"Can wear market fire, low-power Bluetooth natural work can not be!
Bluetooth initially created by Ericsson Company, a wireless communication technology, which is later developed by the Bluetooth Technology Alliance. In 2010, Bluetooth 4.0 is released, while Bluetooth SIG (Special Interest Group is responsible for promoting the development of Bluetooth technical standards and authorizing non-profit organizations to manufacturers) to rename Bluetooth Smart or Bluetooth Smart Ready. About Bluetooth new standards, Bluetooth Sig Chief Marketing Officer Suke Jawanda has commented: "In the past, when we talked about Bluetooth technology and data transmission, mainly considering the demand for the delivery of data in a longer period of time, mainly. Now, Fitbit Flex is now collecting data first, and then transmits data to the user's mobile phone in some time. "
Bluetooth is initially commonly used on mobile phones, and now Bluetooth is widely used in wearable devices represented by smart watches and various portable medical devices. Be
Mbed Ble Sensors Tag is a low-power Bluetooth development board launched by Linksprite (Liandi Puri) for R & D staff, Wucker, lovers assessment and learning. As can be seen from the name, this is a Mbed support for development board. The main control is Nordic NRF51822. It integrates LIS3DH, BMP180, Buzzer, LED lights, etc., in addition to this, Integrated an Mbed compatible programmer.
Unpack
Unpacking the courier, is a small cassette, which is the Mbed Ble Sensors Tag development board. This is the latest low-power Bluetooth development board for LinkSprite. Maybe everyone is not too familiar with LinkSprite, but if To PCDUINO, it's right, it is the PCDUINO, which is compatible with Arduino but is more powerful than it, you may have realized. Be
Positive packaging box, LOGO and logo, identification bar code and QR code are printed on the front of the box.
Suite family portrait
The development board is very small, the PCB uses white ink, the development plate is divided into two parts, the left is Ble Sensors Tag, integrated with the sensor such as Lis3DH, the circular PCB, is it possible to cut, with an LCD screen, make a block watch to play Play?
On the right is a JLINK-OB programmer for downloading procedures and modulation to the development board. The download / debugger in the development board has become a trend. From the Nucleo series of ST, GD32's series of development boards, all integrate corresponding debug / downloaders, so that users can quickly pick up, no need to prepare Jlink or Ulink or other dedicated download / debugger, not only It is only possible to save users, and it is also convenient for downloading / debugging.
On the back of the development board, the CR2032 battery holder is not soldered by default. Be
Sensor development board recommended:
The Arduino Microsight Module The first chip size Arduino is compatible, allows you to use a built-in Arduino's OLED display that you want to use.
Boosterpack MKII Multi-Function Sensor Evaluation Board provides an analog handle, environmental and motion sensor, RGB LED, microphone, buzzer, a top show for a colorful LCD display.
PSOC-4 Drive Suite A sensor-based low-power consumption networked application design, available in termination, smart home, medical equipment, sports fitness monitoring, and other wearable smart devices.
MBED entry
BLE SENSORS TAG supports MBED cloud development, that is, the device is Mbed Enabled.
What is MBED?
Mbed is a prototype development platform for the ARM processor, which specifically includes free software library (SDK), hardware reference design (HDK), and online tool (Web) three parts, and the specific introduction of each part is as follows:
SDK: Mbed designed a hardware abstraction layer, which shields different MCU vendors to provide microreating differences. For users, he only needs to deal with this hardware abstraction layer, that is, users based on Mbed development Applications can easily replace the ARM microprocessor using different vendors to leave more choices.
HDK: HDK is the hardware reference design provided by Mbed. It is designed for user development, so HDK provides a unified program upload interface, single-step debug interface, serial debug interface, and users can start software development work without purchasing other hardware.
Web: In order to save the user's development environment installation, Mbed provides a complete browser-based microprocessor software development environment, including code writing, program compilation, version control, etc., users can develop, compile results It is very convenient to work as long as the download is saved to the Mbed development board.
