How to use an ESP8266 on a WeMos D1 mini board to control a MAX7219 seven segment LED display and show a Youtube subscriber count over WiFi. Sketch and Schematic: https://github.com/GadgetReboot/Arduino/tree/master/ESP8266/YoutubeSubCounter_7Seg_WEMOS MAX7219 LedControl library usage https://playground.arduino.cc/Main/LedControl/ https://playground.arduino.cc/Main/LedControlDemos/ Modulo calculator with calculation explanations https://goodcalculators.com/modulo-calculator/ Previous subscriber counter video with more in depth details about getting/using a Youtube data API, Youtube channel ID, etc. https://youtu.be/rrxsMuR0Yko #MYYTC Patreon: https://www.patreon.com/gadgetreboot Pinterest: https://www.pinterest.ca/GadgetReboot Twitter: @GadgetReboot https://twitter.com/gadgetreboot ... https://www.youtube.com/watch?v=jj2YuwrD2OI

Here is one way to use a P channel MOSFET as a load switch to allow turning power on and off for another device electrically. I’m using a capacitive soil moisture sensor as an example of a circuit that may benefit from being controlled automatically, although there are other ways to get 5 V at a few milliamps to a sensor like that, such as powering it directly from a GPIO. But it is used here to demonstrate the operation of the FET switch. With the concepts working, larger current loads may be substituted for a more practical implementation of the concept. After getting the capacitive soil moisture sensor working with Arduino, seeing that it draws 5.5mA continuously, it would be good to be able to keep it powered off most of the time, since the soil moisture only requires infrequent readings. Using a FET to control the power for such a small load may be overkill - A GPIO rated more than 5.5 mA may work to power the sensor but inrush current may need to be considered because there is capacitance on the sensor power supply input. A small series resistor could help limit the slew rate with minimal voltage loss at 5.5 mA. Using the FET switch is more robust than a GPIO so it can at least prove useful in prototyping and if cost or space savings can be implemented later, the circuit can be put to use on higher power applications. Related videos on how the sensor works: https://youtu.be/pdGRs7GXBeE https://youtu.be/a-pqcmCr79I Sketch/Schematic: https://github.com/GadgetReboot/Arduino/tree/master/Uno/SSD1306_Soil_Meter FET and Load Switch app notes: http://www.onsemi.com/pub/Collateral/AND9093-D.PDF http://www.ti.com/lit/an/slva716/slva716.pdf https://en.wikipedia.org/wiki/MOSFET Patreon: https://www.patreon.com/gadgetreboot Pinterest: https://www.pinterest.ca/GadgetReboot Twitter: @GadgetReboot https://twitter.com/gadgetreboot ... https://www.youtube.com/watch?v=7sDIADAPdqI

I noticed my Early 2011 Macbook Pro track pad was no longer clickable and appeared to be pushing up through the case. I finally got the trackpad working again! CPU benchmark tool I used while diagnosing: https://software.intel.com/en-us/articles/intel-power-gadget-20 Patreon: https://www.patreon.com/gadgetreboot Pinterest: https://www.pinterest.ca/GadgetReboot Twitter: @GadgetReboot https://twitter.com/gadgetreboot ... https://www.youtube.com/watch?v=wGmYLRtgIm4

Using the Teensy 3.6 as a USB HID mouse and controlling the cursor with a 2 axis analog joystick module. Sketch: https://github.com/GadgetReboot/Arduino/tree/master/Teensy/USB_HID_Mouse Original Sketch: https://www.arduino.cc/en/Tutorial/JoystickMouseControl Teensy Arduino Plugin: https://www.pjrc.com/teensy/teensyduino.html Patreon: https://www.patreon.com/gadgetreboot Pinterest: https://www.pinterest.ca/GadgetReboot Twitter: @GadgetReboot https://twitter.com/gadgetreboot ... https://www.youtube.com/watch?v=TJDCOyQdrFk