3.3V/5V TTL Level Control Development Learning Board 51 STM32 SIM800 GSM GPRS Module SIM900a SIM800 Module
Basic functions
SIM800 module is sim company's GSM / GPRS module. The development board supports Unicom mobile 2g / 3g / 4g card.
1.DC6-24v wide voltage power supply, can also be used with your system power supply. Board high-performance DC-DC power supply circuit, coupled with TVS protection, the system greatly improved the stability
2. Support 3.3V / 5V TTL level control, convenient and a variety of commonly used single-chip, 51 / STM32 and other communications
The module lists TX / RX / GND separately, and is convenient for use
3. With a standard serial interface, can be easily controlled by PC or debugging
4. With headphone and microphone interface, can easily test the GSM voice call function
5. With SIM card electrostatic protection chip, plug the SIM card when the static electricity generated protection
6. All available SIM800 pins are available for easy development of various SIM800 applications
7. With RTC backup battery
8. With NET_STA indicator, easy to watch the current SIM800 state.
| Power supply | DC6-24v |
| Board size | 83mm * 54mm |
1. TTL level control interface, can be directly connected to the single-chip serial port 5v/3.3v level logic, or usb-ttl module computer debugging
2. Logic level conversion circuit (important), automatically convert the TTL level to the 2.8v level required by the core. Many other shop designs do not have this part of the circuit or just a simple series resistor, which causes the module to be connected to the TTL of the microcontroller serial port. Burned out.
3. Microphone and headphone interface for testing voice call function
4. TTL level and RS232 serial port control switch short circuit cap
5.RS232 serial port interface, can be connected to the serial line and computer communication debugging.
6.MAX3232 serial port conversion circuit
7.Vbat power interface, DC-DC regulated output interface
8. DC power adapter input interface, it is recommended to use 9v or 12v power input (at least 1A), because the GSM module instantaneous power consumption can reach 2A@4v
9. Power indicator
10. Power switch
11.RTC battery
12.SIM800 core (Quad Global Access)
13.SIM card base
14. Signal indicator 15. ESD protection chip 16. Module start button switch 17. SIM800 core expansion pin 18. SMA interface small pepper antenna 19. DC-DC switching power supply voltage regulator