blob: 5b8a2476d142e4f300430a7abd4e53097850d9a1 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
local device = _G
local GET_VALUE=string.char(0x00)
local string_byte=string.byte
-- description: lets us know dist sensor's current value
-- input: empty
-- output: dist sensor's current value.
api={}
api.getValue = {}
api.getValue.parameters = {} -- no input parameters
api.getValue.returns = {[1]={rname="par1", rtype="int"}}
api.getValue.call = function ()
device:send(GET_VALUE) -- operation code 1 = get distance of object
local sen_anl_response = device:read(3) -- operation code and data
if not sen_anl_response or #sen_anl_response~=3 then return -1 end
--local raw_val = (string_byte(sen_anl_response, 2) or 0) + (string_byte(sen_anl_response, 3) or 0)* 256
raw_val = string.byte(sen_anl_response, 2)* 256 + string.byte(sen_anl_response, 3)
raw_val = 1024 - raw_val
return raw_val
end
|
