A. UNV - SIM868 development board UNV - SIM868 development board by SIMCOM has launched a mobile module, superior performance, compact design.The onboard MICRO SIM kaka, reserved headphones mike welding mouth.Antenna interface for IPEX - MINI interface, small size, easy to connect various antenna.Onboard high efficiency DC - DC power supply module, support 5 v - 18 v wide voltage power supply, can reserve the power to make, convenient to control the power and reduce the power consumption of the development board.Master serial port has the do level match, support 3.3 V to 5 V microcontroller or other control systems. GPS + GSM GPRS beidou function. 2. Data supported by the module 1: support the GPS, BD, GLO, LBS base station positioning, omni-directional positioning 2: the RTC battery back-up, support hot start warm start, positioning speed is greatly enhanced 3: GPS positioning data to support independent acquisition and serial port configuration, more options, more convenient. 4: positioning data also support the GSM serial port, through the AT commands and configuration, more quick and easy. 5: computer debugging video a strong hit, make dear friends faster master 868 function 6: new various microcontroller program, greatly helped by single chip microcomputer rapid development 3. Module 1, rich interface, commonly used interface unified planning, integrated headphone jackLead to save space, with rows of needle 2, can we have make the power control pin, can control the power switch, can realize remote unmanned control.  3, the main serial port and the GPS serial integration level matching circuit, compatibility is very stable.  4, 2 status indicators, module state be clear at a glance, simple and quick.  5, 50 r antenna impedance matching, under the environment of good strong crazy GSM signal measured up to 31 is full,  6, exclusive firmware, support base station positioning, in times of poor GPS signals can normal position  7,The same quality, the same chip, our lowest price, the price is quite high.  Of the four modules  1. The RTC standby power: equipment after power off to the RTC power supply.  2. GPS power control pin: used to control internal GPS module part whether there is electricity, save electricity.  3. The GSM antenna interface: GSM GPRS antenna, IPX - MINI type antenna interface.  4. DC - DC module: using MSP series high reliability power supply chip, at the same time, the power can make pin leads.  5. The main serial port and power supply pins: serial port compatible with 3.3 V and 5 V controller, support the STM32 and other mainstream 51 MCU.  6. Active GPS antenna, GPS antenna.For the IPX - MINI type antenna interface.  7. Earphone interface: mike used to welding the voice interface, mike can realize mobile phone function.(we have sell microphones and speakers).  8. MICRO SIM booth: straight type insert SIM kaka, SIM card gouges where whole pieces were missing out when the card, support mobile unicom all kinds of mobile phone card.  5.