Activities/Butialo
Butialo is a user-friendly environment that allows programming of the Butiá robot in the Lua language. Lua is a simple imperative scripting language but can create sophisticated programs. It is a dynamic language with automatic memory management and is extremely fast. Butialo is a derivative of the Pippy IDE (Python environment provided with the XO), which simplifies the creation of programs for the presence of components connected to the Butiá and offering snippets of code to access them.
The authoritative documentation is in the Spanish language at [1]
Installation
Download the Activity at [2]
Simple example
Move forward until there is an obstacle.
Motores.setvel2mtr( 1, 500, 1, 500 ) while true do local dist = Dist.getDistancia() if dist<700 then Motores.setvel2mtr( 1, 0, 1, 0 ) repeat wait(1) dist = Dist.getDistancia() until dist > 700 Motores.setvel2mtr( 1, 500, 1, 500 ) end end
Can also be programmed with events. The previous program is equivalent to the following:
local function adelante() -- adelante is Spanish for forward or proceed Motores.setvel2mtr( 1, 500, 1, 500 ) end local function esperar() -- esperar is Spanish for wait Motores.setvel2mtr( 1, 0, 1, 0 ) wait( 1 ) end events.add( Dist.getDistancia, '<', 700, esperar ) events.add( Dist.getDistancia, '>', 700, adelante ) events.go()
Simple example (other)
Butia with dynamic stability. Take a Butiá, remove idler wheels and place an IR distance sensor pointing to the floor. The button toggles the behavior.
local d --measured distance local eq --equilibrium position of d local v --calculated velocity while true do print ("Press the button to start") repeat until Boton.getBoton()==1 eq = Dist.getDistancia() print("Starting", eq) util.wait(1) repeat d = Dist.getDistancia() v = 100+5*math.abs(d-eq) if v > 1024 then v = 1024 end if d < eq then Motores.setvel2mtr(1, v, 1, v) else Motores.setvel2mtr(0, v, 0, v) end until Boton.getBoton()==1 print("Finished") Motores.setvel2mtr(1, 0, 1, 0) util.wait(1) end
Util
Butialo provides various auxiliary functions.
util.wait (t)
Pauses program execution for t seconds.
util.get_time ()
Returns the system time, in seconds.