Tag Archives: breadboard

Versatile And Open Source LiPo bBattery Breadboard Power Supply

Orlando Hoilett from Calvary Engineering LLC designed a  versatile Li-Po battery breadboard power supply and wrote an Instructables on it. This power supply outputs 3.3V to the breadboard and takes input from a single-cell LiPo battery. The breadboard power supply also has the ability to charge the battery without needing to separate it from the circuit board. More importantly, this project is licensed under Open Source Hardware which means anyone can modify, distribute, make, and sell this design.

LiPo bread board power supply
LiPo breadboard power supply

Key Components

The complete BOM is available at the GitHub repository.

  • JST connector
    This connector connects directly to the LiPo battery.
  • 3.3V regulator, AP2210K
    3.3V logic is getting increasingly popular among electronics hobbyists and engineers. Also, boosting 3.7V of a LiPo battery to 5V can induce quite a bit of switching noise on the power supply. Linearly converting 3.7V to 3.3V is the best way to avoid this problem.
  • Battery Charger, MCP73831T
    This power supply has a charger built into the board so you can charge the battery without removing it from the power supply.
  • Voltage Selection Jumper
    The voltage selection headers are 3 pin male headers and they are labeled as 3.3V (or VReg) and VRAW (or LiPo). Connect the center pin to 3.3V to get power from the regulator. Connect the center pin to VRAW to get power directly from the LiPo battery.
  • DPDT Switch
    This switch lets you power down the board without removing the battery.
  • LED indicators
    LEDs are used to indicate the current status of the board.


This board breaks out the LiPo battery to the breadboard power rails on both sides. It has a DPDT switch to power down the board. The AP2210K IC has an ENABLE pin which is pulled down to the ground using the DPDT switch in order to enter the low power mode. In low power mode, the regulator and all the LEDs get disabled and draws almost no current from the LiPo. More about the AP2210K regulator IC is on this datasheet.

LiPo breadboard power supply schematic
LiPo breadboard power supply schematic

Another great feature of this breadboard power supply as mentioned earlier is, it incorporates an MCP73831T LiPo battery charger IC. It is a widely used PMIC (power management integrated circuit) for charging LiPo batteries. The LiPo battery should be connected to pin 3 (VBAT) and 5V should be applied to pin 4 (VDD).

The chip starts charging as soon as it detects 5V input and stops charging when the battery is full. Charging current is limited to USB standard i.e. 100mA by connecting a 10.2K resistor between pin 5 (PROG) and ground. So, it’s completely safe to charge the battery from your laptops USB port. Other host microcontrollers can check the battery status using pin 1 (status pin) of MCP73831T.

Breadboard Friendly ATTiny85

Chris @ chris3d.com build his own Attiny85 board:

 The modularity of Arduinos is great, but after playing with them for a year or so, I wanted to start building things that needed a little more integration. I also wanted to design the components and programming around the actual controller I’d be using. So, I decided to start by building a small breadboard friendly ATTiny85.

Breadboard Friendly ATTiny85  – [Link]

STEMTera, Arduino Compatible Built-In Breadboard

Sydney backyard inventor, JP Liew, who invented MicroView that had successfully raised USD 573,000 in 30 days on Kickstarter two years ago has just launched STEMTera Breadboard on Kickstarter, an open source invention that solves many electronic prototyping problems and aids in teaching STEM (Science, Technology, Engineering and Maths). The initial funding goal of USD 35,000 was reached in less than 64 hours!

STEMTera is the first breadboard with an Arduino compatible built-in that works with thousands of shields. With ATmega16U2/32U2 exposed, and native USB projects can be easily developed using the LUFA framework. It is specifically designed to solve common issues using Arduino with a breadboard especially in the lab or classroom. It came to reduce the headache of managing students’ messy wires flying around microcontroller board and breadboard during class, to enhance the current design (Arduino UNO) for native USB development without changing or adding extra components, and to Improve adaptability, mountability and protection, enabling more projects to be built in the lab or classroom. STEMTera is 111.8 x 79.8 x 16.1 mm sized and weighs 132 grams.

Thanks to exposing ATmega16U2/32U2, users can now develop native USB projects with an extra 21 IO pins. These extra IO pins can work directly with the LUFA framework without having a middleman to translate messages like the original Arduino UNO.

“STEMTera Breadboard was designed to help Australian schools teach STEM education and help students make and invent things. My demonstration video showed how easy students can build Hydroponics Systems, game controllers and musical instruments using the STEMTera Breadboard.” – JP Liew, founder of STEMTera.

STEMTera Features

  • Dual Microcontroller – ATmega328P & ATmega16U2: With a total of 41 IO pins of which 9 provide PWM. Pin-to-pin compatible with Arduino UNO R3 shield .
  • LEGO® Compatible Bottom Cover
  • USB Native Development – thanks to the exposed ATmega32U2
  • 4 LEDs (Power, TX, RX and L)
  • Strong ABS Enclosure
  • IDE Support
    • Atmel® Studio
    • Arduino IDE
    • AVR-GCC
    • AVR-GCC with LUFA
    • Scratch

Check this review by Sparkfun:

The STEMTera is available for pre-order and it will be shipped soon. You can pre-order it now for $45 on Sparkfun, on of the project’s distributors, and choose the color you prefer out of white, black or pink! More colors will be produced later.

More details about STEMTera can be found on the official website and the campaign page. Also check out JP Liew homepage to know more about his previous projects.

How to build an Arduino Uno on a BreadBoard


“webgeeks” show us how to setup an Arduino UNO on a breadboard – aka bare minimum arduino:

If you are like and me and enjoy building electronic projects then you might have worked with the Arduino Uno. The Arduino uno is the most popular micro controller of the series and has a large collection of libraries which make working with it very easy. So there would be times where you may need more than one Uno for the project, I like to make my own micro controller rather than buying a new one, as this saves me some money which may be helpful for other such projects.

How to build an Arduino Uno on a BreadBoard – [Link]

ESP8266 Breadboard Adapter


Markus has designed a single-sided ESP-12/ ESP-07 breadboard adapter that uses easy to find SMD parts and has on-board voltage regulator.


* Fits ESP-12 and ESP-07 module
* Single-sided self-etchable design
* Few, cheap parts in SMD
* Breadboard-style – one row on each side accessible
* Vin >4.5V (max. 7V) input possible with 3V3 onboard voltage regulator (with two capacitors 10µF)
* Power-indicator LED
* (Schottky-) Diode as reverse polarity input protection possible (solder 0 Ohm resistor or just connect the two pads for no protection)
* RST, CH_PD, GPIO0 with 4k7 pull-up resistors on board (resistors can be omitted if remote access of those GPIOs is needed)
* GPIO15 with 4k7 pull-down (see above)
* Tactile switch connected to GPIO0 to get into flash mode
* Single post for 3.3V output near voltage regulator

ESP8266 Breadboard Adapter – [Link]

Homemade breadboard


by robertgawron.blogspot.com:

A breadboard can be also made at home, from one side, it will be more expensive than those on the markets, but for another side, it’s possible to add commonly used elements, like LEDs, switches, or other things, for example I added a precision IC socket that makes putting in and out of ICs much easier. Choosing what to put there is a bit like a making homemade pizza, one can put anything he likes (and what he has currently in the fridge).

Homemade breadboard – [Link]