Regarding the mode of Mbed cloud development, all parties say that On the one hand, Mbed is a development method, a perfect hardware platform support, rich component library, which makes software development in the Mbed platform, which makes mobile development becomes a web mode engineering and code organization. Maybe, as long as you can access the Internet, you can write and download, you don't need to install a huge IDE tool chain, and there is also the code sharing and import more convenient. However, such a cloud development method is inconvenient in: The written code is stored in the cloud, downloading to a local HEX file, debugging is almost impossible. Fortunately, the MBED provides code to deport the local function, which deaches this contradiction to a certain extent. In addition, the Mbed component library has deep encapsulation and abstraction of the underlying detail of the hardware platform, and you need a deeper digging code base when Debug.
The so-called Mbed Enabled device is the development device that Mbed can support. In addition to component libraries written specifically for the corresponding equipment, the MBED board can run the MBED operating system - this is an internal operating system capable of controlling hardware and interacting with clouds in a simple, consistent manner. The operating system also implements internal integration with other tools. There is also your code on the MBED operating system, which is the code that is enforced by hardware processing and storage capabilities.
Mbed Ble Sensors Tag is a development board supported by Mbed. Next we will start to experience how to enter the MBED and prepare the development environment for the Mbed Ble Sensors TAG.
Open the browser and enter the MBED website in the address bar. If the user has not registered the development account of the MBED, you need to register a one and log in. The interface behind landing is as follows
Mbed supports rich hardware platforms, all hardware platforms have corresponding component libraries and underlying code support. Click on the red arrow marked by the red arrow to choose the Nordic NRF51822 hardware platform, as shown below
The specific development board models have a thousand differentiation. BLE SENSORS TAG uses NRF51822 as its master, here we directly select Nordic NRF51822 as a platform. Note that the image has been selected in the picture, if it is the first time you enter, first click on the Add PLATFORM button, then select the corresponding platform device.
In order to demonstrate the basic development process of the MBED, the next light is next.
Under the development interface of the Mbed, click the "New / New Program" menu to pop up the following dialog box
Sensor development board recommended:
The Arduino Microsight Module The first chip size Arduino is compatible, allows you to use a built-in Arduino's OLED display that you want to use.
Boosterpack MKII Multi-Function Sensor Evaluation Board provides an analog handle, environmental and motion sensor, RGB LED, microphone, buzzer, a top show for a colorful LCD display.
PSOC-4 Drive Suite A sensor-based low-power consumption networked application design, available in termination, smart home, medical equipment, sports fitness monitoring, and other wearable smart devices.
Note, don't choose the wrong platform, otherwise the bottom hardware library is incorrect; if you have to pay attention to the selection of Template, this is the other users on the network have been designed, we can choose it, you can Add or use it directly on the basis. Click OK, Mbed is created for us to create a project.
The left is the engineering manager, and the right is a specific file or component. It can be seen that Mbed has automatically joined us of the MBED's basic component support, and the generated project file contains a main.cpp file, Mbed based on C ++.
Double-click main.cpp, the file content is as follows
Note that after all, the Nordic NRF51822 board we have chosen is not a Mbed Ble Sensors Tag development board, so some onboard resources are slightly different, mainly GPIO configuration, ports such as UART, and the like. Therefore, simple modifications are required, and the modified source code is as follows, the highlighted part is the modified code.
The GPIO corresponding to the green LED light is P19, so it is necessary to modify here, otherwise the lamp will not be bright.
Next is compiling and downloading the HEX code file, click on the COMPILE of the menu bar, Mbed will compile the project file and download the corresponding code.
After successful compilation, the generated HEX file will be downloaded to the local computer.
Now use the MBED BLE SENSORS TAG to connect to the PC using the Micro USB, which will shoot a new mobile disk on the PC, and the drive letter on the author's computer is as follows
Below us, we can achieve code download / programming as long as we copy the generated HEX file to this mobile disk.
Download / programming functionality by copying
If you use Mbed for the first time, this process will be slightly complicated. Once you are familiar, you will feel convenient to develop by Mbed.
All is ready except for the opportunity. Know the Mbed, the following is the time when you really experience Ble Sensors tag!
