Getting Started with SIM808 IoT Board: Setup & Guide

This article offers a detailed guide on setting up and using the SIM808 module with Arduino, focusing on key pin notes, battery usage, and configurations for optimal functionality.

*12 Battery Usage:
- If you attached a 3.7V Li-Battery as power supply, remember to remove the Jumper from NO-BAT (Num.12) or it will reduce the battery's life.
- Even USB connection, please remove the jumper cap.
- If you don't connect USB port or VIN power supply, make sure the jumper connected.

*9 BOOT:
- Short press to power on SIM808
- Long press (3s) to power off SIM808

*Arduino D12 pin:
- Arduino D12 pin has been connected to the module power switch. You can set the pin HIGH/LOW to turn the SIM808 module ON/OFF in code.
- The D12 pin will become inactive if the board is powered through a VIN pin by a 7-23V DC power supply, and SIM808 will auto startup in this case.

*17 MIC jack:
- The MIC jack shares the same traces as the onboard MIC, so if you insert an external microphone, MIC (16) will become inactive.

About JP2 (RI/DTR Pins)

Description on back view

Connect RI with D8 with a Jumper

This port gets the working state of the board in code. By connecting the Arduino digital pins to DTR or RI, you can read the text info on the board's back. e.g. If I connect D8 to RI, then I could know RI pin state by writing this line in code:

// Example: Read RI pin state (connect D8 to RI)
RI_state = digitalRead(8);
pinMode(8, INPUT); // Add to setup()

1. DTR Description

DTR - Data terminal ready. The user can control the SIM808 module to enter or exit sleep mode(AT+CSCLK=1) by DTR signal or by pulling down the DTR pin. The serial port will become active after the DTR pin is pulled to LOW for 50ms.

2. RI Description

RI - Ring Indicator. The behavior of the RI pin is shown in the following table when the module is used as a receiver:

State	RI Response
Standby	HIGH
Voice Call	LOW (returns to HIGH when call is established or hung up)
Data Call	LOW (returns to HIGH when call is established or hung up)
SMS Received	The pin is changed to LOW, and kept low for 120ms when a SMS is received. Then it is changed to HIGH.
URC Received	The pin is changed to LOW, and kept low for 120ms when some URCs are reported. Then it is changed to HIGH.)

The behaviors of the RI

Precautions and Must-Do Steps for First-Time Use

Install the SIM card in the sim slot on the back of the board
- Make sure your SIM card is available, and you can put the SIM card into the socket or get it out by sliding the metal lock.
Install the GPS & GSM antennas on the board
Connect with PC and power supply(there are three ways to supply the power):
1. Through 7~23V power supply jack
2. Through VIN pin on board
3. Remove the jumper on NO BAT?, and connect a 3.7V Lithium Battery to BAT jack
4. After connecting the board to PC by an USB cable, the board shows up as Leonardo automatically if you have installed the Arduino by .exe file, or you will need to install the driver manually
BOOT SIM808 by pressing the BOOT white button for 2 seconds if the NET indicator LED is OFF.