2G Daughter Board

_images/2G_inst.webp

Description

The GSM/GPRS daughter board adds 2G cellular calling and data capabilities to the WiPhone. Includes: a GSM module – handling calls and texts, a built-in GPRS module – capable of sending data over the cellular network, a nano SIM card slot – for network registration, and an FPC antenna. An audio jack is also installed to connect hands free for voice communication and listening to FM radio stations.

Note

The GSM module requires setup via AT commands and is 2G-only. Service may be discontinued where you live. Check you can get service before buying.

Features

  • Quad-band GSM/GPRS: Supports 850/900/1800/1900MHz frequencies.
  • Supports GPRS multi-slot class 10 for data transfer rates up to 85.6 kbps.
  • Supports GPRS, TCP/IP, and UDP protocols for data transmission.
  • FM radio: Built-in FM radio receiver for audio playback.
  • Low power consumption: Designed for battery-powered applications.
  • 604580 2500mAh Lithium Polymer (Li-Po) Battery

Technical Details

_images/2G_DB_Connector_Pinout_v1.1.png
DB pin# Pin Name Arduino Pin Description
14 3.3V   This pin connects to the VCCB of the TXS0104 logic converter on the daughterboard. Enabling level shifting for WiPhone communication.
2, 11,13 GND   This pin is connected to System GND.
3 TXD_SIM800 38 Connected to SIM800 TX.
4 RXD_SIM800 32 Connected to SIM800 RX.
7 PCM_IN 12 PCM data input.
8 PCM_OUT 13 PCM data output from SIM800.
9 PCM_CLK 27 PCM Clock.
10 PCM_SYNC 14 PCM data frame synchronization signal.
15 RESET EXTENDER_PIN(10) The RESET pin can be used to reset the module. The module can be reset by driving RESET to alow level voltage for time t >105ms.
16 DTR EXTENDER_PIN(11) If the host communicates with module via UART interface, the following preconditions can let the moduleenter into sleep mode.i) Execute AT+CSCLK=1 command to enable sleep mode.ii) Drive DTR to high level.Driving the host DTR to low level will wake up the module.
17 PCM EN EXTENDER_PIN(12) PCM EN pin can be used to Enable or Disable the output state of the TXS0104 logic converter device, enabling or disabling data transmission.
18 RI EXTENDER_PIN(15) The default behavior of the RI isIdle -> RI keeps at high levelURC -> RI outputs 120ms low pulse when a new URC returns.
19 ON/OFF EXTENDER_PIN(14) This pin can be used to Turn the SIMCOM800 module ON and OFF. When SIMCOM800 is in power down mode, it can be turned on to normal mode by driving the pin to a low level for at least 1s and release.Driving the PWRKEY pin to a low level voltage for at least 1s, the module will execute power-downprocedure after the PWRKEY is released.

Hardware Overview

_images/2GTopLegened.png

SIMCOM SIM800L

_images/SIM800-SIM800L-GPRS-GSM-Module.png

The SIMCOM SIM800L is a compact quad-band GSM/GPRS module supporting frequencies 850/900/1800/1900MHz. It features GPRS multi-slot class 12/10, a full modem serial port, USB for debugging and software downloads, and an audio channel with two microphone inputs and a speaker output. The module supports AT commands, has low power consumption, and operates in temperatures from -40 to 85°C. Ideal for data transmission, SMS, and voice applications, it includes interfaces for SIM cards, USB, GPIO, and more.

For further detail Please refer to SIMCOM Website .

GSM FPC Antenna

_images/2G_antenna.png
  • Frequency: 700-960MHz,824-960MHz, 1710-2700MHz
  • Impedance: 50 Ohm
  • S.W.R <= 3
  • Gain: 6dbi± 0.7dbi
  • Size: 60x8x0.2mm
  • Connector: ipex1 connector

2G Daughter Board Operation

Before connecting the 2G daughter board to the computer, ensure the following:

  • The battery is connected and charged.
  • GSM antenna is connected to the ipex connectors.
  • Data SIM (Nano size) is inserted in SIM socket.
  • Headphone with MIC (for voice calling).
  • USB Micro B Cable (For Charging and data communication)

Powering On the Daughter Board

  1. Slide the Kill Switch towards the SIM jacket to power on the Daughter Board.
  2. Press and hold the modem ON/OFF button to turn on the 2G module.
  3. Release the button when modem power ON Status LEDs is illuminated(After some time, other LEDs should start blinking, indicating that the module has started successfully).
  4. Connect the daughter board to the computer using the USB Micro B cable.