Sensor development board recommended:
The Arduino Microsight Module The first chip size Arduino is compatible, allows you to use a built-in Arduino's OLED display that you want to use.
Boosterpack MKII Multi-Function Sensor Evaluation Board provides an analog handle, environmental and motion sensor, RGB LED, microphone, buzzer, a top show for a colorful LCD display.
PSOC-4 Drive Suite A sensor-based low-power consumption networked application design, available in termination, smart home, medical equipment, sports fitness monitoring, and other wearable smart devices.
Hardware experience
The BLE SENSORS TAG development board is very delicate, but it is in such a small space, it is hard to put into many peripherals. A single Bluetooth chip can only let you send and receive information, but if you have added peripherals and perform real communication with the outside, the effect is clearly different.
Below is a list of onboard resources
NRF51822 2.4GHz low power Bluetooth wireless SOC
Lis3DH low power 3 axis accelerometer
BMP180 temperature / air pressure sensor
1 x Mbed Programmer Powered by atsam3u2ca-au arm-based Flash MCU
8 x GPIO Pins
1 x UART Port
1 x Dual-color LED
2 x User Buttons
1 x buzzer
NRF51822
First make a brief understanding of NRF51822.
NRF51822 is based on ARM Cortex-M0, 16MHz, up to 256KB / 32KB (Flash / RAM) storage combination. Multi-protocol 2.4GHz RF transceiver has good benefits such as high performance, ultra low power and flexibility. Its main features include: in the low power mode of the Bluetooth is -92.5dB RX, up to + 4DBM output power; the link budget increased by 9.5dBm; lower than 10mA of peak current compared to NORDIC Suitable for 3V button batteries; compliant with Bluetooth low power (Bluetooth 4.0) standard; fully compatible with Nordic's existing NRF24L series IC air; supports non-parallel and parallel operations including Bluetooth low power consumption, ANT and dedicated 2.4GHz. Close-up
Hey, the solder paste on the chip is not washed?
BMP180 sensor experiment
BMP180 is a pressure sensor designated by Bosch. The air pressure measurement range is 300-1100 Bapa, using I2C bus and MCU communication, and also with temperature sensor function.
The connection between BMP180 and MCU is as follows
On the MBED's menu bar, click the import command, search for BMP180_example from the library, and import it into the Mbed in the project. According to the connection between BMP180 and MCU, the modified source file code is as follows.
Prepare a USB TTL debug line, take out the Swiss army knife PUTTY in the terminal, connect Ble Sensors Tag with the PC with the USB TTL line, and set the communication parameters in the PUTTY.
Download the HEX file to the Ble Sensors Tag board as follows in the PUTTY.
The front display is the air pressure data, and the temperature data is displayed later. However, so many scores, is the temperature so accurate?
Lis3DH experiment
The LIS3DH accelerometer chip of Semiconductor Company has a temperature sensor and three-way analog-to-digital converter that simply integrates the gyroscope or the like. Lis3DH can also achieve a variety of functions, including mice clicking / double-click identification, 4D / 6D direction detection, and saving sleep to wake-up mode. In sleep mode, the detection link remains active. When an event occurs, the sensor will wake up from the sleep mode to automatically improve the output data rate.
Lis3DH and MCU are connected by SPIPort communication, the schematic is as follows
New project MBED_LIS3DH, the method is to search for BLE_BASIC directly from the component library, then import it into the MBED environment, the complete code is as follows
Compile, copy to the local HEX file to the JLink virtual disk, and then see the three-axis number, the mobile development board, and the three-axis count value will change significantly in the PUTTY.
Lis3DH can be used to do a pedometer, falling to detection. The famous PEBBLE smart watch is built into the Lis3DH sensor.
Sensor development board recommended:
The Arduino Microsight Module The first chip size Arduino is compatible, allows you to use a built-in Arduino's OLED display that you want to use.
Boosterpack MKII Multi-Function Sensor Evaluation Board provides an analog handle, environmental and motion sensor, RGB LED, microphone, buzzer, a top show for a colorful LCD display.
PSOC-4 Drive Suite A sensor-based low-power consumption networked application design, available in termination, smart home, medical equipment, sports fitness monitoring, and other wearable smart devices.
