Dec 16, 2013

SAV MkI 3d printer electronics board

SAV MkI open source control electronics board made by RepRap CloneWars community is on Indigogo now.



From RepRap wiki SAV MkI page:

This 3D printer board electronics has been designed and developed using all the great contributions and feedback from the RepRap CloneWars group in Spain. All shortcomings from other similar boards have been addressed providing an affordable yet feature rich 3D printer electronics. The SAV MkI, improves upon the previous production-grade electronics set (Gen6, sanguinololu) by adding well dimensioned power MOSFETS, SD card support, on-board regulated 3.3V to connect to 3.3V level peripherals such us Bluetooth, as well as improving on USB link's reliability and reducing cost by eliminating the FTDI UART chip.
The SAV MkI is a derivative of Teensylu and the Printrboard, an AT90USB1286 development board originally based on Sanguinololu. The Atmel AT90USB1286 MCU has an on-chip USB, removing the need for the FTDI UART (USB-to-serial) IC. On-chip USB means that you will get faster firmware upload times, communications, g-code transfer and reduce the time file transfers take from the host to the on-board microSD card. The AT90USB connects at any baud rate regardless of firmware configuration, and operates virtually free of serial communication errors/pauses.

In addition, the SAV MkI has broken out the second UART with its levels adjusted to 3.3V logic. You will be able to connect any HC-05 or HC-06 bluetooth dongle to wirelessly control your printer.
Features
Feature rich yet affordable 3d printer electronics. The SAV MkI has been designed after taking feedback from the Clone Wars RepRapers out there. We have come through with an electronics that we believe will meet your expectations.
  • Hotend and heatbed well dimensioned FETs that can take up to 15A without heat-sinks.
  • High speed native USB interface connectivity going up to 12Mbps so that there is no lag on your prints.
  • As opposed to the 38400-115200 baud via FTDI. The end result is: virtually no serial communication errors (common with Sanguinololu and Generation_6_Electronics).
  • 12V built-in fan controller for your layer fan or hot end cooling.
  • Micro SD reader for autonomous printing.
  • Bluetooth dongle (dongle not provided, tested with HC-05 and HC-06) interface adapted to its logic levels for wireless operation.
  • Expansion bus to connect a keyboard and LCD.
  • Support for 4 standard pololu compatible stepper motor drivers.

RepRap Wiki page with detailed information:

http://www.reprap.org/wiki/SAV_MKI

Indiegogo campaign:

http://www.indiegogo.com/projects/sav-mki-3d-printer-electronics


Technical specifications:

Processor

Atmel AT90USB1286 Microcontroller @16 MHz
Native USB interface
Flash: 128KB
RAM: 16KB
EEPROM: 128KB

Supply: 4.2V to 5.5V
Voltage input: 12V-15V
Internal regulated voltage: 5V and 3.3V

Logic supplied by on-board voltage regulator through Vin Logic can also be supplied through USB (internal source selection).
Connectivity
Edge connectors enabling right-angle connections
2 x 15A switching connectors with high power N-MOSFETs.
1 x switching N-MOSFET for low power fan.
1 x on-board uSD connector
Bluetooth interface output levels adjusted for 3.3V logic (connected to UART1 - Rx and Tx).
4 x Endstop connectors supplied @ 5V. Includes X, Y, Z and E
2 x Thermistors
14 Extra pins available for expansion and development, with the following capabilities
UART1 (RX and TX)
I2C (SDA and SCL)
SPI (MOSI, MISO, SCK)
PWM pin (1)
Analog I/O (6)
JTAG (uses some of the ADC pins)
Dimensions: 100mm x 65mm

SW, Firmware and SDK

All preassembled SAV-MkI come pre-loaded with a bootloader and Marlin firmware. You may also upgrade the firmware, modify calibration data for use with another style of RepRap, or perhaps assemble your own board.
Highlights
Marlin (pre-loaded) - Marlin's main branch already supports the SAV-MkI (MOTHERBOARD==83)
you can also get a pre-configured version of Marlin for the SAV MkI.
Bootloader: LUFA's CDC Bootloader
SDK: Arduino IDE with Teensy add-on.
Windows users only, will need to install USB Serial device (will be downloaded with the Teensy environment).

To use a SAV MkI, you will need to load appropriate USB drivers, you can get them from:
Windows-only: USB Serial Device (PRJC.com)
Compatible Firmware
Marlin Marlin: Official support, use (MOTHERBOARD==83)
Repetier List_of_Firmware#Repetier-Firmware: No support yet.

(Other firmwares are currently untested but any firmware for an arduino mega should work with proper pin setup).