207 lines
6.8 KiB
Lua
207 lines
6.8 KiB
Lua
--------------------------------------------------------------------------------
|
|
-- DS18B20 one wire module for NODEMCU
|
|
-- NODEMCU TEAM
|
|
-- LICENCE: http://opensource.org/licenses/MIT
|
|
-- @voborsky, @devsaurus, TerryE 26 Mar 2017
|
|
--------------------------------------------------------------------------------
|
|
local modname = ...
|
|
|
|
-- Used modules and functions
|
|
local type, tostring, pcall, ipairs =
|
|
type, tostring, pcall, ipairs
|
|
-- Local functions
|
|
local ow_setup, ow_search, ow_select, ow_read, ow_read_bytes, ow_write, ow_crc8,
|
|
ow_reset, ow_reset_search, ow_skip, ow_depower =
|
|
ow.setup, ow.search, ow.select, ow.read, ow.read_bytes, ow.write, ow.crc8,
|
|
ow.reset, ow.reset_search, ow.skip, ow.depower
|
|
|
|
local node_task_post, node_task_LOW_PRIORITY = node.task.post, node.task.LOW_PRIORITY
|
|
local string_char, string_dump = string.char, string.dump
|
|
local now, tmr_create, tmr_ALARM_SINGLE = tmr.now, tmr.create, tmr.ALARM_SINGLE
|
|
local table_sort, table_concat = table.sort, table.concat
|
|
local math_floor = math.floor
|
|
local file_open = file.open
|
|
local conversion
|
|
|
|
local DS18B20FAMILY = 0x28
|
|
local DS1920FAMILY = 0x10 -- and DS18S20 series
|
|
local CONVERT_T = 0x44
|
|
local READ_SCRATCHPAD = 0xBE
|
|
local READ_POWERSUPPLY= 0xB4
|
|
local MODE = 1
|
|
|
|
local pin, cb, unit = 3
|
|
local status = {}
|
|
|
|
local debugPrint = function() return end
|
|
|
|
--------------------------------------------------------------------------------
|
|
-- Implementation
|
|
--------------------------------------------------------------------------------
|
|
local function enable_debug()
|
|
debugPrint = function (...) print(now(),' ', ...) end
|
|
end
|
|
|
|
local function to_string(addr, esc)
|
|
if type(addr) == 'string' and #addr == 8 then
|
|
return ( esc == true and
|
|
'"\\%u\\%u\\%u\\%u\\%u\\%u\\%u\\%u"' or
|
|
'%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X '):format(addr:byte(1,8))
|
|
else
|
|
return tostring(addr)
|
|
end
|
|
end
|
|
|
|
local function readout(self)
|
|
local next = false
|
|
local sens = self.sens
|
|
local temp = self.temp
|
|
for i, s in ipairs(sens) do
|
|
if status[i] == 1 then
|
|
ow_reset(pin)
|
|
local addr = s:sub(1,8)
|
|
ow_select(pin, addr) -- select the sensor
|
|
ow_write(pin, READ_SCRATCHPAD, MODE)
|
|
local data = ow_read_bytes(pin, 9)
|
|
|
|
local t=(data:byte(1)+data:byte(2)*256)
|
|
-- t is actually signed so process the sign bit and adjust for fractional bits
|
|
-- the DS18B20 family has 4 fractional bits and the DS18S20s, 1 fractional bit
|
|
t = ((t <= 32767) and t or t - 65536) *
|
|
((addr:byte(1) == DS18B20FAMILY) and 625 or 5000)
|
|
local crc, b9 = ow_crc8(string.sub(data,1,8)), data:byte(9)
|
|
|
|
t = t / 10000
|
|
if math_floor(t)~=85 then
|
|
if unit == 'F' then
|
|
t = t * 18/10 + 32
|
|
elseif unit == 'K' then
|
|
t = t + 27315/100
|
|
end
|
|
debugPrint(to_string(addr), t, crc, b9)
|
|
if crc==b9 then temp[addr]=t end
|
|
status[i] = 2
|
|
end
|
|
end
|
|
next = next or status[i] == 0
|
|
end
|
|
if next then
|
|
node_task_post(node_task_LOW_PRIORITY, function() return conversion(self) end)
|
|
else
|
|
--sens = {}
|
|
if cb then
|
|
node_task_post(node_task_LOW_PRIORITY, function() return cb(temp) end)
|
|
end
|
|
end
|
|
end
|
|
|
|
conversion = (function (self)
|
|
local sens = self.sens
|
|
local powered_only = true
|
|
for _, s in ipairs(sens) do powered_only = powered_only and s:byte(9) ~= 1 end
