Meet Powah, a little power on/off toggle with an indicator LED. It uses a pair of Schmitt triggered inverters to debounce the button, and a P-channel MOSFET to switch the power on and off. The board is designed to be plugged into a breadboard. It is designed to mount on one end of my breadboard, […]
Power toggle switch with an indicator LED Read More »
Seven segment LED displays and discussed about a time-division multiplexing technique that reduces the number of required microcontroller I/O pins to drive multiple seven segment LED displays. Today we will move a step further and discuss about a serial interface (SPI) for driving 8 seven segment LED displays. The technique uses MAXIM’s MAX7219 LED driver
Netduino and MAX721 interfacing for driving seven segment LED displays Read More »
One of the basic usage of the TIMER peripheral on every microcontroller is to provide the accurate timing mechanism. Using the TIMER peripheral as the basic timing, we could easily develop a stopwatch and display it to the 8-Digit seven segment numeric LED display. Thanks to the Maxim MAX7219 chip which enable us to interface
Build 8-Digit LED Display stopwatch using Maxim MAX7219 Serially Interfaced Read More »
Most commercial LED flashlights use three AAA or AA batteries in series that produce 4.5V. The batteries then drive four white LEDs that connect in parallel. These LEDs can work at voltages as low as 2.7V and, in some cases, 2.4V. At those voltages, the LEDs become dim, and you must frequently change the batteries.
LED-flashlight circuit works at 0.5V low voltages Read More »
