WARNING: This repository is still work in progress. The following are just propose functionalities.

LED ring for Marlin Delta

The LED ring interface for Marlin Delta firmware. It contains 16 RGB LEDs controlled by Arduino Pro Mini. Arduino Mega 2560 communicate with Arduino Pro Mini via one of its USART serial. Mega can either controlling LEDs from Mini Pro or updating firmware in it. Been doing this way could not only allow updating firmware in both Mega and Pro Mini also could do functional tests by only using the USB port on Mega.

Sequence Diagram

Pins Swap

Original RAMP 1.4 Pinouts

ATMEGA Pins	Functions	PORT	NAME	Digital/Analog	Arduino Pin	Arduino Name	Purpose
2	RXD0	PE0	RXD0/PCINT8	Digital	pin 0	RX0	Serial over usb
3	TXD0	PE1	TXD0	Digital	pin 1	TX0	Serial over usb
45	RXD1	PD2	RXD1/INT2	Digital	pin 19	RX1	Z-MAX
46	TXD1	PD3	TXD1/INT3	Digital	pin 18	TX1	Z-MIN
12	RXD2	PH0	RXD2	Digital	pin 17	RX2	on aux4
13	TXD2	PH1	TXD2	Digital	pin 16	TX2	on aux4
63	RXD3	PJ0	RXD3/PCINT9	Digital	pin 15	RX3	Y-MAX
64	TXD3	PJ1	TXD3/PCINT10	Digital	pin 14	TX3	Y-MIN

Need to define following in Marlin "Configuration.h" header file to free up pins for serial port connected to Arduino Pro Mini.

#define DISABLE_MIN_ENDSTOPS

Then swap Z-MAX pin 19 to Y-MIN pin 14 as follow.

#define Z_MAX_PIN	14

This will leave pin 19 and 18 free for use with Arduino Pro Mini for LED-Ring serial interface. Z-MIN pin 18 is also used for autoleveling. Since auto leveling is only used when Arduino Mega is running it should not effect by this change. Now the pinouts changed as below.

ATMEGA Pins	Functions	PORT	NAME	Digital/Analog	Arduino Pin	Arduino Name	Purpose
2	RXD0	PE0	RXD0/PCINT8	Digital	pin 0	RX0	Serial over usb
3	TXD0	PE1	TXD0	Digital	pin 1	TX0	Serial over usb
45	RXD1	PD2	RXD1/INT2	Digital	pin 19	RX1	LED-Ring Controller
46	TXD1	PD3	TXD1/INT3	Digital	pin 18	TX1	LED-Ring Controller or Z-MIN/Autolevel
12	RXD2	PH0	RXD2	Digital	pin 17	RX2	on aux4
13	TXD2	PH1	TXD2	Digital	pin 16	TX2	on aux4
63	RXD3	PJ0	RXD3/PCINT9	Digital	pin 15	RX3	Y-MAX
64	TXD3	PJ1	TXD3/PCINT10	Digital	pin 14	TX3	Z-MAX

The Marlin firmware needs to be modified with existing or new g-code to pass data to TX1/RX1 port. This g-code also needs to control the Marlin modes (Normal running & Pass-Through) to communicate with Arduino Pro Mini LED-Ring controller. The communication protocol between Arduino Mega running Marlin and Arduino Pro Mini LED-Ring controller still yet to be defined.

Arduino remote programming

Check in following repo.

Arduino Remote Upload