Adafruit High Voltage UPDI Programmer

The Adafruit High Voltage UPDI Programmer is a compact and versatile tool designed to simplify programming and debugging modern ATtiny microcontrollers using the Unified Program and Debug Interface (UPDI). Supporting both 3V and 5V logic, it provides a reliable and user-friendly solution for developers working with ATtiny series chips such as the ATtiny816, ATtiny817, and ATtiny1616.



What sets this programmer apart is its built-in high-voltage (HV) functionality, capable of generating a controlled 12V pulse on the UPDI line. This allows recovery of chips configured to use the UPDI pin as reset or GPIO, effectively “unbricking” devices and restoring them for low-voltage programming. Combined with onboard status LEDs, USB-C connectivity, and a CH340E USB-to-serial interface, it delivers a streamlined and efficient development experience.

What Is UPDI?

UPDI stands for Unified Program and Debug Interface. It is a Microchip proprietary interface and is a successor to the PDI interface, which has 2 data wires. UPDI provides a bidirectional half-duplex asynchronous communication with a microcontroller for programming or debugging.

Quick Spec

• Interface: Unified Program and Debug Interface (UPDI)
• Logic voltage: selectable 3V or 5V
• High-voltage programming: 12V pulse generation (for reset/unbrick support)
• USB interface: USB Type-C (data + power)
• USB-to-serial chip: CH340E
• Loopback resistor: 1K (RX–TX) onboard
• Power capability: up to 500mA via 3V regulator
• Indicators: green power LED, red serial activity LED
• Includes JST-SH 3-pin cable for breadboard use
• Breadboard-compatible 2.54mm breakout pins
• Dimensions: 29 × 17.7 × 4.9 mm

Resources

• Product Page
• Product Wiki
• Window and Mac driver download
• CH340E Datasheet
• UPDI Interface Docs

Shipping List

• 1 x Adafruit High Voltage UPDI Programmer
• 1 x JST-SH 1mm 3 Pin to Du Pont Male