This is another ESP32 with RTC and LED matrix project. This time I have put a ping pong visualization just for fun.
Continue reading “Digital clock with ESP32 RTC and LED Matrix”
Passion in Electronics
This is another ESP32 with RTC and LED matrix project. This time I have put a ping pong visualization just for fun.
Continue reading “Digital clock with ESP32 RTC and LED Matrix”
Here’s another project using ESP32 with RTC and LED Video wall module. It is basically same with the last project with analog clock
Continue reading “Digital clock ESP32 with RTC and LED matrix”A power sequencer is useful for audio systems where you can power up each equipment one at a time in sequence. This will prevent pop sound on the speaker during powering up or down. Basically the power sequence is from input to output when powering up and output to input when powering down.\
Continue reading “Power sequencer using arduino nano”
I recently got to work with 64×64 RGB matrix and got into some issue. For some reason it only displays half of the screen. After some research, I figured it is just a simple problem.
Continue reading “64×64 RGB matrix half screen issue”Currently I am working with a automatic transfer switch for solar power and I needed something to detect if there is an AC voltage output of the power inverter and the Distribution utility.
Continue reading “High Voltage AC detector for Arduino”
One of the problem for low budget band online streaming is the mixing part. The biggest challenge is getting the mix right. Why is it hard? Guitar and other instruments have their own amplifier so when you are doing the mix, you would likely decrease the level of these instruments to the main mix. If you are feeding the main mix into your online live feed, chances are these instruments are too silent on the main mix.
This circuit can be use as a headphone amp mixer with built in DI box so you can directly feed the output into the mixer. There are 2 volume knobs, one knob is used for your instrument volume and the other knob can be used as a monitor level feed from the mixer.
Continue reading “Monitor Mixer with DI Box”Here is a simple circuit that have 7 band spectrum analyzer, bass mid treble and volume controls and input selector. This TDA7419 project is intended for bluetooth speaker project.


Here is a simple circuit that I made to charge my 14.4V 4s LifePo4 battery with solar power. MPPT stands for Maximum Power Point Tracking. In a normal PWM solar charge controller, it is basically just a switch which turns on and off when the battery is full, the problem with this is the solar panel voltage drops near the battery voltage hence dropping the output power. With MPPT, it will allow the solar panel at maximum power with the maximum voltage.
Continue reading “60W MPPT Solar Charger for 14.4V LifePo4”In case you are looking to make a Buck controller based on arduino, this is a simple circuit to drive the PMOS transistor mainly for buck circuit applications.

This circuit is simple and only consist of NPN and 1 PNP transistor. The circuit above is part of my MPPT solar charger circuit.
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Here is a simple stereo headphone mixer that can be used for monitoring and mixing 2 sources. A very helpful device for online streaming. How? For example you are playing a keyboard on a band in an online stream and using a headphone as monitor. You can use this to mix the headphone output of you keyboard and headphone output of the streaming mixer so you can hear more of your keyboard.
Continue reading “4Ch Mini Stereo Headphone Mixer”