"With the continuous breakthrough of Internet of things applications, we can more and more feel the convenience brought by IOT in real life. For example, the relatively advanced building automation lighting, through various sensors such as infrared monitoring or sound monitoring, will automatically trigger lighting once an event is sensed. Such functions are everywhere in the building, Then the monitoring and control are realized through the wireless network, which has become a very popular building automatic lighting control. The problem we need to deal with is how to make the wireless network achieve high communication quality in the complex environment of the building. In view of this situation, ADI has launched a complete set of wireless sensor node (WSN) solution based on sub GHz technology - ev-adrn-wsn-1z. By deploying low-power sensors and other measurement systems, ADI can wirelessly realize data acquisition and control in various complex environments, thus greatly enhancing automatic management, monitoring and maintenance.
At present, there are two versions of ADI's wireless sensor network development kit, the branch version and the cluster version. The biggest difference between them lies in the difference of wireless communication control system: (click here to buy this development board on ADI's official website)
Bundle version: ADI Aducrf101 wireless single chip solution (integrated TRX + arm cortex m3 MCU)
Cluster version: ADI adf7024 sub GHz ISM band transceiver + Renesas 16 bit MCU (rl78-g13) is adopted
EV-ADRN-WSN-1Z
This time, Aiban has obtained the ADI bundle version of the wireless sensor network development kit. The specific model is ev-adrn-wsn-1z. Let's have a look.
The kit includes a mesh joint board ev-aducrf101mkxz, two multi-sensor node boards ev-bunch-wsn, a simulation debugger and some accessories around the development kit: antenna, MINIUSB cable and 4GB data USB flash disk. Among them, as like as two peas, the hardware of the two sensor nodes is exactly the same. The only difference is that when the factory is fired, different firmware is burned. From the official website data, a sensor board mainly transfers data of three axis accelerometers, and the other transfers data of temperature and humidity.
The working principle of the whole development kit is to collect the data from the sensor node board through the network node board to realize the integration of information data. The main way of data transmission is realized through ADI's wireless single-chip solution aducrf101. Let's look at the characteristics of the network node board and multi-sensor node board in this kit.
EV-ADuCRF101MKxZ
Ev-aducrf101mkxz is a very simple board of hardware system, which can be said to be the smallest system board based on ADI aducrf101 wireless single chip.
The board is equipped with a 6pin programmable debugging interface and an SMA antenna RF interface. The 6pin debugging interface realizes the board power supply and programming through the simulation debugger in the connection kit. The SMA RF antenna interface can directly connect the antenna in the kit, as shown in the figure below.
In addition, the spare IO pins of aducrf101 chip are extended on both sides of the board, which is convenient for engineers to expand DIY according to their own needs. The whole design is very considerate（ (next page)
ADI sensor development board recommendations:
Adxl346z-s Evaluation Kit A small and thin ultra-low power 3-axis accelerometer is very suitable for mobile device applications and can provide a variety of accelerometer sensors with special detection functions.
Adxl001-500 evaluation board This accelerometer sensor is very suitable for mechanical, medical and military applications that need wide bandwidth, small size, low power consumption and reliability.
Adxl001-250z evaluation board An accelerometer sensor that can accurately detect motion and is an industry-leading accelerometer sensor in terms of power, noise, bandwidth and temperature specifications.
ADuCRF101
Thanks to the high integration of aducrf101, the realization of the function of the board wireless system only requires a small number of electronic components outside the chip, which greatly reduces the difficulty of engineers in circuit design. What functions are integrated inside aducrf101?
