The Nyboard V1 used by Bittle uses the Atmel ATMEGA328P controller, which only supports only one serial port. We separate the serial port of Nyboard to support more modules. The pins of the serial port are compatible with the 6-pin Arduino Pro Mini. Pin definitions are shown in the table below:
Modem signal DTR，reset NyBoard after serial download finished.
ATMEGA328P RX (receive)
ATMEGA328P TX (send)
5V power for MCU and chips
The default serial baud rate is 115200bps.
There're 3 communication modules for the NyBoard V1:
ESP8266 WiFi module
Bluetooth dual mode（EDR & BLE）JDY-23
The module uses CH340C USB bridge. Windows10, Linux and MacOS are all drive-free.
Insert the 6-pin(H1) to the NyBoard's downloader and then connect the module with the Micro-USB cable in the package to your PC. Open the Arduino IDE and select the corresponding COM port. You can download the programme and communicate with the NyBoard.
Another usage of the downloader is update the WiFi and bluetooth module's firmware. Plug the module in the female 6-pin socket. We changed the TX and RX pin and make one GND pin to the DTR to reset the WiFi module. The details are written in the chapter of the WiFi and bluetooth manual.
Do not plug the NyBoard and the module at the same time! That will make a mistake.