Debashish Sahu

Extreme Power-Save Mode: ESP8266 Powered ON After External Interrupt

Have you ever wondered how to turn on ESP8266 using external interrupt? Build a battery powered amazon dash button or a 18650 lipo powered door bell using ESP8266 without putting the device in deep sleep? Here is your answer. Idea Keep ESP8266 on OFF mode as default External 3.3V signal (can be short or long) arrives and turns ON ESP8266 ESP8266 wakes up and keeps itself awake until a task is perfomed Send MQTT data to server Put ESP8266 back to power OFF state Implementation RST pin is always HIGH/3....

Internet Connected Dog Water Bowl Sensor

Wouldn’t it be nice to know if your dog’s water bowl is empty? Let us build a sensor that measures the water level every 5 minutes. This value is sent to MQTT server and Home Assistant automation takes care of the rest. This sensor connects to MQTT and Home Assistant. See dogsensor.yaml for adding this to HA. Assumes that one has set up various notification sensors available in HA....

MOSFET Used as Switch to Control a 12V Fan

Lets turn on and off low powered fan running at low (<20V) DC voltages. We shall use a MOSFET to achieve this. Hardware IRLML0030PBF ATTiny85 2-pin 12V Fan Wiring MOSFETs have three terminals Drain (D), Source (S) and Gate (G), where source is connected to ground and the +12V or +5V along with load (Fan) is connected to drain. The MOSFET is on when gate voltage is higher than 1....

How to Build a 3.3V Voltage Regulator

Here are the instructions to wire a stable AMS1117-3.3 voltage regulator properly. This can power an ESP8266 or any 3.3V micro-controller reliably supporting current draws up to 1A. Hardware AMS 1117-3.3 10 uF Electrolytic Capacitor 104 Ceramic Capacitor Wiring AMS1117-3.3 (right to left) Pin 1: GND Pin 2: Vout Pin 3: Vin Connections 5-12V -> Vin GND -> GND 10 uF Electrolytic Capacitor +ve -> Vout 10 uF Electrolytic Capacitor GND -> GND 104 Ceramic Capacitor +ve -> Vin 104 Ceramic Capacitor GND -> GND

IoT Dot Matrix Display: Twitter Mentions Using ESP8266 Adafruit.io and IFTTT

Let’s say that you don’t have your smartphone around and someone mentions you on twitter. Wouldn’t it be nice to have a display that automatically reads your twitter mentions and show it on a scrolling display? So let’s build a internet controlled (IoT) dot-matrix display that does this for us using an ESP8266. The plan to accomplish this is as follows: Someone mentions us on twitter (in my case @debsahu) IF This Then That (IFTTT) tracks these mentions and posts this data on Adafruit....