Smart Garden Management System with Sensor Network

Transcription

1 Smart Garden Management System with Sensor Network Project Proposal Team 74 Yen- Lin Liu, Chun- Lin Chao TA: Benjamin Eng February 7, 2016 ECE 445 1

2 Content 1. Introduction Statement of purpose Objectives Goals Functions Benefits Design Block Diagram Block Description Node Gateway Requirements and Verification Table of Requirements and Verification Tolerance Analysis Cost And Schedule: Cost Labor Parts (By Grove) Total Cost Schedule

3 1. Introduction 1.1. Statement of purpose People often grow unsuitable plants in their gardens so that they usually die from the lack of proper nutrients, suitable ph, enough water, or even too much sunlight. We want to solve this problem, so we decided to build a system that can monitor the environment and give user recommendations on what plants to grow. Currently there are some solutions like Edyn. It is also an environmental sensing system; however, it only provides single point sensing and it connects to Wi- Fi, which is impossible to be reachable in the whole garden. We plan to make a system that provides multi- point sensing and builds its own network instead of totally relying on existing network Objectives Goals - Build a sensor network to detect environment parameters in a medium size garden (100x100 at most). - Give advices on what to plant in each section of the garden. - Reduce plants death from improper environment Functions - Obtain temperature, moisture, humidity, and light values from a sensor array. - Show the overall status obtained on a map. - Give recommendations on planting the garden. 3

4 Benefits - Cheap and easy to build - Light weight - Easily scalable - Remote monitoring - Real- time alert 2. Design 2.1. Block Diagram There are two sets of hardware in our system. One of them is the sensor node as Figure 1 shows, the other is the gateway, as Figure 2 shows. Figure 1 4

5 Figure Block Description Node Sensor Array For each array, we will put in temperature, moisture, and humidity sensor. Each of them will output raw analog data to the MCU. We will also design a light sensor by ourselves, since current light sensors we found has a very limited resolution range. We will build a circuit to switch between different components to obtain better resolution MCU We will use simple Arduino UNO as our primary MCU in a node. It will receive raw data from the sensors and pass them onto the communication network. 5

6 Power Supply We will use rechargeable button cells (LIR2450) as battery and construct our own PCB to supply all the requiring voltage of the circuit. It provides volts, so we will need a step- up converter to provide the voltage we needed. We will also construct a USB recharging circuit to charge the battery As for the MCU, it requires 7-12V to operate; the sensors mostly require 5V or 3.3V to operate. So we have to build a circuit to supply at least 3 kinds of output voltage Communication Module We are mainly using ZigBee as our communication protocol and we choose XBee module to be the actual chip. We choose ZigBee for reasons as follows. First, ZigBee is more suitable for constructing a light- weight network rather than Bluetooth or Wi- Fi. Bluetooth transmissions require pairing, but only up to 7 devices are allowed to be active at the same time. Wi- Fi requires extra hardware like routers, but it is not always possible to have Wi- Fi routers placed around the whole garden. ZigBee allows up to 255 devices active on the network, so it best out all three. Second, the cost of constructing a network using ZigBee is the lowest among all three methods. Bluetooth and Wi- Fi require much more power than ZigBee does. Wi- Fi also requires extra hardware like we mentioned above. ZigBee only requires an antenna on each chip to construct the network, so is then cheaper than the others Gateway The gateway obtains sensor data from the ZigBee network 6

7 by XBee module and post them on the Internet through Wi- Fi. As a result, we choose to use LinkIt ONE instead of Arduino as the MCU since it has built in Wi- Fi module. An external Wi- Fi router will be needed here in order to connect to the Internet. 3. Requirements and Verification 3.1. Table of Requirements and Verification We will discuss the sensors and the rest of hardware components separately. Requirement Verification Temperature sensor 1.Error ± 1 C 2.Working Voltage(V CC ): 3.3-6V 3.Output voltage: 0- V CC 4.Output current: 1-1.5mA Temperature sensor (a)hold a thermometer next to the sensor to verify the value (b)ensure the error between thermometer and the sensor remains within ± 1 C 2.Verification Process for Item 2 (a)attach the voltage supply to Vin (b)attach voltmeter to the input pin (c)set voltage of the power supply and ensure the working voltage is between 3.3~6V 3.Verification Process for Item 3 (a)short leads to simulate lower temperature (b)attach voltmeter to the output pin (c)set voltage of the power supply to the working voltage (d)ensure the output is 0V (e)remove the power supply 7

