Reddit:Electronics

Hi !! Im happy to share my latest project. It's an ESP32-based board crafted for flexible projects, featuring an IMU, ADCs, XBee socket, RTC, Buzzer, Li-ion battery charger (1.5A) and monitor, general-purpose IOs, pushbuttons, RGB LEDs, SD card slot, Qwiic connectors, ambient temperature, humidity, pressure sensors, and USB programming capability! Almost completely SMT.

The PCB is a 4-layer design that I personally assembled <3

https://preview.redd.it/svxw5hlczxlc1.png?width=4000&format=png&auto=webp&s=e54bd89516de9d19a2950ca8faae45d8c4ab28cc

So i made a color sensor/detector without microcontroller (I don't like doing it the easier way ) the method is pretty easy when we want to detect the color red for example, we need red led and ldr when the red led turn on the resistance of ldr will decrease, the trick is when red object is infrot of red led and ldr it will reflect more light because red objects don't absorb the red color so it reflects it to the ldr and produces more light which will make the resistance become more lower and if we use another color green for example it won't affect the ldr resistance because the color green absorb the red light, to detect the changes of the resistance of ldr we are gonna use op amp as compartor, every color in the world is just the mix of red-green-blue so I'm going to use rgb led but you need to power them in order and not at the same time so I'm gonna use 4017 ic and ne555 timer as clock for it we need 3 pins at least so we need stop the clock when it pass the the blue pin I'm giong to use not gate (more detail in the pdf) The output of the op amp will last for few milliseconds so I'm gonna connect the to latch circuit (8-bit shift register because i want 3 output in order) and the output is connected to decoder to turn 3 inputs to 8 outputs which is connected to diode rom that's connected to 7-segment display That going to display the first letter of the color we are going to detect.

I have to test all sorts of strange things at work. They all require some sort of oddball connection. Every time I need to make something odd connect this is where I start looking.

So my dad who passed back in 09 was, back in his day, big into older electronics, he had this stash of unused tubes back when they adopted me in 83. They're dirty, but all unused. I don't even know where to start with getting rid of them.