MINITRONICS v. DATASHEET Author Bart Meijer Date 2th of April 23 Document version. ReprapWorld.com
PRODUCT OVERVIEW Minitronics is the latest development of ReprapWorld.com. It's designed to be an easy to use, compact and smart solution to fit 9% of the 3D-printers. Unlike the Megatronics, which targets at the advanced ranged of usages, the Minitronics is plug and plug, which will fit the needs of the average user better. Megatronics has a powerful Atmega28 processor with 28 KB memory, running at 6Mhz. The board can be connected to a PC using a normal USB cable. It will register as FTDI FT232R device. The board is compatible with Arduino and will therefor be easily programmed from the Arduino IDE. 2
TECHNICAL SPECIFICATION Microcontroller Atmega28-6MU Operating Voltage Electronics 5V Operating Voltage High 2-24V DC Current per I/O Pin 4mA Clock Speed 6Mhz MAJOR FEATURES Atmega28 Powerful Atmega28 processor with 28 KB memory, running at 6Mhz Four MOSFETs The board has 3 regular MOSFETs and one MOSFET for the heated bed (A) to support many needs. 3
Up to 5 stepper drivers /32 step The Minitronics has four on board stepper drivers. A fifth can be connected externally, using our External stepper driver board. Small dimensions Only 93.9 x 56.8mm x 8mm, comparable with Sanguinololu Detailed feature list Microcontroller Atmega28-6MU Powerful Atmega28 processor with 28 KB memory, running at 6Mhz Nr. of extruders 2 (using external stepper motor) Nr. of end stops 3 Nr. of thermistors 2 Input voltage Max 2V when SRC2v is jumpered, else 2-24V Nr. of stepper drivers 5 (4 on board with /32 step, externally) 4
OTHER FEATURES Auto reset can be disabled by removing a jumper The 5V logic circuit can be powered from 2V (2V MAX!), by setting a jumper 2V has a diode to protect against reverse polarization The 5V line is protected by a 5mA resettable fuse Four layer high quality PCB board 5
CONNECTORS Name Description USB jumper When jumpered powers the board from USB (5V) RSTEN jumper When jumpered enables reset (DTR). Without it the board cannot be programmed using the IDE. It's recommended to remove the jumper for production machines. ICSP 2x3 header to program the Atmega chip directly AUX 2x4 header for peripherals (I2C). SCL 2. D25 3. SDA 4. D26 5. D9 6. D3 7. GND 8. 5V X X End stop Y Y End Stop 6
Z Z End Stop T Thermistor T2 Thermistor 2 FAN Output for a fan (same voltage as pwrin) * OUT5V 2x header for 5V output OUT2V 2x3 header for 2V output (same voltage as pwrin) * 2V +2V line input (A Max) when SRC2v is NOT jumpered up to 24V is accepted. * 2V2 +2V2 line input for heated BED (A Max) can handle up to 24V. * XMOT,YMOT,ZMO Connectors for bipolar stepper drivers (ZMOT and ZMOT are T,ZMOT,EMOT the same stepper driver) JP-4 Stepper mode selector for stepper drivers, left-to-right or bottom-to-top: Jumper Jumper 2 Jumper 3 Resolution Full step Half step ¼ step /8 step /6 step /32 step /32 step /32 step SRC2v jumper Power the board from 2V. WARNING: MAX 2V is accepted * EXTSTEP Breakout to hook up an external stepper driver. Enable 2. Step 3. Dir 4. GND PWRIN 2V power input * * When powering from 24V make sure your heaters and other peripherals can handle 24V as well. 7
PIN DEFINITION This is the digital I/O assignment for Minitronics. You can use it to adjust your firmware to match Minitronics. I/O D D D2 D3 D4 D5 D6 D7 D8 D9 D D D2 D3 D4 D5 D6 D7 D8 D9 D2 D2 D22 D23 D24 D25 Function RxD TxD Y endstop Heated Bed X Endstop Z Endstop Mosfet 3 Mosfet 2 Mosfet ICSP (SCK) (MOSI) (MISO) (SS) SCL SDA AUX (D9) AUX (D25) I/O D27 D28 D29 D3 D3 D32 D33 D34 D35 D36 D37 D38 D39 D4 D4 D42 D43 D44 D45 D46/A D47/A D48/A2 D49/A3 D5/A4 D5/A5 D52/A6 Function Stepper E Enable AUX (D3) External Stepper pin 3 (Dir) External Stepper pin 2 (Step) External Stepper pin (Enable) Stepper Y Enable Stepper Y Step Stepper Y Dir Stepper Z Enable Stepper Z Step Stepper Z Dir Stepper E Dir Stepper E Step Debug LED Stepper X Dir Stepper X Step Stepper X Enable Thermistor T2 8
BOARD DIMENSIONS Board dimensions: 93.9 x 56.8mm x 8mm List of M3 holes (measured from the bottom left): 2.3, 2.3 2.6, 54.65 9.9, 2.25 9.9, 54.6 9