Main features of aducrf101:
Arm coretx-m3 processor, integrated with 128KB flash and 16kb SRAM
Integrated RF transceiver, wireless band: 862 MHz to 928 MHz, 431 MHz to 464 MHz
RF receiving sensitivity: − 107.5 DBM at 38.4 kbps
6-channel 12 bit SAR ADC, sampling rate 167ksps
Power consumption: Rx: 12.8ma, TX: 9 ~ 32mA, 280na off mode
Support many peripheral interfaces, such as UAR, I2C, SPI I / O
Package: 64 lead, 9 mm × 9 mm LFCSP
From the hardware system block diagram, adurf101 chip integrates arm Cortex-M3 processor, sub GHz radio frequency part, analog ADC part, timer, IO port and other peripheral resources. It can be said that the chip itself is a very complete wireless communication control system The integration of microcontrollers greatly reduces the difficulty of engineers in circuit design, but at the same time, this integration is also a great test for the performance of the chip itself, but it is still very worthy of expectation from the data given on the official website.
However, seeing this, some people may wonder, what is sub GHz wireless technology? What is the difference between this and the WiFi and low-power Bluetooth technologies we often contact?
In wireless communication, the frequency band is usually less than 1GHz, which we call "sub GHz", and this technology has existed for many years. This wireless technology is more suitable for applications with long transmission distance, low power consumption, low data rate and less data transmission. Due to its larger coverage and stronger broadcasting capacity, it will often become the first choice for industrial and commercial applications, For example, building automation mentioned at the beginning of our article clearly meets the needs of this field more than the wireless systems using 2.4 GHz band such as Wi Fi, Bluetooth and ZigBee we often see. Refer to the following table for specific characteristics.
EV-BUNCH-WSN
In addition, let's take a look at the multi-sensor node board ev-bunch-wsn. Because the hardware of the two boards in the kit is the same, choose one of them here. As shown in the figure below, the main control and communication part of ev-bunch-wsn board also adopts ADI The solution of adurf101 wireless single chip will not be repeated here. From the naming of multi-sensor node board, it is not difficult to speculate that ev-bunch-wsn board must be equipped with many sensors. What are they?
Onboard sensor:
Triaxial accelerometer: adxl362bccz
Digital temperature and humidity sensor: SHT21
Ambient brightness sensor: apds-9005
Digital temperature sensor: adt75armz
PIR motion detection sensor (not pasted)
From the sensors carried on the board, careful friends will find that they have something in common. They all belong to ADI's own products. As we all know, sensors are an important part of IOT, intelligent hardware and so on. In this era of rapid take-off of the Internet of things, ADI is gradually expanding its product line in this field, Accordingly, we can also see more corresponding products in the future.
In addition to carrying a large number of sensors, ev-bunch-wsn board interfaces are also very rich. It is a great challenge for engineers who first contact this board to be familiar with the functions of these interfaces. How to operate the specific functions of each interface will be introduced in detail during power on. In addition, we can also see from the back of the board that the multi-sensor node board can be powered by a 3.3V button battery（ (next page)
ADI technical recommendations:
E-books just launched -- collection of solutions and reference circuits
ADI basic course summary
Why is serial interface faster than parallel interface?
Power on use
Ev-adrn-wsn-1z development kit is a product that can be used out of the box. The boards and cards have burned the factory procedures. We can complete the small experiment of wireless data acquisition only by following the steps in the instruction manual. Of course, we need to make some preparations before the experimental demonstration.
First, we need to install a software named anodecenterpoint. Through this software, we can intuitively observe and analyze the data transmitted from the sensor node board to the gateway board. The software can be found in the start here folder under the USB flash disk provided by ADI. In fact, in addition to some tools and software in the experiment, the USB flash disk provided by Adi also comes with a wealth of data documents, including battery estimation tools, data manual, hardware schematic diagram, video tutorial, use guidance, etc., which completely saves the time for engineers to collect data when they first contact the product（ If users need the latest information or software, it is recommended to download it from ADI's official website.)
After the ev-aducrf101mkxz gateway board is powered on, we can find the corresponding device through find devices in anodecenterpoint software.
The protocol stack version and ISM frequency band (868mhz) are displayed in the device details.
To transmit the data of the sensor node board to the gateway board, first supply power to the sensor node board. In other words, there are many "patterns" of power supply in this part. First, it includes three kinds of power supply, namely CR2032 button battery power supply, USB signal power supply and energy harvesting interface power supply. The descriptions of several interfaces of power supply are shown in the figure below.
