eLua support for GR-SAKURA

I have managed to get eLua running on the GR-SAKURA board. It's an embedded version of version of The Programming Language Lua that can be run on bare-metal.

I forked the original eLua repository and made the necessary changes here on my own copy. Note however that this initial support is very basic; only limited versions of the "tmr", "uart" and "pio" modules are supported at the moment.

Here is an example Lua script that can be run on the board. Name it "autorun.lua" and put it in the "romfs/" directory to run it automatically on startup:

require "pio"
require "pd"
require "tmr"

print("Running LEDs on " .. pd.board())
print("Hold blue button to stop.")

while pio.pin.getval(7) == 1 do
  pio.pin.sethigh(0)
  tmr.delay(0,200000)
  pio.pin.sethigh(1)
  tmr.delay(0,200000)
  pio.pin.sethigh(2)
  tmr.delay(0,200000)
  pio.pin.sethigh(6)
  tmr.delay(0,200000)

  pio.pin.setlow(0)
  tmr.delay(0,200000)
  pio.pin.setlow(1)
  tmr.delay(0,200000)
  pio.pin.setlow(2)
  tmr.delay(0,200000)
  pio.pin.setlow(6)
  tmr.delay(0,200000)
end

print("Finished.")