The Toadstool: Faster Microcontroller Prototyping

Toadstool Logo

Toadstool Mega328
Toadstool: A modular platform that lets you quickly and easily build microcontroller projects. Ideal for makers wanting to move beyond the Arduino ecosystem, or for experienced enthusiasts and professionals wanting to speed up prototyping.

Now Live! The prototyping process is over – the Toadstool is alive!

Faster Prototyping

Toadstool Meg328

Speed up your prototyping with a self-contained module that connects directly to your breadboard. The Toadstool houses the microcontroller and supporting components, along with a power-supply and programming/debugging header. All I/O pins are broken out and labelled to get you up and running faster.

List of features >

Flexible Prototyping

Toadstool with Cap

Bring flexibility to your projects that other prototyping platforms don’t offer. The Toadstool range of boards supports microcontrollers from a number manufacturers, including Atmel and Texas Instruments. Features include a voltage selection jumper, and flexibility to choose the crystal that suits your application.

List of features >

Modular Prototyping

Modular Prototyping

Use a range of caps to further simplify your prototype. Popular breakout boards, known as caps, connect to all Toadstool prototyping boards using a standard connector. The connector carries SPI, I2C, and UART signals to allow the connection of a range of small modules without reducing teh size of your main prototyping area. Your prototypes will be faster to put together, and have less wires getting in your way.

List of features >

Features and Benefits

The Toadstool was designed to be feature-rich, flexible and easy to use. We thought that it was worth sacrificing the “fits on the tip of your finger” sexiness for a cool design and loads of features!

  • Plugs directly into your breadboard: no jumper wires running from dev board to breadboard
  • Self Powered: Great for standalone prototypes, with an on-board voltage regulator
  • Voltage Selector: Choose which voltage to operate at using the voltage jumper
  • Choose your Crystal: Connect the crystal that suits your application best
  • Program & Debug: The on-board header allows quick, easy programming and debugging
  • Safe Power: The on-board regulator is protected against switched polarity and fused to prevent over-current conditions
  • Caps: Toadstool Caps allow you to connect popular modules supporting SPI/I2C/UART protocols
  • DIP Packages: most Toadstool boards contain DIP packages, so you can easily switch microcontrollers in and out
  • Multi-manufacturer: The common footprint and Caps interface means you can use the best microcontroller for your application, and still use the same Toadstool Caps

Toadstool Boards

Toadstool Mega328
Two Toadstool prototyping boards have already been released:

  • Toadstool Mega328: Atmel ATmega328P
  • Toadstool MSP2553: TI MSP430-G2553

With more in the oven!

Toadstool Caps

Toadstool Cap
We have developed two Toadstool Caps:

  • 24LC EEPROM: 24LC128 EEPROM chip
  • RTC: MCP79400 Real Time Clock

With more on the way!

  • USB-Serial Converter
  • Humidity Sensor
  • Twiddly Buttons and flashing LEDs


Example Code: We’re working on a list of resources to get you up and running even faster. Visit our Github repository for sample projects

FAQ: We’re working on a set of Frequently Asked Questions to help get you started. Pop on over if you need more info on the Toadstool family


oshw logo

Crash-Bang Prototyping are big fans of Open Hardware, and in line with the ethic of sharing the Toadstool is an Open Source Project.

All schematics and layouts (which were made with the awesome Open Source Kicad EDA software) are available on our Github repository. Please download, share, and most importantly feed back!

4 Comments on “The Toadstool: Faster Microcontroller Prototyping

  1. I have really enjoyed the Beyond Arduino series. Everything has worked so far mainly because the examples are well documented and the articles very instructive. I tried doing this with the PIC a few years ago but having some help with the datasheets makes all the difference in the world. I haven’t gotten the temperature logger to work all the way yet but am working on it. It shows the help screen and I set the date but I haven’t seen the temperature logged yet. I like the way you are working through capabilities of the AVR module by module.

    The Toadstool is great also. No more dealing with all the wires. Looking forward to some additional CAPS. It did take me awhile to figure out I needed to change the clock speed before it would work according to the articles.

    Some ideas for future articles would be working with a rotary encoder with LCD Display. I did get a PIC to read a Maxim DS18s20 temperature IC awhile back but would like to work with one wire devices and a display to see multiple temperatures.

    • Hi Ripley – Thanks for the positive feedback, really pleased that the article structures work for you! I haven’t worked with PIC, so can’t compare, but do remember that once I became comfortable with datasheets it completely changed my ability to work with the MCU (and additional modules). If you still aren’t winning with the logger, pop me a mail and maybe I can help?

      I’m very biased, of course, but I also like the Toadstool! It’s the third incarnation of my original prototyping board, and I use it all the time – great that it works for you too. Thanks for flagging the clock speed – I’ll make sure I set that up before shipping in future.

      Finally, thanks for the thoughts on future articles. I’m a little stretched for time right now, so may be a while, but I like the ideas.


  2. I “kept track” of your articles each month, thinking sometime I will dive in. Now is the time (Jan issue). I have spent hours in the datasheets and on Studio 7. i was lost in a rabbit hole and decided it was “time”. Love it!
    Question on the AtmelICE. Did you get it? Was the basic kit enough, or did you move up to the top dog? I am trying to decide on the programmer.

    Thanks for your time and effort. (I am 70, started building microprocessors with Motorola 6800, then went astray.)

    • Hi Greg

      I’m so pleased you’ve taken the plunge! As you say it is a rabbit hole and it is a load of fun. Yes, I did buy the Atmel Ice, and found for my purposes the Basic did the trick both for programming and debugging. Debugging is a little tricky, so when you get to the point where you want to interactively debug your projects make sure you take a look at this post:

      Good luck and please stay in touch!

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