Introducing BOBODUINO UNO

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What’s special about Boboduino?

Boboduino is a development board compatible with Arduino Uno, suitable for conceptual validation and prototyping of electronic circuits. It is designed for both beginners and experienced users. The main difference between Boboduino and Arduino Uno R3 is the replacement of the larger Type-B USB connector with a Type-C USB connector. In addition, BOBODUINOincludes the ability to charge a 3.7V lithium battery. Of course, the board can also be supply by the lithium battery. When connected to a USB cable together with the lithium battery, the battery can be charged. This feature makes it suitable for projects involving wireless monitoring or remote operation. Now, let’s go through the main differences between the BOBO board and the Uno board:

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Type-C USB

Boboduino Uno utilize a USB Type-C connector, which reduces the size of the USB port and decreases the board’s height. Type-C USB is more compact and offers superior advantages in terms of power delivery and data transfer speed. It is expected to become the mainstream technology in the future.

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5V power supply

The power supply is a significant difference between BOBODUINO UNO and Arduino Uno. On the BOBO board, you have the option to power it through USB or a 5V adapter while simultaneously charging the lithium battery. You may wonder why the black power jack, commonly found on the Uno board, is missing on the BOBO board. The reason we don’t include a 9-12V power jack is that when using the DC power jack to input 9-12V, it requires a linear voltage regulator (LDO) to step down the voltage to 5V. During this voltage conversion process, the linear regulator consumes some electrical energy and generates heat. The heat generated increases as the voltage difference becomes larger.

However, if you need to power the board with a 5V power supply, you can modify the power adapter wire with a 2.54mm JST connector. Supplying power through the JST connector would also make it easier to integrate the BOBO board into smaller and more stable project prototypes.

On the BOBODUINO board, you can power it through the Type-C USB or the 5V 2.54mm JST connector. The black switch located between the Type-C USB and the 5V JST connector is used to toggle between the two power supply options. This design primarily aims to prevent any voltage difference between the USB and 5V JST from causing reverse current flow. By using the switch to select the power source, it safeguards the USB or the adapter from potential damage when both are plugged in simultaneously.

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Charging Lithium Battery

The Boboduino UNO board includes a power management and lithium battery charging/supply circuit. You can charge the lithium battery directly using the Type-C USB or a 5V adapter on the BOBO board. During the charging process, the red “C” (Charging) LED on the board will illuminate, and once the battery is fully charged, it will switch to the green “F” (Full) LED. There are two main power supply methods. When an external power source is connected, such as the Type-C USB or a 5V adapter, the board will be powered by the external supply. In the absence of an external power source, the TP5410 IC on the board activates the boost function to increase the voltage from the 3.7V lithium battery to 5V. Additionally, apart from the 5V power system, the AP2112 IC on the board can be used to step down the voltage from 5V and obtain 3.3V.

📌 Note: When plug-in the lithium battery, It is important to pay attention to the polarity of the lithium battery. Connect the positive and negative terminals of the battery according to the symbols (+) and (-) as shown in the diagram. If the battery polarity is reversed, the "Error" indicator on the board will light up, and the "ON" power LED will not turn on. Additionally, for safety reasons, it is highly recommended to use lithium batteries with protection circuits boards. Although the BOBO board has basic overcharging and over-discharging protection, using lithium batteries with built-in protection circuits provides an extra level of safety. For more information on selecting the right lithium battery, you can refer to our [Battery Selection Guide].

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Switching between 5V/3.3V

In project development, there are times when we want to use sensors that operate at 3.3V, while the board itself is designed for 5V logic. In such cases, we need to use level-shifting modules to convert the voltage between the 3.3V sensor and the 5V logic. On the BOBO board, switching the voltage level is made easy. Simply remove the jumper cap from the 5V position in the center of the board and place it in the 3.3V position. This allows you to use peripherals that operate at 3.3V. If you need to use both 5V and 3.3V sensors simultaneously, you will need to use external level-shifting modules or ICs to interface with them. With a small modification, you can even adjust the BOBO board to operate at other voltage levels, such as 1.8V or 2.2V. We’ll provide more details on this later.

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More useful functions

Compared to the official Uno board that uses the ATmega328P IC, the Boboduino utilizes an upgraded version, the ATmega328PB. This means that while maintaining compatibility with Uno’s functionality, the Boboduino offers additional useful features. Here are some simple comparisons:

Digital Pins:

The Boboduino has 4 extra digital pins compared to the Uno, namely A6, A7, PE0, and PE1. Combined with the original pins found in the Arduino Uno, you have a total of 20+4 digital pins to work with. If you often find the digital pins on the Uno insufficient but feel that the Mega board is too large, you might consider whether the Boboduino board meets your needs.

Analog Pins:

In addition to the A0~A5 pins, the Boboduino has two extra analog pins, A6 and A7. These additional pins come in handy when you need to connect multiple external devices. A6 and A7 can be used as both analog inputs and digital inputs/outputs. In summary, A6/A7 offer the following functionalities:

• ADC (Analog-to-Digital Converter)
• Digital input/output

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More UART/SPI/I2C interfaces

Boboduino has also added an additional set of UART, SPI, and I2C (IIC) interfaces, making it more convenient to connect with external devices and sensors.

• UART (Universal Asynchronous Receiver-Transmitter): UART is a popular serial communication protocol used for transmitting and receiving data. With the additional UART interface on the Boboduino, you can easily communicate with multiple serial devices simultaneously.
• SPI (Serial Peripheral Interface): SPI is a synchronous serial communication protocol commonly used for interfacing with devices such as sensors, displays, and memory chips. The extra SPI interface on the Boboduino allows for more flexible and convenient connection options.
• I2C (Inter-Integrated Circuit): I2C, also known as IIC (Inter-IC), is a widely used serial communication protocol for connecting multiple devices on a shared bus. The additional I2C interface on the Boboduino enables seamless integration with I2C-compatible devices, such as sensors, EEPROMs, and real-time clocks.

By providing an extra set of UART, SPI, and I2C interfaces, the Boboduino offers greater versatility and ease of use when connecting with external devices and sensors.

Communication protocol	BOBO	UNO
UART	2 sets	1 set
SPI	2 sets	1 set
IIC	2 sets	1 set

On the Arduino Uno, there are six PWM (Pulse Width Modulation) pins, while on the Boboduino, three additional PWM pins have been added, totaling nine PWM pins:

Boboduino: 0, 1, 2, 3, 5, 6, 9, 10, 11 

Arduino Uno: 3, 5, 6, 9, 10, 11

By adding extra PWM pins, the Boboduino offers increased flexibility and convenience when controlling various devices and performing precise electronic adjustments.

Here is a comparison table highlighting the specific differences between the Arduino Uno R3 and Boboduino:

We will continue to provide more detailed information about the features of the Boboduino later on. For a more in-depth introduction to the pinout and functionality, please refer to the [Pinout illustration]section.

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Reference

• Getting Started with Arduino
• ATmega328PB Datasheet(PDF)