This board based on the latest SIMCOM SIM808 GSM/GPS module, it offers cellular GSM and GPRS data along with GPS technology for satellite navigation.
The board features ultra-low power consumption in sleep mode, giving the project incredibly long standby times. Furthermore there's an onboard battery charging circuit that can be used with LiPo batteries.
- GSM/GPRS SLEEP. Module will automatically go into sleep mode if the conditions of sleep mode are enabling and there is no on air and no hardware interrupt (such as GPIO interrupt or data on serial port). In this case, the current consumption of module will reduce to the minimal level. In sleep mode, the module can still receive paging message and SMS.
- GSM IDLE. Software is active. Module registered to the GSM network, and the module is ready to communicate.
- GSM TALK. Connection between two subscribers is in progress. In this case, the power consumption depends on network settings such as DTX off/on, FR/EFR/HR, hopping sequences, antenna.
- GPRS STANDBY. Module is ready for GPRS data transfer, but no data is currently sent or received. In this case, power consumption depends on network settings and GPRS configuration.
- GPRS DATA. There is GPRS data transfer (PPP or TCP or UDP) in progress. In this case, power consumption is related with network settings (e.g. power control level); uplink/downlink data rates and GPRS configuration (e.g. used multi-slot settings).
- Charge. The mode support charge function (Default is closed).
2. Power off
Normal power off by sending the AT command “AT+CPOWD=1” or using the PWRKEY. The power management unit shuts down the power supply for the baseband part of the module, and only the power supply for the RTC is remained. Software is not active. The serial port is not accessible. Power supply (connected to VBAT) remains applied.
3. Minimum functionality mode
AT command “AT+CFUN” can be used to set the module to a minimum functionality mode without removing the power supply. In this mode, the RF part of the module will not work or the SIM card will not be accessible, or both RF part and SIM card will be closed, and the serial port is still accessible. The power consumption in this mode is lower than normal mode.
You can find the SIM808 datasheet, programs to upload new firmware and other documents here and here.
Handling GPS Data
Once the GPS receiver has transmitted the NMEA sentences to the Arduino, and they have been properly read and stored in nice and "simple format", then what follows?
There are several options to convert the "simple format" data into more general format (GPX, KMZ, etc.). For instance:
- GPS Visualizer is a free online utility "that creates maps and profiles from geographic data". You can input a CSV or tabbed file, a spreadsheet, or drag and drop the data. The appearance of the page is a bit odd but the content is good.
- GPS Prune is intended to view, edit and convert GPS data. It allows to load text files as well as NMEA files, among quite a number of other options.
- GPS Babel seems to be the most known GPS data converter. It reads text files with NMEA sentences.
U‑center GNSS evaluation software for Windows
The u‑center GNSS evaluation software for automotive, mobile terminal and infrastructure applications provides a powerful tool for evaluation, performance analysis and configuration of u‑blox GNSS receivers. Its unique flexibility makes the u‑center GNSS evaluation software an invaluable tool for evaluation, analysis and configuration of u‑blox GNSS receivers. u‑blox GNSS receivers can be configured using the u‑center evaluation software.
- Highly interactive and easy to use
- Full support of all u‑blox GNSS receivers
- Extensive configuration and control features
- Real‑time display from a GNSS receiver via RS232 and USB interface
See more details here.
Signals and connections of the USB to TTL converter
You can read more about them here.
Signals and connections of the SIM808 GSM GPRS GPS Bluetooth evolution board (EVB-V3.2)
RX (or RXD) - receive data input pin. Connected to Arduino board or USB to TTL converter TX pin.
TX (or TXD) - transmit data output pin. Connected to Arduino board or USB to TTL converter RX pin.
V_IN - power supply 5-26VDC
LI-ion + - positive pin for Li-Ion battery 3.5-4V DC
LI-ion - - negative pin for Li-Ion battery 3.5-4V DC
POWKEY - start button. press it to start the module
VMCU - The pin of VMCU is used to control the high level of TTL UART, so as to realize to match between 1.25V/3.3V /5V systems. For example, if you want to use the 51 MCU to control this board, the pin of VMCU should be connected the DC5V. And if use the STM32 MCU, the pin of VMCU should be connected the DC3.3V.
GND - ground. Connected to Arduino board GND pin.
MIC - microphone jack input. An external microphone connected to it.
EPP - speaker or headphone jack output. Speaker or headphone connected to it.
PPS - Pulse per second. This is an output pin on some GPS modules. Generally, when this pin toggles, once a second, you can synchronize your system clock to the GPS clock.
MOTO - Vibration motor
SDA - I2C serial bus data I/O pin
SCL - I2C serial bus clock output pin
NET - Network status.
STA - Power on status
DTR - Data terminal ready input pin. Used for Serial communication.
2.8V - power supply 2.8VDC
RI - Ring indicator output pin.
CTS - Clear to send output pin.
RST - Reset input(Active low)
D9 - GPIO pin.
RTS - Request to send input pin.
DCD - Data carrier detect output pin.
The power supply range of SIM808 is from 3.4V to 4.4V. Recommended voltage is 4.0V.The transmitting burst will cause voltage drop and the power supply must be able to provide sufficient current up to 2A.
1. Using Arduino board
2. Using USB to TTL converter
Step by Step instruction
1. Configuring the GSM GPRS GPS Bluetooth module with Arduino board.
- Do wiring.
- Attach GSM, GPS and Bluetooth antennas to GSM GPRS GPS Bluetooth module.
- Insert a valid unlocked SIM card to SIM card slot of GSM GPRS GPS Bluetooth module.
- You can power up GSM GPRS GPS Bluetooth module with power supply adapter (5-26VDC 2A) DC044 interface, with V_IN pin (5-26VDC 2A) and with Lithium Ion battery 3,5-4VDC.
- We used the 5VDC 2A power adapter. Push the power switch to ON position - towards the SIM808 IC. When the module powered on, the LED power on indication (PWR) will be ON.
- Press Start button for 2 seconds. Status indication LEDs (NET, STA, PPS) will be ON. One of them starts to flash (1 second on, 1 second off) - SIM808 begins to work. If the power supply, GSM, Bluetooth, GPS antennas and SIM card connected to the module correctly, the LED will be flash slowly (1 second on, 3 seconds off), that indicates that the module is registered to the network, and you can make a call or do something else.
- Open Arduino IDE.
- Plug your Adruino Uno board into your PC and select the correct board and com port
- Verify and upload the ATsetupsketch to your Adruino Uno
- Open the Serial Monitor at a baud rate of 9600. Both NL & CR must be selected too.
- First you need to check if AT commands are working - enter “AT” and press button Send.This would print OK which signifies of working connection and operation of the module.
- Enter “AT+GMI<