The DFRobot FireBeetle series is a low-power controller designed for the Internet of Things (IoT) development. The FireBeetle BLE 4.1 controller integrates low-energy Bluetooth 4.1 with an Arduino controller, providing similar functionality to the Bluno series but with reduced power consumption. It features a stable DIALOG Bluetooth 4.1 chip that supports up to 4Kbyte/s transmission speed and has low power consumption, making it suitable for portable and smart tools. The controller also supports multiple Bluetooth cascades, KISS connections, and is compatible with the Bluno series.

Features

• Supports Arduino IDE programming
• Supports BLE 4.1 central and peripheral switch
• Supports Bluetooth serial port data transmission
• Supports Bluetooth peer-to-peer (P2P) wireless programming
• Supports Bluetooth 4.1 multiple device cascade (maximum: 4)
• Supports Arduino Bluetooth library (supports multiple Bluetooth connections)
• Supports low power consumption Bluetooth (standby current: 25uA; enabled interrupt current: 70uA)
• Double interruption to wake up:
  • BLE4.1 wakes Atmega328P by D2 (high level wake)
  • Atmega328P wakes BLE4.1 by D3 (low level wake)
• Supports KISS connection (approach connection)
• Supports Bluetooth firmware update
• Supports USB charging
• Supports lithium battery power supply
• Equipped with status LEDs

Specifications

• Processor: ATMEGA328P
• Bootloader: Arduino Pro or Pro Mini, ATmega328 (3.3V, 8MHz)
• Operating Current: 3.3V
• VCC I/O Voltage: 3.7V~5.5V
• Lithium Battery Voltage: 3.7V
• Maximum Transmission Rate: 4Kbyte/s
• Low Power Consumption: 25uA (POWER DOWN); 70uA (enabled interruption)
• Maximum Discharge Current: 600mA (LDO-3.3V OUTPUT)
• Maximum Charge Current: 400mA
• Digital Interfaces: 14
• Analog Interfaces: 6
• SPI: 1
• I2C: 1
• UART: 1
• LED_BUILTIN: D13
• Interface Mode: 2.54mm (Pin/Female header), soldering free in default
• Dimensions: 58 * 29 mm / 2.28 * 1.14 inches

Pinout

Setup Instructions

Choose a suitable Arduino board

Considering low power consumption, select Arduino Pro Mini @3.3V 8MHz as a bootloader for FireBeetle BLE4.1 microcontrollers.

Note: Pro Mini uses an 8MHz OCXO, which has a relatively slow processing speed for 115200-baud rate. The high baud rate may lead to unreadable code and packet loss, so 9600-baud rate is recommended.

Low Power Consumption Mode

BLE 4.1 switches to low power consumption mode with the AT command: AT+LOWPOWER=ON. The Bluetooth can still broadcast and connect in low power mode. When Bluetooth receives data, it will wake up automatically and send an interrupt signal to the chip: 328p. The interrupt pin should be connected to D2 of 328p which is interrupt 0 in the code.

Code

 void wakeup(){
 sleep_disable();
 delay(2000);
}
void lowpower(){
 ADCSRA &= ~(1< TWCR &= ~(1< delay(10);
 set_sleep_mode(SLEEP_MODE_PWR_DOWN); // Set sleep mode to power down mode
 sleep_enable(); // Enable sleep mode
 MCUCR |= (1< MCUCR = MCUCR & (~(1< sleep_cpu(); // Enter sleep mode
}
void setup() {
 attachInterrupt(0, wakeup, CHANGE);
 // Set interrupt method to trigger D2 to voltage change, callback function is wakeup(), which means awake functions of the chip 328p
 lowpower();
}
void loop() {
 lowpower();
 delay(2000);
}

Documentation

• Link

Package Includes

• 1 x FireBeetle Board-328P with BLE4.1
• 1 x USB Cable