8 (f)remove short to simulate higher temperature (g) Attach the power supply and set voltage to V CC (h)ensure the output is V CC Humidity sensor 1.Error ±5% 2.Working Voltage(V CC ): 3.3-6V 3.Output voltage: 0- V CC 4.Output current: 1-1.5mA 4.Verification Process for Item 4 (a)attach the current meter to the output pin (b)ensure the output current is between 1 ma and 1.5mA Humidity sensor (a)hold a humidity meter next to the sensor to verify the value (b)ensure the error between the meter and the sensor remains within ± 5 % 2.Verification Process for Item 2 (a)attach the voltage supply to Vin (b)attach voltmeter to the input pin (c)set voltage of the power supply and ensure the working voltage is between 3.3~6V 3.Verification Process for Item 3 (a)short leads to simulate lower humidity (b)attach voltmeter to the output pin (c)set voltage of the power supply to the working voltage (d)ensure the output is 0V (e)remove the power supply (f)remove short to simulate higher humidity 8

9 (g) Attach the power supply and set voltage to V CC (h)ensure the output is V CC Moisture sensor 1.Error ±5% 2.Working Voltage(V CC ): 3.3-5V 3.Output voltage: 0- V CC 4.Output current: 0-35mA 4.Verification Process for Item 4 (a)attach the current meter to the output pin (b)ensure the output current is between 1 ma and 1.5mA Moisture sensor (a)put a moisture meter into the soil to verify the value (b)ensure the error between the meter and the sensor remains within - 5% and 5 % 2.Verification Process for Item 2 (a)attach the voltage supply to Vin (b)attach voltmeter to the input pin (c)set voltage of the power supply and ensure the working voltage is between 3.3~5V 3.Verification Process for Item 3 (a)short leads to simulate saturated soil (b)attach voltmeter to the output pin (c)set voltage of the power supply to the working voltage (d)ensure the output is 0V (e)remove the power supply (f)remove short to simulate arid soil (g) Attach the power supply and set voltage to V CC 9

10 (h)ensure the output is V CC Light sensor 1.Error ±5% 4.Verification Process for Item 4 (a)attach the current meter to the output pin (b)ensure the output current is between 0 ma and 35mA Light sensor (a)hold a light meter next to the sensor to verify the value (b)ensure the error between the meter and the sensor remains within - 5% and 5 % Requirement MCU 1.Operate between - 20 C to 30 C for at least a week. 2.I/O correctly with 0-5V Power Supply 1.Able to drive different sensors, ZigBee, Wi- Fi and MCU 2.Provide at least 9V, 5V, 3.3V output with ±10% error. Verification MCU (a)place the nodes in action for a week outdoors and indoors to check if it s working fine 2.Verification Process for Item 2 (a)attach voltmeter to the input and output pin (b)ensure input and output voltage remains within 0 V and 5 V Power Supply (a)test the supply after working for few days to see if it s working fine 2.Verification Process for Item 2 (a)use digital multi- meter to measure the voltage of different output nodes (b)ensure the error remains within 10% 10

11 ZigBee 1.ZigBee modules should transmit at least 2 sets of data through the network per minute, within 50 meters without any data lost. ZigBee (a)transmit data through different distance (b)place objects that may appear in garden between sensors such as flowers and verify the result 3.2. Tolerance Analysis As for our project, there are several components that is critical to the system. First is the ZigBee network, the stability of ZigBee directly depends on the obstacles in the environment. To verify this, we have to establish a ZigBee network first, and then add any potential obstacles or noise to test its stability. As the requirements stated above, we will have to transmit data through 50 meters, and the theoretic maximum transmit distance is 100 meters, so it should be in the safe zone. More over, there are up to 4 sensors in our present design; each will be at most a floating- point number, so a set of data will be at most 16B. ZigBee has maximum transmit speed 31.25B/s, which should be more than enough to transmit 2 sets of data in a minute. 11

12 4. Cost And Schedule: 4.1. Cost Labor Name Hourly Rate Total hour Total = Rate * 2.5 * Total hour Yen- Lin Liu $ $5600 Chun- Lin Chao $ $5600 Subtotal $ Parts (By Grove) Name Quantity Cost Temp & Humidity 4 $46 Sensor DHT22 Moisture Sensor 4 $20 SEN92355P XBee module 4 $107.8 Wi- Fi Shield 1 $59 Arduino UNO 4 $ Total Cost Total = Labor + Parts = $

13 4.2. Schedule Date Yen- Lin Liu Chun- Lin Chao 2/8 Prepare project proposal and research on components 2/15 Test ZigBee/Wi- Fi Finalize Design Review transmission 2/22 Design PCB Design power supply 2/29 Construct all the sensor in a box 3/7 Design simple user interface Design and order the circuit 3/14 Assemble all parts, debug and test the device 3/21 Spring Break 3/28 Assemble all parts, debug and test the device 4/4 Prepare for mock demo 4/11 Debug the project after Begin the final paper mock demo 4/18 Prepare for final demo Prepare for final paper 4/25 Finalize the presentation and demonstration 5/2 Finalize the final paper 13