HC-SR04 ultrasonic distance sensor is very popular in robotics. Basically, any object avoiding robot uses this sensor. And it is great of course, easy to use cheap and accurate but once you start building more complex robots you can start to see a problem and this problem is time. It takes a lot of time to measure distance with this sensor, there are some alternatives like sharp sensors that can detect objects super fast but output of them is binary so you can detect if there is an object within specified range but you don't know how far. For some robots those sensors are perfect but there is another problem - price. They are almost 10 times more expensive than HC-SR04. So here I started thinking about combining those two together. And I come up with an idea for a module that you can plug to the HC-SR04 and delegate the task of reading the distance to the Attiny microcontroller, output can be binary and your main microprocessor is relieved! Simple but beautiful solution and cheap at the same time :)

I want to use it in one of my next robotic projects, it will simplify programming and make my robot more accurate.

This is PCB only so you need rest of the components to build it, here is the BOM list:

• HC-SR04
• Attiny45/85
• Potentiometer
• Breakaway headers Female and Male
• 1206 SMD resistor 100ohm (better to buy in a kit)
• 1206 LED