Bluetooth communication experiment
The front two routines are used as onboard peripherals and communicate with the PC through the UART, and then truly experience Bluetooth communication.
This experiment simulates heartbeat detection, and transmits the results via Bluetooth to the mobile phone terminal, displaying the received heartbeat data on the mobile phone.
First, install Nordic official NRF Toolbox applications on your mobile phone, which is the official toolbox with Nordic, has a built-in test function.
According to the method described above, search for the BLE_HEARTRATE program in the library and import it into the Mbed, below is a complete engineering code file.
Compile and download it to the development board, open the mobile phone app, the screen is started as follows
After selecting the HRM function, the HRM detection interface will appear. Click Connect, App will scan the surrounding Bluetooth device, our Ble Sensors Tag will appear in the Available Devices list, as shown
The HRM1 here is the Bluetooth ID of the development board, and it will be connected to the development board.
After the mobile phone app is successfully connected to the development board, the heartbeat counter variable in the development board will be sent regularly to the mobile phone. The code is added or reduced by KEY1 and KEY2 to increase the number of heartbeats, and the actual data acquisition is simulated. The result of the information collected from the above chart displayed.
Three very practical experiments are also the technologies that have been used in many Bluetooth watches.
Here, you can't see some of the technical details encountered in the general MCU development: there is no clock tree, no GPIO registers, buttons, UART and other peripherals are abstracted, and in the object's instance initialization gives the most commonly used Parameters, peripherals are initialized! There is also the feeling of returning Arduino programming, yes, Mbed is to package, hide these details, give you the highest level, the most abstract API. Life is so beautiful, programming is so simple!
Is there an impulse to make a block Bluetooth watch? Is there a wood?
in conclusion
Mbed Ble Sensors TAG uses the currently commonly used NRF51822 as the master, providing Bluetooth communication functions, and also integrated a relatively practical sensor, such as BMP180, Lis3DH, and buzzers, etc., which are ideal for assessing wearable devices. Rounded PCB design, let people think of smart watch, in fact, onboard sensors, or even providing smart watches. Mbed support, abstract Detail of MCU development, high-rise API support, you can completely ignore the details of the underlying hardware, and experience the convenience of high-tech as you play Arduino.
Overall, Mbed Ble Sensors Tag, let us experience some of the principles and details of smart watch development, although this is not a full sense of smart watch, the veil has been unveiled, and mysteries are no longer.
However, there is no interface on the development board to introduce IDD detection, you can't feel the realization of low-power, very much, very much, very much, the convenience of the IDD interface on the STM32 development board.
Sensor development board recommended:
The Arduino Microsight Module The first chip size Arduino is compatible, allows you to use a built-in Arduino's OLED display that you want to use.
Boosterpack MKII Multi-Function Sensor Evaluation Board provides an analog handle, environmental and motion sensor, RGB LED, microphone, buzzer, a top show for a colorful LCD display.
PSOC-4 Drive Suite A sensor-based low-power consumption networked application design, available in termination, smart home, medical equipment, sports fitness monitoring, and other wearable smart devices.
More Bluetooth Development Kit Recommended:
Set NFC, WiFi, Bluetooth, FM function in one - Boyong BCM943341WCD1EVB evaluation board
Theoretical connection is actual, and the low-power Bluetooth program that has been seen together in these years
Green IoT, play is high - BLE development kit based on energy collected
Boyong BCM943364WCD1_EVB WICED WIFI Development Kit Review
Small-powered Bluetooth Development Kit - Cypress CY8CKIT-042-BLE evaluation
Objective network / wearable application - multi-sensor Numaker TRIO development board evaluation
Reference
Mbed IDE page
LINKSPRITE official website
MBED BLE SENSORS TAG Data Sheet
Mbed Ble Sensors Tag Official Wiki
Mbed Ble Sensors Tag Schematic
Mbed Ble Sensors TAG Downloader Schematic
Mbed Ble Sensors Tag Jlink-OB firmware
Original declaration: This article is originally created by the panel network, declined! "
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