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
v1.4
5 years ago
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
V1.2
6 years ago
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
V1.1
6 years ago
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