Function features
1. Input voltage range 5V-18V DC;
2. Self-propelled SIM card slot design, support 2G / 3G / 4G card or small card;
3. Module will connected to the network automatically after you power on it;
4. Compatible with a variety of single-chip serial port;
5. Reserved headset and microphone interface;
6. Support TTS DTMF function;
7. Bluetooth 3.0 protocol, enhanced Bluetooth antenna, support for serial port SPP and audio services;
8. Reserved lithium battery-powered BAT interface, you can use 3.7V lithium battery or 18650 lithium battery;
9. Reserved IPEX interface, SMA interface, spring antenna interface, can be used on different occasions;
10. With work indicator: the LED will flash 1 time per second when no network, no SIM card or SIM card inserted, and will Flash 1 time per 3 seconds under normal conditions.
Hardware introduction and description
1.Board size: 40.9*51.3mm
2.Functions of the board
(1)Interface description
GND: Power ground
VCC_IN: Power supply pin, input DC5V-20V
RI: Ring indicator
DTR: Data terminal preparation
TXD: TTL serial port transmission
RXD: TTL serial port receive
U2_R: module serial port 2 receive
U2_T: module serial port 2 send transmission
V_M: connect to the core voltage (5V/3.3V,it depend on your MCU) of MCU for level match(generally, NC also be OK for this pin)
ADC: ADC detection
SPP: Audio output positive
SPN: Audio output negative
MC-: Audio input negative
MC +: Audio input positive
PWR: Power enable or disable(enable when low level)
BAT: lithium battery input pin, 3.3V-4.4V
3.Basically instructions
The SIM800C mainly controlled by AT commands, so just find a USB convert to TTL serial port module,and 5V,GND,TXD,RXD pins connect to VCC_IN, GND,RXD, TXD pins of SIM800C
When the module is started, the indicator LED flashes once every 1 seconds, and after a period of time, the indicator LED flashes once every 3 seconds, it means the SIM800C start works normally.
