Sim 900 A-Mini Board Features:

• Power supply by 5V, can be powered by USB, for long term use it is better to still use 1A current power source. XH2.54-2P connector.
• TTL 5V and 3V3 interface (yellow pins marked on board), compatible with arduino, STM32, raspberry pi, etc.
• On board RS232 interface, easy for debugging. On the left, white pins.
• On board ring signal LED, on the left-top corner of SIM900A IC.
• On Board reset and restart pins, on the bottom of the SIM900A IC.
• Reserved IPX mini connector, but not yet soldered.
• Standard SMA antenna connector.
• Serial port is protected by TVS and beads circuit, to prevent any surging current or HV.
• SIM circuit has SMF05C electrostatics releasing IC.
• Package includes antenna and DC jack.
• Do NOT have audio power jack on board, which means you can't hear or speak through the call.
• Board size is 5×5 CM

Package Included:

• 1 X Sim 900 A V4.0 kit
• 1 X Power Cable
• 1 X Antenna