Pololu USB AVR Programmer v2.1

Overview

The Pololu USB AVR Programmer v2.1 is a compact, low-cost in-system programmer (ISP) for AVR microcontrollers from Atmel (now a part of Microchip). The programmer provides an interface for transferring a compiled AVR program from your computer to the target AVR’s non-volatile memory, allowing it to run the program. It is a good solution for programming AVR-based controllers like our A-Star 328PB Micro and Orangutan robot controllers. It can also be used to update, replace, or remove the bootloader on some Arduino boards including the Uno, Leonardo, and Mega. This programmer is designed to work well with both 3.3 V and 5 V devices, and it can even be configured to provide power to the target device in low-power systems.

The Pololu USB AVR Programmer v2 (bottom) connected to an A-Star 32U4 Prime SV for programming.

Features and specifications

• Connects to a computer through USB via a USB A to Micro-B cable

• Emulates an STK500 programmer through virtual COM port interface

• Works with standard AVR programming software, including Atmel Studio, AVRDUDE, and the Arduino IDE

• Configuration software available for Windows, Mac OS X, and Linux

• Supports both 3.3 V and 5 V devices; can automatically switch operating voltage based on detected target VCC

• Can optionally power the target at 3.3 V or 5 V in low-power systems

• USB-to-TTL serial adapter functionality for general-purpose serial communication

• Provides a 100 kHz clock output, which can be useful for reviving misconfigured AVRs

• All I/O pins are protected with 470 Ω resistors

Bonus feature: TTL-level serial port

This programmer doubles as a USB-to-serial adapter. The programmer installs as two virtual COM ports: one for communicating with programming software and one for general-purpose serial communications. This means that you can seamlessly switch between programming an AVR and debugging it through the TTL serial port without having to open and close your terminal program. In addition to the serial transmit (TX) and receive (RX) lines, the programmer lets you use A and B as serial handshaking lines that can be configured using our software.

The six pins on the serial header (GND, A, VCC, TX, RX, and B) are arranged to be similar to the pinout of commonly-available FTDI USB-to-serial cables and breakout boards. In the default configuration, pin B is used as the DTR output (and pin A is an unused input), which allows you to plug the programmer directly into a variety of Arduino-compatible boards (including our A-Star 328PB Micro) and use it to upload programs to the board via a serial bootloader.

The Pololu USB AVR Programmer v2 (top) connected to an Adafruit Pro Trinket for programming.