Week Two (Jan 15th - Jan 20th)

During this week, we have tested the new parts that arrived. The following list shows the parts that we tested:

1. Temperature Sensor (KY-015)

2. Wi-Fi Module ESP8266 Development Board

3. Water Flow Sensor (YF-S201B)

---

1. Temperature Sensor (KY-015)

The sensor came out with three different pins: positive, out, and negative. The Arduino Uno R3 was used to test this sensor. We have created a simple code that shows the room temperature and humidity. The values are shown in the "Serial Monitor" found in the Arduino IDE. Also, it is important to mention that the value for temperature is in Celsius and the value of humidity is in percentage. Below can be found an screenshot of the results at the moment of the test and a digital picture of the circuit.

Image created by open-source software called Fritzing

---

2. Wi-Fi Module ESP8266 Development Board

During our proposal, we mentioned that we were going to use a Wi-Fi Module ESP8266. However, we have come with a better version of it which does the same function, but it can be programmed. The idea of using trying to use this Development Board is to avoid the usage of Arduino for our trays so that we can lowered the cost of the project. With this board, we would be able to connect the Soil Sensor to it and send data to our main Arduino, which will be located at the bottom of the system.

This board can be used with the Arduino IDE by doing some configurations and adding some libraries. However, after we did our research we came across a warning: the board can only take 3.3V for I/O peripherals. To solve this case we have created a circuit using voltage divider that will convert 5V into 3.3V.

Unfortunately, we did not expect this and we will need to wait until next Monday (Jan 22nd) to test it out in the Open Lab at Valencia College. Once we tested, we will update the blog with the formulas and resistors values.

---

3. Water Flow Sensor (YF-S201B)

One of the main approaches that we are planning to use in order to keep track of the functionality of the system as well as the efficiency of it is by controlling the water that is being used daily, weekly, or monthly. For that, we have acquired a water flow sensor that can be used with Arduino.

The challenge that we might encounter during this process is to control the pressure of the water. According to the datasheet of the sensor, it can only take up to 2 MPa (MegaPascal, unit used to measure the pressure. 1 Pascal = 1 NW^2). Another reason for putting an eye on the water pressure is because the UV diode light for the filtration system will require a certain amount of pressure in order to get the best filtration.

For this week, we are going to dig the internet to pull any information we need to know of this sensor before we connect it to the Arduino to avoid any damages.

For next week, we are planning to upload a video of us testing the water flow sensor and showing the values that are coming out of it.

So far, we have found that the sensor work with voltage pulses and the water flow can be calculated by using the following formula:

Pulse frequency (Hz) / 7.5 = flow rate in L/min.

---

REAL PARTS PICTURE