BLE-Nano mainboard with BLE 4.2 compatible for Arduino Nano V3.0, compatible with TI CC2540, Type-C

github link:   https://github.com/emakefun/ble-nano

• The BLE chip: RISC-V architecture ch57xF chip (highly compatible with TI CC2540 Bluetooth SOC).
• Working channel: 2.4G
• When the transmission power is 0 dBm, the current is 6mA.
• The receiving sensitivity is -96 dBm, with a programmable +5 dBm transmission power.
• In an open environment, the communication distance is approximately 170m with a transmission power of 0 dBm and approximately 240m with a transmission power of 3 dBm.
• The device supports three types of communication interfaces: USB serial, Arduino serial, and Bluetooth. It can be configured using AT commands, and it also supports switching between master and slave modes.
• The device supports USB virtual serial port, hardware serial port, and BLE three-way transparent transmission.
• In host mode, the device supports automatic Bluetooth connection to a slave device.
• MTU:67
• Support mobile phone download program

• Processor: ATmega328P-MU QFN32
• Digital IO pins: 22 (6 of them used as PWM output).
• Analog input pins：8 (A0~A7)
• DC current of IO pins：40mA
• Current of the 5V pin: 500mA when VIN is input.
• Current of the 3.3V pin: 500mA.
• Flash memory: 32KB (0.5KB of which is used for bootloader).
• SRAM： 2KB
• EEPROM： 1KB
• USB to Serial chip: CH57xF chip, compatible with official Arduino Uno drivers.
• Working clock：16 MHZ