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EC41 Bluetooth module is designed for intelligent wireless data transmission and to create, by the United States TI's CC2541 chip configuration 256Kb space, follow the Bluetooth specification V4.0 BLE. Support AT commands, the user can modify the serial port baud rate, device name, password and other parameters pairing, use and flexible.

The module supports UART interface, low cost, small size, low power consumption with the transceiver sensitive advantages, only external components can be achieved with a little of its powerful features.

  • Bluetooth protocol: Bluetooth Specification V4.0 BLE, receive no byte limit, under open environment iphone4s can achieve 110 m long distance communications
  • Operating Frequency: 2.4GHz ISM band
  • Modulation: GFSK (Gaussian Frequency Shift Keying)
  • Sensitivity: ≤-84dBm at 0.1% BER
  • Transfer rate: Asynchronous: 6 kbps Synchronous: 6 kbps
  • Security Features: Authentication and encryption
  • Support Services: Central & Peripheral UUID FFE0, FFE1
  • Power consumption: automatic sleep mode, standby current 400uA ~ 1.5mA, transmission 8.5mA.
  • Power supply: + 3.3VDC 50mA
  • Dimensions: 26.9mm x 13mm x 2.2 mm
  • Bluetooth Certification: ROHS REACH
  • Function: Master & Salve

Mechanical Features

  • Operating Frequency Band 2.4GHz ISM band
  • Bluetooth Specification BLE4.0
  • Output Power Class Class 2
  • Operating Voltage 3.3V
  • Host Interface UART
  • Memory Size 256KB
  • Dimension 27mm (L) x 13 (W) mm x 2mm (H)

Referential Application Schematic, Board Dimension

Pin definition

Pin No. Pin Name Pin Description

  • 1 UART_TX serial data output
  • 2 UART_RX serial data input
  • 3 UART_CTS Serial Clear To Send
  • 4 UART_RTS serial request
  • 5 NC N/C
  • 6 NC N/C
  • 7 P2_2 debug clock port
  • 8 P2_1 debugging data port
  • 9 P2_0 programmable input and output ports
  • 10 NC N/C
  • 11 RESETB low reset, at least 5ms
  • 12 VCC Power V3.3
  • 13 GND ground
  • 14 GND ground
  • 15 SDA data port
  • 16 NC N/C
  • 17 NC N/C
  • 18 NC N/C
  • 19 NC N/C
  • 20 SDL clock port
  • 21 GND ground
  • 22 GND ground
  • 23 P1_3 SW1 system keys, see other configurations
  • 24 P1_2 LED pin, see other configurations
  • 25 P1_1 host interrupt instruction mouth, idle is low, connect to high
  • 26 P1_0 programmable input and output ports
  • 27 P0_7 software / hardware master from setting selection port
  • 28 P0_6 hardware port from the main setup mode
  • 29 P0_5 programmable input and output ports
  • 30 P0_4 programmable input and output ports
  • 31 P0_3 programmable input and output ports
  • 32 P0_2 programmable input and output ports
  • 33 P0_1 programmable input and output ports
  • 34 P0_0 programmable input and output ports


Setup Maste/Salve

Bluetooth module supports hardware / software set master-slave mode, as follows:

Pin Low or NC High 3v3
27 setup mode by hardware setup mode by software AT commands
28 hardware slave mode Master

Status LED pin 24

Mode LED Status module status
master blink even: 300ms-on,300ms-off search and connecting
master ON connected
salve blink even: 300ms-on,300ms-off waiting pairing
salve ON connected

Sleep Mode

  • Module Sleep Settings

Only makes sense from the module Sleep mode, the slave mode via serial port to send "AT + SLEEP \ r \ n", if nothing unexpected happens, the module will return "+ SLEEP \ r \ nOK \ r \ n" and enter dormancy state, this state can be found to be connected.

  • Wake-up module is set in three ways:
  1. Method One: You can send the string length of about 80 to activate the module. This activation can not contain the string to send AT commands, after the success of wake, serial will output "+ WAKE \ r \ nOK \ r \ n" string.
  2. Method two: short press system button SW1.
  3. Method three: direct mating connector.
  • Key pin instruction

P1_3 as an input pin, short press control, you can perform the following functions:

  1. When the module is in hibernation: the module will wake up to a normal state after a successful wake, the serial will be a "+ WAKE \ r \ nOK \ r \ n" string.
  2. When the module is in the connected state: the module will initiate disconnection request.

AT commands

  • Baud rate 1200,2400,4800,9600/default,14400,19200,38400,57600,115200 and 230400bps
  • All commands need carriage return or \r\n
  • All commands can only work when NOT connected, data transmission mode when connected.
Commands Function parameters 0/1/ 2/3/ 4/5/6/7/8/9
AT+RESET reset -
AT+VERSION check version -
AT+LADDR set module address -
AT+NAME<Param> set name -
AT+PIN<Param> set pin password default 000000
AT+BAUD<Param> baud rate 1200,2400,4800,9600/default,14400,19200,38400,57600,115200, 230400
AT+STOP<Param> stop bit 1 stop bit / 2 stop bit
AT+PARI<Param> serial verify bit non/odd/even
AT+RESET restart -
AT+DEFAULT software reset module -
AT+PWRM<Param> whether enter into sleep mode when power up yes/normal start
AT+SLEEP enter into sleep mode -
AT+ROLE<Param> set salve/master moe salve(default)/master
AT+INQ search remote Bluetooth device -
AT+SHOW show the scanned remote device -
AT+CONN<Param> connect to remote device search 0-8 device ID
AT+POWE<Param> set module power -23dB/-6dB/0dB (default)/+4dB(Not supported)
AT+HELP help -

Layout Design note

CE41 Bluetooth module works in 2.4G wireless frequency bands, should try to avoid the influence of various factors on the radio, and note the following:

  • Bluetooth module housing enclosing the product to avoid the use of metal, when using part of the metal shell, should try to make the module antenna away from the metal part of the section.
  • Product internal metal cable or a metal screw, should be kept away from the module antenna section.
  • Module antenna part should be placed on every side by the carrier board PCB is not allowed to place in the panel, and below the antenna carrier plate milling empty, with the antenna parallel to the direction, do not allow laying copper or traces. Directly exposed directly to the antenna portion carrier board is a better choice.
  • Try to shop under the module large GND, traces as extending to the periphery.
  • Recommended placement position on the substrate module isolation insulating material, such as a piece of silk put in this position (TopOverLay)