Trinket Microcontroller 3V3

Trinket 3V3 Microcontroller

Note: the Trinket USB bit-bang technique used on this board no longer works as well as it did in 2014, due to incompatibilities with modern computers. Therefore, although the Trinket may be of interest to people who want to maintain some older projects, it is not recommended for projects involving more recent components.

Although small, the size of Trinket must not mislead you. This little micro-controller board was built around the tiny but powerful Atmel ATtiny85 chip.

Both versions of the Trinket, the 3V3 one and the 5V one, work the same, but they present different operating logic voltages.

• La versione 3V3 è ideale per interfacciarsi con dispositivi e sensori che hanno bisogno di una logica 3V3, se decidi quindi di alimentare questa versione con una batteria LiPo, o se desideri collegarla al GPIO del tuo Raspberry Pi direttamente senza convertitori di livello logico. Note that the 3V3 Trinket version should run at 8 MHz only. Its latest version is just 27x15mm and instead of a miniB, it comes with a micro-B USB connector.

As this micro-controller board is small enough, it can fit into any of your projects, and it also is cheap enough to purchase at once. It is perfect if you do not want to abandon your expensive dev-board and you are reluctant to get rid of the project you designed so enthusiastically. It is the cheapest arduino-IDE programmable board.

In the following Pimoroni image, you can see the pin functions of the Trinket 3V

Despite being so small, the ATtiny85 is a fun processor. It has 8K of flash and 5 I/O pins, with either PWM ‘analog’ outputs and analog inputs. A USB boot-loader allows it to be plugged into any computer to reprogram it over a USB port, exactly like an Arduino does. A few simple modifications to the Arduino IDE make it work like a mini-Arduino board. It is not possible to stack a big shield on Trinket, but it may be your ideal platform for many small and simple projects.

Useful specifications:

• ATtiny85 on-board, 512 bytes of EEPROM, 512 byte of SRAM, 8K of flash.
• This USB boot-loader with a lovely LED indicator looks exactly like a USBtinyISP. This means you may program it with AVRdude (after a simple config modification) and/or the Arduino IDE (after a few simple config modifications).
• Micro-USB jack either for power and/or for USB uploading. You may put this product in a box or also tape it up. When you want to reprogram, use any USB cable.
• The boot-loader process is absolutely rugged and foolproof, you will not experience any failure halfway through a project.
• ~5.25K bytes available for use (for the boot-loader, 2.75K are taken)
• 3.3V power regulator on-board, with an output capability of 150mA and ultra-low dropout. Up to 16V input, thermal and current-limit protection, reverse-polarity protection.
• Powered either with USB or with external output (as for example a battery). It will switch over automatically.
• On board red pin #1 LED and green power LED.
• Reset Button: to enter the boot-loader or restart the program, use this reset button. It is not necessary to unplug/replug the board whenever you want to reset or update.
• 5 GPIO, 2 are shared with the USB interface. On the other 3 independent IO pins you find 1 analog input besides 2 PWM output. On the 2 shared IO pins you find 2 more analog inputs and 1 further PWM output.
• Hardware I2C / SPI capability for breakout & sensor interfacing.
• Works with a lot of basic Arduino libraries and Adafruit Neopixel, too.
• Mounting holes as well.
• It is extremely small.

Consult the introducing Trinket tutorial by Limor. It is fantastic as it includes a lot of details, pin outs, examples, and more.

Adafruit name: Trinket – Mini Microcontroller – 3.3V Logic – MicroUSB [ADA1500]