Printrboard: 3D-Printer Controller

The Printrboard is a AT90USB1286-based, 4-axis CNC controller with high-current outputs and temp sensors suitable for 3D-printers

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The Printrboard electronic set was designed by Laine Walker-Avina, of the Printrbot team, in order to eliminate the production and functionality shortcomings of older RepRap electronics sets. Printrboard improves upon the previous production-grade electronics set (Gen6) by adding heatbed and SD card support, reverting to 1/16 microstepping Allegro stepper drivers, and improving connectivity reliability and reducing cost by elimination of the FTDI UART chip. Printrboard also has expansion headers supporting I2C, SPI, UART, and ADC pins. All extra I/O ports of the AT90USB have been broken out to headers for prototyping and expansion.
Printrboard is a derivative of Teensylu, an AT90USB1286 development board originally based on Sanguinololu. The Atmel AT90USB1286 MCU has on-chip USB, removing the need for the FTDI UART (USB-to-serial) IC. On-chip USB means dramatically faster firmware upload times and communication. Currently shipping in tens of thousands of printers sold by Printrbot.


  • Atmel AT90USB1286 Microcontroller (or AT90USB1287 drop-in compatible for 20mhz support)
  • Native USB interface. No FTDI serial-to-USB chip!-- 128kb Flash
  • Four integrated Allegro A4982 Stepper Drivers (no Pololus needed)
  • On-board 4-channel DAC to control stepper set current (Rev F)
  • Thermistor Connectivity: 2
  • 2 N-MOSFETs for Extruder and Heatbed control
  • 1 N-MOSFET for low power Fan or motor
  • Onboard SD card slot
  • Four Endstop connectors supplied @ 5V. Includes X, Y, Z, and fourth endstop called E-Stop to be used as an emergency stop, or extruder stop (to be added in firmware).
  • Supports multiple power configurations (Carried from Sanguinololu)
  • Logic & Motors supplied by ATX or laptop power supply (12-20V 120W minimum)-- Logic supplied by USB bus (if enabled by solder jumper)-- Logic supplied by on-board voltage regulator-- on-board USB connectivity
  • Edge connectors enabling right-angle connections
  • Dedicated I2C connector (Rev F)
  • FET-based buffer for Z-endstop to support 12V inductive bed sensors (Rev F4)
  • 14 Extra pins available for expansion and development, with the following capabilities
  • UART1 (RX and TX)-- SPI (MOSI, MISO, SCK)-- PWM pin (1)-- Analog I/O (6)-- JTAG (uses some of the ADC pins)
  • Additional 14 pin header with remaining I/O for prototyping
  • SMT Components sized at 0805, and no QFNs for easier soldering.
  • 4-Layer PCB with proper ground plane and power distribution networks
  • Small design - board is 100mm x 60mm (4" x 2.4")

  • 1 × AT90USB1286 Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers
  • 4 × Allegro A4982 Stepper Motor Controller
  • 1 × TI LM2841 Switching Buck-Converter
  • 1 × TI TXB0104 Bi-directional Level Translator
  • 1 × Microchip MCP4728 I2C DAC

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Frank wrote 05/22/2020 at 15:38 point

I got Same Board Rev B on a Printrbot orginal. and like Upgrade have only the 1.0 Firmware on it

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seasaltchap wrote 10/09/2014 at 23:54 point
For the z-axis pair of motors I am looking for instructions to wire a " Hand wheel Pulse Encoder 100PPR CNC Mill Router Manual Control For CNC System" [example, item:-171327933584] from EXP2.
And maybe the driver code too.

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