Bluetooth microcontrollor selection guide

Name	Bluno	Beetle ESP32	Beetle BLE	Romeo BLE	Romeo BLE mini	Bluno Nano
SKU	DFR0267	DFR0575	DFR0339	DFR0305	DFR0351	DFR0296
Microcontroller	ATmega328	ESP32	ATmega328	ATmega328P	ATmega328P	ATmega328P
BLE Chip	TI CC2540	ESP32	TI CC2540	TI CC2540	TI CC2540	TI CC2540
Power supply interface	USB or DC2.1	USB	USB	USB	USB	USB
USB Powered or External (V)	7 - 12	3.5 - 6.5	6 - 8	5 - 23	6.5 - 10	7 - 12
Operating Voltage (V)	5V	3.3V	5V	5V	5V	5V
Bootloader	Arduino UNO	Firebeetle ESP32	Arduino UNO	Arduino UNO	Arduino UNO	Arduino UNO
Flash(KB)	32	16M	32	32	32	32
SRAM(KB)	2	520	2	2	2	2
Analog pins	6	4	4	8	8	8
Digital pins	14	4	4	14	4	12
UART	1	1	1	1	0	1
I2C	1	1	1	3	1	1
SPI	1	1	1	1	0	1
Download Mode	Micro USB, Wireless	Micro USB	Micro USB, Wireless	Micro USB, Wireless	Micro USB, Wireless	Micro USB, Wireless
Maximum transmission distance (M)	30	30	30	70	30	50
Arduino UNO Compatible	√	×	√	√	×	×
Master/slave switch	√	√	√	√	√	√
Bluetooth passthrough	√	√	√	√	√	√
Bluetooth 4.0 wireless program	×	×	√	√	×	√
iBeacons	√	√	√	√	×	×
Bluetooth HID	√	×	√	√	√	√
App Control	√	√	√	×	√	√
Dimension(mm)	75*54	35*34	28.8*33.1	94*80	45*38.5	53*19
Weight (g)	50 g	12 g	10 g	62 g	25 g	17 g
Price($)	$24.9	$14.9	$14.9	$39.5	$25.9	$24.9
Key Features	can directly  connect with app, no pair need	Integrate a Dual-Core ESP-WROOM-32 module. Support MCU and Wi-Fi &Bluetooth dual-mode communication. V shaped gilded I/O interface, can be sewn on clothes directly.	Mobile BLE APP Connection Support. V shaped gilded I/O interface, can be sewn on clothes directly.	Mobile BLE APP Connection Support. Two way H-bridged Motor Driver with 2A maximum current and wireless socket.	Mobile BLE APP Connection Support. 1.2A single-channel continuous drive current and 3.2A current H-bridge Motor Driver interface.	Can upgrade BLE firmware via USB, integrate with mobile Bluetooth into a star network without pair

Name	Bluno Mega 2560	Bluno Mega 1280	Bluno M3	Bluno M0	FireBeetle BLE4.1	FireBeetle ESP32
SKU	DFR0323	DFR0306	DFR0329	DFR0416	DFR0492	DFR0478
Microcontroller	Mega2560	ATmega1280	STM32 F103RET6	NUC123ZD4AN0	ATMEGA328P	ESP32
BLE Chip	TI CC2540	TI CC2540	TI CC2540	TI CC2540	TI CC2540	ESP32
Power supply interface	USB or DC2.1	USB or DC2.1	USB or DC2.1	USB or DC2.1	USB	USB
USB Powered or External (V)	5 - 23	5 - 23	7 - 12	7 - 12	3.7 - 5.5	3.3 - 5.0
Operating Voltage (V)	5V	5V	3.3V	5V	3.3V	3.3V
Bootloader	Arduino Mega2560	Arduino Mega1280	Bluno M3	Bluno M0	Arduino Pro or Pro Mini	FireBeetle-ESP32
Flash(KB)	256	128	512	68	32	16M
SRAM(KB)	8	8	64	20	50	520
Analog pins	16	16	11	6	6	5
Digital pins	54	54	39	31	14	10
UART	4	4	5	1	1	1
I2C	2	2	1	1	1	1
SPI	1	1	2	1	1	1
Download Mode	Micro USB, Wireless	Micro USB, Wireless	Micro USB, Wireless	Micro USB, Wireless	Micro USB	Micro USB
Maximum transmission distance (M)	30	30	30	30	30	50
Arduino UNO Compatible	√	√	×	×	×	×
Master/slave switch	√	√	√	√	√	√
Bluetooth passthrough	√	√	√	√	√	√
Bluetooth 4.0 wireless program	√	√	√	√	√	×
iBeacons	√	√	√	√	√	√
Bluetooth HID	√	×	√	√	×	×
App Control	√	√	√	√	√	√
Dimension(mm)	100*53	100*53	68.7*31.3	68.5*53.4	58*29	24*53
Weight (g)	45 g	45 g	30 g	30 g	20 g	24 g
Price($)	$29.9	$19.9	$29.9	$24	$18.9	$24.9
Key Features	Mobile BLE App Support. Compatible with all Arduino Mega pins. Flash capacity: 256KB (4k for bootloader)	Mobile BLE App Support. Compatible with all Arduino Mega pins. Flash capacity: 128KB (4k for bootloader)	All 39 Digital I/O Pins can enable External Interrupt. 5 Serial Port.	The only ARM Cortex-M0 Arduino Microcontroller that supports 5V standard logic level. IIS interface supply. Wav files play & record support.	Support KISS connection (approach connection).  Support Bluetooth 4.1 multiple device cascade (maximum:4)	Integrate a Dual-Core ESP-WROOM-32 module. Support MCU and Wi-Fi &Bluetooth dual-mode communication.