The DS3231 Real-Time Clock (RTC) Module is one of the most popular and reliable time-keeping solutions for Arduino, Raspberry Pi, and other microcontroller projects. Unlike simpler RTC chips such as the DS1307, the DS3231 features a built-in temperature-compensated crystal oscillator (TC…
The DS3231 Real-Time Clock (RTC) Module is one of the most popular and reliable time-keeping solutions for Arduino, Raspberry Pi, and other microcontroller projects. Unlike simpler RTC chips such as the DS1307, the DS3231 features a built-in temper…
Here, I demonstrate how to build a high-precision digital clock and thermometer using the DS3232 Real-Time Clock (RTC) and a 0.91-inch I2C OLED display. This project is a perfect upgrade for any embedded system that requires accurate timekeeping and…
Yesterday, I wrote briefly on a circuit which allows one to send or communicate audio using light as the communication channel. In that circuit only the NE555 Timer with the sine wave signal as input audio was used for purpose of testing. Here, I w…
Transistor biasing is fundamental skill one must master in electronics circuit design. Given that you have an electret microphone and want to output the microphone audio into a $8 \Omega$ speaker, how would you do that? There are many ways and one…
In my previous blog post on designing light communication receiver circuit using pulse frequency modulation (PFM) technique, I said that because of noise in the output signal I had to use unity gain Sallen-key 2nd order filter. And after the filte…
While designing the receiver for PFM (Pulse Frequency Modulation) circuit, the output signal was distorted with high frequency carrier signal. The transmitter used frequency of 25KHz and that was riding on the input message signal. After troubleshoo…
