Introduction:

HuaDuino is Arduino Nano compatible with enhancements that featuring 12 connectors for RC servo,  high power output regulator,  external UART connector and  3.7V lithium battery charging circuit. Integration design reduces mistakes on wiring different modules together.

Integrating a 40W (5V, 8A) power regulator allows it to drive high load electronics. The power regulator part can take input of 3.7V lithium batteries and then stepping up to output 5V and 3.3V to connected electronics. With two XH2.54 battery connectors it can embrace very large capacity power in separated battery packs.  The second battery connector can be used to chain up 2nd boards which makes single battery pack to power up multiple boards.  A switch controls the input power on/off. The external on/off switch connector gives convenience to application.

The built-in charging circuit can charge the batteries without disconnecting battery for recharging scenario. Charging port is standard micro USB socket which people  can do charging with any 5V USB power source.  Without battery connecting, this port is also the power source to power up. In addition, external pins for connecting different power socket type are also provided.   

With such many good features and characteristics, it allows people to do any Arduino projects a lot of easier.

 

HuaDuino Board Layout

Specifications:

  • Microcontroller Atmel ATmega328P-AU
  • Power chip Ti TPS61088RHL, supplies 5V/8A output power
  • Silicon CP2112 USB to TTL serial chip
  • 2A input battery charging module
  • Input Voltage 2.8v -5.5 V 
  • Digital I/O Pins 14
  • Analog Input Pins 8
  • Flash Memory 32 KB of which 2 KB used by bootloader
  • SRAM 2 KB 
  • EEPROM 1 KB
  • Clock Speed 16 MHz
  • Length 55 mm
  • Width 45 mm
  • Weigth 30g

 

Power Supply:

HuaDuino can be powered via the micro USB connector or/and  the battery connectors.  Battery connector is XH2.54 type. Most commonly battery to use is 3.7V lithium ion or polymer battery.  Batteries can be re-charging via internal charging circuit. To drive RC servo or cases needing high power consumption, the battery input should be used. The on/of switch controls it to power up.

 

Connector Description: 

HuaDuino I/O pin assignments and functionality  are compatible to Arduino Nano with following exceptions. Serial communication on  pin D0 (RX) and pin D1 (TX). used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the FTDI USB-to-TTL Serial chip or the UART connector  by sliding the switch (S1).  The UART connector is useful for connecting Bluetooth UART/LTE module , ESP8266 WiFi module, NRF24L01+ 2.4G RF module and etc. to allow wireless remote control application.  Moreover,  D13 is not connected to built-in LED. Following figure shows the connector description. There are also extra 5V/3.3V output pins.  Be careful not shorting the 5V/3.3V power output pins, the board will be damaged in such circumstance.

HuaDuino Connectors

 

Communication:

HuaDuino supports I2C, SPI and UART communication.

 

Programming:

To program HuaDuino, people can use Arduino native development tool known as Arduino Software , select "ArduinoNano w/ ATmega328" and the port  the OS assigned from the Tools > Board menu after you run Arduino Software IDE platform. HuaDuino comes with preburned bootloader that allows people to upload new code to it directly in Arduino Software. But to success uploading Arduino sketch, the middle switch (S1) on the board must be set to "USB" position and to have the USB driver installed to your OS platform.

Although it is not common, people can use ISP programmer to upload a program to microcontroller through the ICSP (In-Circuit Serial Programming) header.

Another alternative is Scratch programming language. An implementation known as Scratch for Arduino can be downloaded.  Scratch is designed especially for ages 8 to 16, but is used by people of all ages.

On Windows and MacOS you will need to install USB to TTL serial driver. On Linux, it already has driver. You should find the port something like /dev/ttyUSB{0,1,2 and etc} when attaching it to usb port of your computer.

 

USB to TTL Serial Driver Download:

http://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

 

Project:

A 3D printed 8 DOF quadruped robot has be implemented using HuaDuino. It is built with 8  of MG996R high torque servos.  With the high power regulator 8 high torque servos work very well.  A SPP-C Bluetooth UART module is the medium for the Android app to control it. The app can be downloaded from Google Play.