It should be noted that USB power supply does not mean that the board card is equipped with a USB interface to supply power directly, but through the USB power signal line. In practice, it is still necessary to connect 5V power supply through DuPont line or other connecting lines. Among the three power supply modes, CR2032 button battery and energy harvesting interface are respectively set to whether to supply power through on-board LDO (adp160aujz-2.7, 2.7V output). The specific operation modes will not be explained one by one here. You can refer to the user's instruction manual. 5V USB cable power supply has no such setting because it must be output through LDO step-down, Otherwise, it exceeds the withstand voltage value of the on-board chip.
From this common power supply circuit, we also found that the ADI power supply design was considered very carefully at the beginning, so that engineers can evaluate the performance of actual products for different power supplies. Next, the author selects the simplest power supply mode, which is directly powered by the on-board button battery (no longer through LDO), and directly closes the jump cap at position C on LK2.
At the moment when the jump cap is closed at LK2 C position, you can see the power LED flashing. After the sensor node board is powered on, the gateway board will collect data from the sensor node board. We can see the most intuitive display from anodecenterpoint software, as shown in the following figure（ (next page)
ADI technical recommendations:
Key recommendations, see which one has entered your design list
Do you want to be a great master?
The most popular technical articles are all dry goods!
Power on another sensor board in the same way. At this time, you can see the data sent by two different devices in the software.
In the Network Overview tab of anodecenterpoint software, you can see that visual values from triaxial accelerometer and hygrometer are received respectively.
The performance of wireless signal quality can be seen in the node performance. The following figure shows the performance of the two devices when they are very close. We can see that the RF quality is very good. The RSSI is - 49dbm. As the author moves the sensor node board to a further place for testing, the RSSI will decline. However, in the testing of the author's whole company, When the signal is the worst, it is about - 70dBm (well, forgive us that our company is not big enough).
In addition, we can also reconfigure RF parameters through anodconfig application.
Experienced engineers can customize RF frequency and transmission rate according to product requirements. This paper will not introduce them one by one. However, it should be noted that anodecenterpoint and anodeconfig cannot be used at the same time.
In general, ADI ev-adrn-wsn-1z is an easy-to-use wireless sensor network development kit. Although the sensors on the multi-sensor node board ev-bunch-wsn are limited, the interface of the network node board ev-aducrf101mkxz is relatively flexible, and the outgoing IO port allows engineers to expand more sensor types, It can effectively help engineers develop practical systems conveniently; Moreover, in terms of power consumption that engineers are very concerned about, the ADI carried by the board The aducrf101 wireless single chip solution can maintain the power consumption levels of Rx: 12.8ma and TX: 9 ~ 32mA. In addition, different low-power modes can last for several years even if one battery is powered (the ADI CD provides a power estimation tool for wireless systems. Interested friends can test it in person and download the address). For those who want to know about sensors For engineers who want to use sub GHz wireless technology to do some low-power applications, ADI's Wireless Sensor Network Suite is a rare and considerate development tool.
Summary
This paper introduces the latest wireless sensor network development kit ev-adrn-wsn-1z launched by ADI. The kit mainly includes an ev-aducrf101mkxz network node board and two sensor node boards ev-bunch-wsn. The observation and analysis of sensor data are realized through sub GHz wireless technology. The board is equipped with ADI core single-chip wireless solution aducrf101 (which internally integrates arm Cortex-M3 processor, sub GHz wireless RF part, analog ADC and other peripheral resources), triaxial accelerometer, ambient brightness sensor, digital temperature and humidity sensor, digital temperature sensor and other resources. In addition, ev-adrn-wsn-1z also supports multiple mainstream industrial field wireless protocol stacks, For example, 6LoWPAN, adradionet, wmbus and wisun have always been the short board of domestic customers. The full set of data provided by Adi is very important for us
Our other product:
