Have you wondered how to build a internet connected smoke alarm using ESP8266 and a cheap Kidde RF-SM-DC? Overall idea is to detect smoke alarm signals and send MQTT message. Home Assistant reads the MQTT message and sends out notifications that can be used to notify your local fire station. ...
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/3.3V using 10k resistor ESP8266 is in OFF state, GPIO0 is low 3.3V signal arrives externally, GPIO0 and CH_PD are high, turn ON ESP8266 First thing ESP8266 does is turns GPIO0 to high, which means CH_PD remain high. So ESP8266 remains ON until GPIO0 is high GPIO12 is used to read value of external interupt If there is 3.3V external interrupt, GPIO is high and a MQTT message is sent as “Signal Received” or “ON” and keep ESP8266 ON until 0V signal is received. If there is 0V external interrupt, GPIO0 goes low and MQTT message is sent as “Signal Vanished” or “OFF” and turns OFF ESP8266 Software This project is built using ideas at http://www.esp8266.com/viewtopic.php?f=11&t=4458 ...
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. ...