Circuit for regulated power supply required for the project is shown in Fig. 2. It is built around 12V-0-12V, 750mA step-down centre-tapped transformer, full-wave rectifier comprising two 1N4007 diodes (D1 and D2), 5V regulator 7805 (IC1), and two electrolytic capacitors: 1000µF, 25V (C1) and 100μF, 25V (C2).
The main circuit, shown in Fig. 3, is built around soil moisture sensor module DHT11, STM32F103 board known as Blue Pill, LM016L LCD, ESP8266 board, and a few other components. The power requirement of this project is 5V for STM32 and 3.3V 3.6V for ESP8266 Wi-Fi module.
5V is converted to 3.6V through the potential divider circuit formed by silicon diodes D3 and D4 and the 1k resistor connected in series with them. Each silicon diode's cut in voltage is 0.7V. So, the two diodes in series drop the voltage by 1.4V and we get 5V-1.4V = 3.6V.
As shown in Fig. 3, the DHT11 sensor is used to measure temperature and humidity. The sensor comes with a dedicated in-built NTC thermistor to measure temperature. It has an 8-bit microcontroller on-board to output the values of temperature and humidity as serial data through one-wire protocol. The sensor has only one data pin through which both temperature and humidity values can be read, thus saving pins on the microcontroller side. The sensor is factory calibrated and easily interfaces with a microcontroller. Pin details of DHT11 are shown in Fig. 4 and the STM32F103C8T6 (Blue Pill) is shown in Fig. 5.
Voltage regulator for STM32 can be replace by 5V battery or 5V DC adaptor. The STM microcontroller is used for getting the sensor data and displaying it on LCD and also sending the data to the Wi-Fi board. The ESP receives the data and uploads it to ThingSpeak cloud. But before that we need to set up the ThingSpeak and get the API token to incorporate it in the code.
Bu hikaye Electronics For You dergisinin January 2023 sayısından alınmıştır.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber ? Giriş Yap
Bu hikaye Electronics For You dergisinin January 2023 sayısından alınmıştır.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber? Giriş Yap
Smart WATER SERVING ROBOT
With the advent of artificial intelligence, robots find application in various sectors such as industry, homes, bars, restaurants, events, agriculture, and even space.
Multi-Purpose Wire-Loop SECURITY SYSTEM
This multi-purpose security system utilises wire loops to secure items. Wire loops can be employed in various ways for security applications such as luggage security, bike security, bicycle security, room security, and door security.
The Importance Of RADIATION PATTERN OF AN ANTENNA
Look beyond an antenna’s size and gain; its radiation pattern holds the key to its performance. Understanding this can unlock a whole new perspective on wireless communication
"Capitalise On 'CHINA PLUS TWO,' Where Products With Higher Value Addition BECOME THE FOCUS"
EPIC Foundation aims to transform India into an electronics hardware product nation by collaborating with governments, universities, design houses, and startups.
ADDING LOCATION TRACKING To The Wearable Interface Device
Here’s how you can add location tracking, without GPS, to the project for a smartwatch like HID with keyboard and touchpad, which was published in March issue.
"NATUREINSPIRED ADAS ALGOS Will Be MUCH BETTER Than Robotic Paradigm Algos"
Most of the ADASenabled vehicles of today function on algorithms (algos) inspired by robots used in a logistics setup. Can ADAS algos inspired by the human brain and nature be better? In a conversation with EFY's Mukul Yudhveer Singh, Gagandeep Reehal, Co-Founder, CEO & CTO, Minus Zero, illustrates this using the 'sunset mistaken for red light' example, shedding light on where India's Minus Zero is headed!
NEW EV POLICY: Will It Kill More Than Two Birds With One Stone?
With China taking the lead in electric vehicle production and sales in many global markets, can India’s new electric vehicle manufacturing policy encourage champion brands to set up shop in India? Can this policy be the turning point for India’s automobile industry’s bid to go global?
A Device That Enables SELLING UNUSED INTERNET DATA From Your Mobile Network
What if you could sell your remaining mobile data before the end of the month or even daily? Christophe Bureau, a Board Member of DotDot, in a conversation with EFY’s Mukul Yudhveer Singh, sheds light on what the Dot device offers beyond assisting users in selling their unused internet data
"EV INDUSTRY'S In The Compounding Stage Of BATTERY CELL TECHNOLOGY"
As sodium-ion battery packs gain attention in India, does this spell a bleak future for lithium-ion batteries? Furthermore, where does hydrogen stand as a fuel cell and combustion fuel? Dr Yashodhan Pramod Gokhale, CTO of Battrix, weighs in
ASSISTIVE AI: Semiconductor Design, Manufacture, And Workforce
Together, human intelligence and AI create a powerful synergy, highlighting the vital lesson for the semiconductor workforce: adapt to new technologies