@chrissbarr chrissbarr released this Jul 15, 2018 · 3 commits to master since this release

Assets 2

V1.3 was never released, only used for internal prototypes - so this changelog includes the V1.3 and V1.4 changes, so that they may be referred to in one place.

  • Board shrunk from 140mm width to 135mm (restored to original RUMBA dimensions)
    • Maintains previous mounting layout (same as original RUMBA)
  • Power Connector Overhaul
    • Swap to higher-quality screw terminals with better ratings
      • 15A -> 20A Max. Current
      • 12-20AWG -> 10-20AWG
  • USB Overhaul
    • miniUSB replaced with microUSB
      • Attaches more securely to board, harder to damage
      • Latching connector harder to accidentally knock out
      • More common cables
    • ESD protection IC added to USB input
      • Replaces discrete TVS diodes
      • Offers better protection of D+ and D- lines from ESD damage
      • Also offers protection to power/ground rail, which TVS diodes did not
    • Shield added to USB pin header, allows for direct connection of 5-pin USB panel-mount sockets
  • 5V selection jumper replaced with automatic OR-ing diodes
    • No longer any need for user to specify USB or DCDC as 5V source via jumper
    • Board will work from either source
    • Defaults to DCDC when both are present
  • Replace large crystal oscillators with more compact SMD package
    • Takes up less board space + improves board routing
  • Overhauled 12V regulator
    • Newer, more efficient regulator (AOZ1284 replaces LM2596)
      • Regulator current-rating improved from 3A -> 4A
      • Switching frequency increased from 150kHz to 500kHz (allows smaller inductor / higher inductor current-rating)
    • New diode + inductor selected for higher current capability (testing confirms maximum continuous current draw of 2.5A, limited by inductor temperature)
    • Now capable of running up to 12V 30W heater, or 12V fans, etc
    • More compact layout
  • Easier troubleshooting
    • Indicator LEDs added to USB, 5V_DCDC, 5V, 12V
  • Improve board routing
    • Routing of high-current traces and pours near power input and heated bed section have been improved
    • Microcontroller oscillator circuits re-routed and tidied
    • Microcontroller reset circuits re-routed and tidied
    • Routing of all stepper-related signals tidied

@chrissbarr chrissbarr released this Mar 29, 2018 · 20 commits to master since this release

Assets 2

Improvements:

  • Improve 5V Regulator
    • Change inductor L3 to smaller part with higher current rating
    • Change diode D5 to smaller part with higher current rating + simpler footprint
    • Improve routing + polygon pours around 5V regulator to improve thermal conductivity to ground plane
  • Improve 12V Regulator
    • Change inductor L4 to smaller part with higher current rating
    • Change diode D8 to smaller part with higher current rating

@chrissbarr chrissbarr released this Mar 29, 2018 · 25 commits to master since this release

Assets 2

Improvements:

  • Change 5V regulator from LT1933 to AOZ1282.
    • Higher peak efficiency (95% vs 87%)
    • Higher maximum output current (1.2A vs 0.6A)
  • Thicken traces / pours relating to heated bed output
  • Increase spacing around ISP2 and EXP3 headers for easier access
  • Change stepper motor wire labels to match more common cable colours
  • Change stepper driver micro-stepping DIP-switch orientations to be more intuitive

Fixes:

  • Correct DTR pin for USB comms on ATmega16U2
  • Update all screw holes to be uniform, previously were slightly differing sizes
  • Correct D8 footprint to correct footprint for MURS320 as per BOM

@chrissbarr chrissbarr released this Jul 18, 2018 · 36 commits to master since this release

Assets 2

Changes from original RUMBA design:

  • Replace PTC fuses with replaceable automotive mini blade fuses
    • Quicker response in event of short / reverse-voltage
    • Allows > 16V on bed circuit, unlike old design (now full 24V compatibility)
  • Change MOSFETs from PSMN7R0-60YS to PSMN1R8-40YLC
    • PSMN7R0-60YS is not logic-level compatible, RDSon at 4.5V is not defined
    • PSMN1R8-40YLC has much lower RDSon and is logic-level compatible
  • Add flyback diodes to each MOSFET-driven output
  • Correct LCD connector labelling
  • Add 4 x I2C headers for expansion
  • Redo placement and routing of decoupling capacitors
  • Increase board size to 140x75mm