I am looking at developing firmware to extend embedded systems that communicate via Serial.
So I decided to ask before just starting.(I searched online but could not find anything related)
This is what I am looking for:
I am developing shields for GRBL(CNC software - G-Code interpreter). Currently GRBL only communicates through to the serial port of an Arduino UNO. GRBL does what it does very well, but we are running out of memory and I/O pins on an standard UNO board. So my goaI is to extend it...
I recently developed a general purpose shield that adds an extra ATMega328(info.protoneer.com/2).
With this shield I want to run GRBL on it and use the Arduino UNO as a Serial proxy.
The Serial proxy will accept commands,inspect them and forward GRBL compatible commands to the MCU with GRBL installed.
By having this extra layer we can extend the list of commands a GRBL setup can understand. This also give us the opportunity
to add extended commands that can be forwarded to I2C devices.(Huge advantage)
Does anyone know if there is already an existing system/setup that can do the above?
but we are running out of memory and I/O pins on an standard UNO board.
I/O pins are no problem, a port expander chip or two will soon solve that. Memory is another issue however.
Rather than have two processors, which is rarely a good idea, why not use a bigger processor like an ATmega 644 or one of the Mega board processors like the 1280. Finally if that is not enough why not go for an Arduino Due?
Grumpy_Mike:
I/O pins are no problem, a port expander chip or two will soon solve that. Memory is another issue however.
Rather than have two processors, which is rarely a good idea, why not use a bigger processor like an ATmega 644 or one of the Mega board processors like the 1280. Finally if that is not enough why not go for an Arduino Due?
All valid options. But...
Arduino Mega's and Due's are to expensive for most projects I would say... Using a non-standard MCU vs a widely available MCU like the UNO also has its draw backs.
That's why I thought the Serial Proxy might be a very convenient way of keeping things backward compatible but still plug and play.
If you're dealing with a CNC solution this implies a considerable investment of time and money - it seems odd to me that a few bucks difference in the cost of a different Arduino model would be a factor. If this is to be a product, it seems odd to me that you'd be wanting to use a standard Arduino at all.
