Hello everyone! I’m excited to introduce Luna, a 3D printer controller with a focus on network connectivity that I’ve been developing for the past few months. Here’s a little tour of the hardware:
Runs RepRapFirmware. Feature set is based on Duet 3 Mini 5+, with some changes:
On-board WiFi and Ethernet
One dual-port driver
Five on-board regulators: (1) 5V, 3A + 3.3V, 1A for core components (2) 5V 3A + 3.3V, 1A for expansions such as NeoPixel, EXP1, EXP2, etc. and (3) 12V, 3A for 12V devices
More input/outputs (IO0 - IO6)
Dual processor design: ESP32-S3 + SAM E5 microcontroller. ESP32-S3 is a dual-core, 240 MHZ WiFi + Bluetooth SoC with 8MB flash, 512K SRAM; handles networking, storage (SD card) and interfaces (USB, PanelDue, RepRapDiscount Full Graphic Smart Controller).
SAM E5 is a Cortex-M4F microcontroller running at 120 Mhz, with 512KB flash and 196K SRAM; handles kinematics, stepping, digital/analog IO and other real-time control.
Will have open schematics and PCB design, created with KiCad. Firmware will also be open (goes without saying as it is RepRapFirmware).
There is still some work to be done, but I’m hoping to do a crowdfunding campaign in the future. This thread is open to questions; suggestions are also welcome and may make it to the final hardware as long as it’s not a major change. You may also just express general interest, if you have no questions/suggestions
I like using 24V for heating and steppers, but the options for high-quality 24V fans are so limited. Right now I have my always-on cooling fan running through a buck converter but part cooling I can’t do that. I could just limit the part cooling fan to max 50% duty cycle and use a 12V fan, but running 12V for the fan would be better.
Does that include hosting a web control panel, like Grbl_Esp32 does?
What’s your expectation for how end stops are hooked up? Is it IO0-IO6? If so, are they debounced for mechanical switches? Or would you expect, say, CAN endstops? (I know that TMC2209’s have the option for sensorless homing, which I use for X and Y on one of my printers, but I understand that it’s not as repeatable as switches.) Speaking of which, is this wired so that sensorless homing can be enabled in software for axes for which it’s OK?
What’s your expectation for how end stops are hooked up? Is it IO0-IO6? If so, are they debounced for mechanical switches? Or would you expect, say, CAN endstops?
Yes, endstops can be connected to input pins in IO0-IO6 (each IO port has an output and input pin). There’s a basic RC network for debouncing.
Speaking of which, is this wired so that sensorless homing can be enabled in software for axes for which it’s OK?
The ‘extra’ control interfaces for the TMC2209 aside from STEP/DIR, which the sensorless homing feature depends on, is wired up to the SAM E5 microcontroller. This is the case for all the five built-in drivers, as well as the two driver expansion.