Name: Adafruit Trinket - Mini Microcontroller - 3.3V Logic
Brand: Adafruit
SKU: 1500

Logical pinout · physical placement not verified

BAT+
Battery or external positive input. Adafruit states BAT+ is the Battery + Input pin for a battery, power adapter, solar panel, or other source, reverse-polarity protected.
Type · PowerVoltage · Up to 16V DC; for 3V Trinket use at least 3.5V input, for 5V Trinket 5.5V or higher suggested.
USB+
USB 5V output, present only when Trinket is plugged into the Mini-B USB connector; can be used for USB power sensing or higher-current USB-powered loads.
Type · PowerVoltage · 5V from USB, Adafruit notes 500mA+ available from USB ports.
GND
Common ground for logic and power, connected to USB ground and the regulator.
Type · GroundVoltage · 0V
GPIO #0PB0
Digital input/output; PWM output; I2C data; SPI data input.
Type · GPIOVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #1PB1
Digital input/output; PWM output; SPI data output; connected to the onboard LED.
Type · GPIOVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #2PB2A1
Digital input/output; analogue input A1; I2C clock; SPI clock.
Type · GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #3PB3A3
Digital input/output with caution; USB programming pin; analogue input A3; has a 1.5K pullup to 3.3V for USB communications.
Type · GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #4PB4A2
Digital input/output with caution; USB programming pin; PWM output; analogue input A2.
Type · GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
RST
Reset pin connected directly to the ATtiny85 reset pin and reset button; used to enter bootloader or reset the board, not a GPIO.
Type · Control
3V
3.3V regulator output from onboard regulator. Adafruit says the regulator output pin is about 3.3V on a 3V Trinket and 5V on a 5V Trinket, up to 150mA.
Type · PowerVoltage · 3.3V, up to 150mA

Pin	Type	Function	Voltage
BAT+	Power	Battery or external positive input. Adafruit states BAT+ is the Battery + Input pin for a battery, power adapter, solar panel, or other source, reverse-polarity protected.	Up to 16V DC; for 3V Trinket use at least 3.5V input, for 5V Trinket 5.5V or higher suggested.
USB+	Power	USB 5V output, present only when Trinket is plugged into the Mini-B USB connector; can be used for USB power sensing or higher-current USB-powered loads.	5V from USB, Adafruit notes 500mA+ available from USB ports.
GND	Ground	Common ground for logic and power, connected to USB ground and the regulator.	0V
GPIO #0PB0	GPIO	Digital input/output; PWM output; I2C data; SPI data input.	3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #1PB1	GPIO	Digital input/output; PWM output; SPI data output; connected to the onboard LED.	3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #2PB2A1	GPIO, Analog	Digital input/output; analogue input A1; I2C clock; SPI clock.	3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #3PB3A3	GPIO, Analog	Digital input/output with caution; USB programming pin; analogue input A3; has a 1.5K pullup to 3.3V for USB communications.	3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #4PB4A2	GPIO, Analog	Digital input/output with caution; USB programming pin; PWM output; analogue input A2.	3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
RST	Control	Reset pin connected directly to the ATtiny85 reset pin and reset button; used to enter bootloader or reset the board, not a GPIO.
3V	Power	3.3V regulator output from onboard regulator. Adafruit says the regulator output pin is about 3.3V on a 3V Trinket and 5V on a 5V Trinket, up to 150mA.	3.3V, up to 150mA

Logical pinout · physical placement not verified

Pin details

10 connections

BAT+
Battery or external positive input. Adafruit states BAT+ is the Battery + Input pin for a battery, power adapter, solar panel, or other source, reverse-polarity protected.
PowerVoltage · Up to 16V DC; for 3V Trinket use at least 3.5V input, for 5V Trinket 5.5V or higher suggested.
USB+
USB 5V output, present only when Trinket is plugged into the Mini-B USB connector; can be used for USB power sensing or higher-current USB-powered loads.
PowerVoltage · 5V from USB, Adafruit notes 500mA+ available from USB ports.
GND
Common ground for logic and power, connected to USB ground and the regulator.
GroundVoltage · 0V
GPIO #0PB0
Digital input/output; PWM output; I2C data; SPI data input.
GPIOVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #1PB1
Digital input/output; PWM output; SPI data output; connected to the onboard LED.
GPIOVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #2PB2A1
Digital input/output; analogue input A1; I2C clock; SPI clock.
GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #3PB3A3
Digital input/output with caution; USB programming pin; analogue input A3; has a 1.5K pullup to 3.3V for USB communications.
GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
GPIO #4PB4A2
Digital input/output with caution; USB programming pin; PWM output; analogue input A2.
GPIO, AnalogVoltage · 3.3V GPIO output level; Adafruit warns not to use with 5V inputs.
RST
Reset pin connected directly to the ATtiny85 reset pin and reset button; used to enter bootloader or reset the board, not a GPIO.
Control
3V
3.3V regulator output from onboard regulator. Adafruit says the regulator output pin is about 3.3V on a 3V Trinket and 5V on a 5V Trinket, up to 150mA.
PowerVoltage · 3.3V, up to 150mA

Start wiring

USB · 3.3 V

Confirm the data interface matches your host board.

Module pins: BAT+, USB+, 3V, GND, GPIO #0 / PB0, GPIO #1 / PB1, GPIO #2 / PB2 / A1, GPIO #3 / PB3 / A3. Schematik maps them to your board in the app.

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