ability getting GNSS signal from satellites: GPS/GLONASS/ BeiDou/ Galileo/ QZSS. So, ATC-E09 is integrated smd ipx connector on board to allow connecting to external GNSS antenna to get GNSS signal.

e. LED status indicator

3. USB

ATC-E09 is integrated micro usb 2.0 connector of Molex and support speed up to 480Mbps. Through USB interface, user can communicate with EC21 module via AT command, get NMEA data of GNSS, software debug, upgrade firmware.

4.Sim Card connector

ATC-E09 module is designed with a micro simcard connector on board, allow insert external micro simcard to this connector to EC21 attach to 2G/4G network and can make applications transfer and receive data to cloud or server.

5. Dimension

6. Video