Maduino Zero SIM808 GPS Tracker is a board based on the Atmel SAMD21 32 bit microcontroller and on the GPS module GPRS / GSM SIM808. Programmable through the Arduino IDE, it can be used to create IOT (Internet of things) projects such as data acquisition, remote controls, GPS locators, etc. It has slots for micro SIM cards and micro SD cards; reset button for the SAMD21 microcontroller; micro USB connector for power supply and PC communication; 3.7 volt input for connecting a lithium polymer battery; 5 volt input for connecting a solar panel to recharge the lithium polymer battery; Status LED for power supply, battery charge, obtaining GPS position, status LED for the SIM808 and for the network status. The package includes the board already assembled and tested (except the strip connectors), the GSM and GPS antenna, the strip connectors (to be welded).

• Battery input voltage: 3.4 - 4.2 volts
• Microcontroller: ATSAMD21G18, 32-Bit ARM Cortex M0 +
• Clock: 48 MHz
• Integrated power control system
• AT command interface with "auto baud" detection
• Quad-band: 850/900/1800/1900 MHz
• Send and receive GPRS data (TCP / IP, HTTP, etc.)
• Slot for Micro SIM Card
• Slot for Micro SD Card
• GPS L1 C / A code
• Channels: 66
• Tracking sensitivity: -165dBm
• Acquisition sensitivity: -148dBm
• Time-To-First-Fix
  - Cold start: 32 seconds
  - Hot start: 1 second
  - Warm start: 5 seconds
• Accuracy: about 2.5 meters
• Interface: I2C / SPI / UART / 18 * GPIO
• Arduino compatible
• Operating temperature: from -40 ° C to + 85°C
• Dimensions (mm): 55x40x8

• LED 1PPS: shown the GPS position
• LED STA: indicates the status of the SIM808 module
• LED NET: indicates the status of the SIM80 network8
• LED PWR: Power status LED
• LED CHG: Battery charge status LED
• VBAT: 3.7 volt input for connection of lithium polymer battery
• CHG: 5 volt input to which a solar panel can be connected to recharge the lithium polymer battery
• Micro USB connector: 5 volt power input and PC communication
• IPX antenna connector GPS (included)
• IPX connector for GPRS / GSM antenna (included)
• Reset button: resets the microcontroller SAMD21⑥

• Demo code
• Schematic

• Which type of Arduino should be chosen for programming?
  "Arduino Zero (native USB port)" must be chosen for the programming phase;
• "Arduino Zero" is not present in the list of boards, how do you add it?
  From the Arduino IDE card manager (Tools> Card> Card Manager) look for "Arduino Zero", then install "Arduino SAMD Boards (32-bits ARM Cortex-M0 +);
• Why is the card recognized as "MKR1000"?
  The card is based on SAMD21, therefore it could be recognized in this way if it is in programming mode. When the board is recognized by the IDE as MKR1000 it can be programmed as it is in programming mode, while if it will be recognized as "Arduino Zero" it means that it has already been programmed and the program is running, in which case programming is not allowed ;
• How can you load the sketch after having already programmed the card? The board is recognized as "Arduino Zero" and cannot be programmed
  To switch to programming mode, it is necessary to press the RESET key on the board 2 consecutive times. Once this is done, the board will be recognized as "MKR1000" by creating a different COM from the previous one, then choose the correct COM and select "Arduino Zero" as the board.