Firmware Update Over USB

When connecting the 2G daughter board for the first time, driver installation is required.

  1. Go to “This PC”, right-click, and select “Manage”.

    _images/DeviceManager.png

  2. Navigate to Device Manager where unknown devices will be listed.

    _images/UnknownDevices.png

  3. Download the drivers from the Resources section and update the drivers.

    _images/UpdateDrivers.png _images/BrowseForDrivers.png _images/SelectDriversFolder.png _images/DriversUpdateFinished.png

  4. After successful installation, the devices will be properly listed in Device Manager.

    _images/DeviceDriversInstalled.png

The drivers have been successfully installed, allowing communication with the 2G daughter board.

We will now update the firmware of the daughter board using SIMCOM's Flash_tool.exe. (Downloadable from the Resources section: SIMCOM 800 Series Firmware Flash Tool Windows)

  1. Select the relative firmware and port according to the diagram

    _images/SelectFirmwareFolder.png _images/SelectConfigFile.png

  2. Press the “Start Download” button and restart the daughter board with power kill switch.

    _images/StartFirmwareDownload.png

  3. After you slide OFF and ON the kill switch, the download bar will show progress as in image below.

    _images/FimwareUpdateProgress.png

  4. After successfully uploading the firmware you will see a message window like in image below.

    _images/FirmwareUploadCompleted.png

  5. Now you have latest firmware on 2G daughter board. You can install the daughter board on the back of WiPhone.

2G Daughterboard and WiPhone Communication

Unlike the 4G daughter board, which can communicate with a PC via USB to send and receive various commands, the 2G daughter board can only receive AT commands through the UART port and send responses accordingly. Therefore, the 2G daughter board must be connected to the back of the WiPhone, and the UARTpassthrough app should be started

  1. Load WiPhone with the “UARTPassthrough” firmware.

  2. Install the 2G LTE daughter board on the back of the WiPhone.

  3. Connect WiPhone to the computer with a USB cable.

  4. On WiPhone, navigate to Tools -> Development -> UART Pass Through.

    _images/UARTPassThrough.png

  5. Set Baudrate to 115200 and press start.

    _images/UARTPassThroughApp.jpg

Note

The daughterboard can interact with a variety of serial applications. Users have the option to employ standard AT commands or create custom scripts. Please be aware that the daughterboard is under development, and specialized scripts or WiPhone Apps are not yet part of the offering.

General Function Test Using Windows Software

The SIM800's default baud rate is set to "Auto-baud." To manually set it to 115200, send the following AT commands:

[TX] - AT<CR><LF>
[RX] - AT<CR>
<CR><LF>
OK<CR><LF>
[TX] - AT+IPR?<CR><LF>
[RX] - AT+IPR?<CR>
<CR><LF>
+IPR: 0<CR><LF>
<CR><LF>
OK<CR><LF>
[TX] - AT+IPR=115200<CR><LF>
[RX] - AT+IPR=115200<CR>
<CR><LF>
OK<CR><LF>
[TX] - AT+IPR?<CR><LF>
[RX] - AT+IPR?<CR>
<CR><LF>
+IPR: 115200<CR><LF>
<CR><LF>
OK<CR><LF>

We used Docklight as a serial communication tool for interacting with the daughter board. You can use any preferred serial software.

_images/SettingBaudRate.png

To test the general functions of the 2G daughter board, you can either write custom scripts or use AT command tester software. Here, we will be using Quectel Qnavigator, which we already used for testing our 4G daughterboard. (The Qnavigator software (Qnavigator_V1.6.8.zip) can be downloaded from the Quectel Tools archive in the Resources section of the 4G daughterboard documentation.)

  1. Launch the software, Go to “Serial port parameter setting” and select the correct “AT Port”.

    _images/SelectingATPort.png

  2. Uncheck the automatic initialization button and press the connect button.

    _images/UncheckAutoInitialization.png

  3. Click “Connect to module” to load Module and Network information.

    _images/ModemInfo.png

Call Test

  1. Check signal strength by sending “AT+CSQ” from the “AT command” Menu under “Network Service Commands”.

  2. Record the value in the output window. For example, “+CSQ: 26,99” indicates excellent signal strength.

    _images/SignalQualityCheck.png

  3. Insert the headphone with MIC into the audio jack connector on the 4G daughterboard.

  4. Go to the “Voice Call” Menu, enter the desired number, and press “CALL”.

    _images/Calling.png