Finally completed a thing on my bucket list for a long time, my own ESP32 Prototype Development Kit.

ESP32 is a powerful embedded development board. But the ESP32 DevKit design is not much breadboard friendly and has a weird pinout design. That is why I designed this development kit, to make my experiments easier with the help of built-in electronic components and breadboard.

I decided to share it open-source under Creative Commons Attribution-ShareAlike 4.0 International License.


  • Expanded GPIO pins with 3.3v and GND
  • A tiny breadboard
  • Li-ion battery
  • USB charging controller
  • Adjustable voltage booster (set to 5v)
  • SSD1306 LCD module
  • 3V3-5V logic level shifter (4 channels)
  • 4 x LEDs (Red, Green, Blue, Yellow)
  • 2 x DIP switches
  • 2 x Pushbuttons
  • 1 x Trimpot (10 kOhm)
  • 1 x Active buzzer

And I decide to make this open-source, so you can find the schematics and Gerber files from GitHub

5DOF Robot Arm

මේ තියෙන්නේ මම ලගදි හදපු Robot Arm එකක්. තාම හදලා නම් ඉවර කරලා නෑ. Design එකට මූලික අදහස ගත්තේ Dorna කියන robot arm එකෙන්. Stepper motors වලින් තමයි වැඩ කරන්නේ. (Nema17 මෝටර් 3 යි, 28BYJ-48 මෝටර් 2 යි) Firmware එක විදිහට grbl-5x සහ Development board එක විදිහට Arduino Mega 2560 + Ramps 1.4 පාවිච්චි කරලා තියෙනවා.

ගොඩක් කොටස් හදලා තියෙන්නේ 3mm Cladding Boards වලින්. හැම කොටසක්ම ව⁣ගේ කැපුවේ මගේ CNC Machine එකෙන්.

DIY Robot Aarm

Another 'Holiday Engineering' project on its final stage.

Now my newly made 3 DOF Robot Arm can solves 'Tower of Hanoi' problem

The design was based on the 'uARM metal' project and I did some updates with available materials. Firmware is GRBL 1.1, which is used to control CNC machines.

Need some position calibration mechanism and coordinate mapping function from Cartesian to Cylindrical for stepper motors driven by CoreXY arrangement.

For your Interest:

SAP I computer from basic Logic ICs

Does anyone have an idea about early computers? The age before Micro controllers/ Microprocessors? I have just now completed a project that takes me into that time.

This is an 8-bit Minimum Computer (Computation Machine) [1] that made from simple logic ICs, flip-flops and a few memory modules. It has a memory of 16 bytes and its maximum clock speed is not more than 5 Hz.

The whole design is based on SAP-I Architecture and design was obtained from Ben Eater’s Youtube Channel [2]. Currently, it has 9 instructions (based on Intel 8080 instructions) and can be programmed it using machine language (That means programming from 1s and 0s)

The project was started as a project for CO221: Digital Design Course, Department of Computer Engineering, University of Peradeniya.

All the Printed Circuit boards were designed from the basics by us using Fritzing, fabricated by using the CNC, Builder_V3 and soldered and assembled by us. It took 2 months to complete the fabrications and another month for build motherboard (30x40cm) and debugging.

After the evolution of the project, we hope to make it free and open source under Apache License 2.0

Special thanks to

  • Dr. Kamalanath Samarakoon for giving the idea & source materials about SAP-I
  • Dr. S.D. Dewasurendra
  • Miss. Narmada Balasooriya, Miss. Thilini Dahanayaka and all the instructors on the Department of Computer Engineering
  • My team members; Suneth Samarasinghe, Pubudu Premathilake, Dilshani Karunarathne, Wishma Herath, Pasan Thennakoon & Irfan Mohommad