|
|
if powered_only then
|
|
debugPrint("starting conversion: all sensors")
|
|
ow_reset(pin)
|
|
ow_skip(pin) -- skip ROM selection, talk to all sensors
|
|
ow_write(pin, CONVERT_T, MODE) -- and start conversion
|
|
for i, _ in ipairs(sens) do status[i] = 1 end
|
|
else
|
|
local started = false
|
|
for i, s in ipairs(sens) do
|
|
if status[i] == 0 then
|
|
local addr, parasite = s:sub(1,8), s:byte(9) == 1
|
|
if parasite and started then break end -- do not start concurrent conversion of powered and parasite
|
|
debugPrint("starting conversion:", to_string(addr), parasite and "parasite" or "")
|
|
ow_reset(pin)
|
|
ow_select(pin, addr) -- select the sensor
|
|
ow_write(pin, CONVERT_T, MODE) -- and start conversion
|
|
status[i] = 1
|
|
if parasite then break end -- parasite sensor blocks bus during conversion
|
|
started = true
|
|
end
|
|
end
|
|
end
|
|
tmr_create():alarm(750, tmr_ALARM_SINGLE, function() return readout(self) end)
|
|
end)
|
|
|
|
local function _search(self, lcb, lpin, search, save)
|
|
self.temp = {}
|
|
if search then self.sens = {}; status = {} end
|
|
local sens = self.sens
|
|
pin = lpin or pin
|
|
|
|
local addr
|
|
if not search and #sens == 0 then
|
|
-- load addreses if available
|
|
debugPrint ("geting addreses from flash")
|
|
local s,check,a = pcall(dofile, "ds18b20_save.lc")
|
|
if s and check == "ds18b20" then
|
|
for i = 1, #a do sens[i] = a[i] end
|
|
end
|
|
debugPrint (#sens, "addreses found")
|
|
end
|
|
|
|
ow_setup(pin)
|
|
if search or #sens == 0 then
|
|
ow_reset_search(pin)
|
|
-- ow_target_search(pin,0x28)
|
|
-- search the first device
|
|
addr = ow_search(pin)
|
|
else
|
|
for i, _ in ipairs(sens) do status[i] = 0 end
|
|
end
|
|
local function cycle()
|
|
if addr then
|
|
local crc=ow_crc8(addr:sub(1,7))
|
|
if (crc==addr:byte(8)) and ((addr:byte(1)==DS1920FAMILY) or (addr:byte(1)==DS18B20FAMILY)) then
|
|
ow_reset(pin)
|
|
ow_select(pin, addr)
|
|
ow_write(pin, READ_POWERSUPPLY, MODE)
|
|
local parasite = (ow_read(pin)==0 and 1 or 0)
|
|
sens[#sens+1]= addr..string_char(parasite)
|
|
status[#sens] = 0
|
|
debugPrint("contact: ", to_string(addr), parasite == 1 and "parasite" or "")
|
|
end
|
|
addr = ow_search(pin)
|
|
node_task_post(node_task_LOW_PRIORITY, cycle)
|
|
else
|
|
ow_depower(pin)
|
|
-- place powered sensors first
|
|
table_sort(sens, function(a, b) return a:byte(9)<b:byte(9) end) -- parasite
|
|
-- save sensor addreses
|
|
if save then
|
|
debugPrint ("saving addreses to flash")
|
|
|
|
local addr_list = {}
|
|
for i =1, #sens do
|
|
local s = sens[i]
|
|
addr_list[i] = to_string(s:sub(1,8), true)..('.."\\%u"'):format(s:byte(9))
|
|
end
|
|
local save_statement = 'return "ds18b20", {' .. table_concat(addr_list, ',') .. '}'
|
|
debugPrint (save_statement)
|
|
local save_file = file_open("ds18b20_save.lc","w")
|
|
save_file:write(string_dump(loadstring(save_statement)))
|
|
save_file:close()
|
|
end
|
|
-- end save sensor addreses
|
|
if lcb then node_task_post(node_task_LOW_PRIORITY, lcb) end
|
|
end
|
|
end
|
|
cycle()
|
|
end
|
|
|
|
local function read_temp(self, lcb, lpin, lunit, force_search, save_search)
|
|
cb, unit = lcb, lunit or unit
|
|
_search(self, function() return conversion(self) end, lpin, force_search, save_search)
|
|
end
|
|
|
|
-- Set module name as parameter of require and return module table
|
|
local M = {
|
|
sens = {},
|
|
temp = {},
|
|
C = 'C', F = 'F', K = 'K',
|
|
read_temp = read_temp, enable_debug = enable_debug
|
|
}
|
|
_G[modname or 'ds18b20'] = M
|
|
return M
|