use _SOCK_CMD_LEN=16 as in pigpio.py

Author: Alexander-Barth

src/constants.jl

@@ -57,6 +57,8 @@ WAVE_MODE_REPEAT_SYNC  =3
 WAVE_NOT_FOUND = 9998 # Transmitted wave not found.
 NO_TX_WAVE     = 9999 # No wave being transmitted.
 
+_SOCK_CMD_LEN = 16
+
 # pigpio command numbers
 
 _PI_CMD_MODES= 0

src/pi.jl

@@ -104,7 +104,7 @@ Runs a pigpio socket command.
 function _pigpio_command(sl::SockLock, cmd::Integer, p1::Integer, p2::Integer, rl=true)
     lock(sl.l)
     Base.write(sl.s, UInt32.([cmd, p1, p2, 0]))
-    out = IOBuffer(Base.read(sl.s, 16))
+    out = IOBuffer(Base.read(sl.s, _SOCK_CMD_LEN))
     msg = reinterpret(Cuint, take!(out))[4]
     if rl
         unlock(sl.l)