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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,209 @@ | ||
| -------------------------------------------------------------------------------- | ||
| -- 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 | ||
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||
| 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 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 = {} | ||
|
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||
| local debugPrint = function() return end | ||
|
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||
| -------------------------------------------------------------------------------- | ||
| -- 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) | ||
|
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||
| 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) | ||
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||
| if unit == 'F' then | ||
| t = (t * 18)/10 + 320000 | ||
| elseif unit == 'K' then | ||
| t = t + 2731500 | ||
| end | ||
| local sgn = t<0 and -1 or 1 | ||
| local tA = sgn*t | ||
| local tH=tA/10000 | ||
| local tL=(tA%10000)/1000 + ((tA%1000)/100 >= 5 and 1 or 0) | ||
|
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| if tH and (t~=850000) then | ||
| debugPrint(to_string(addr),(sgn<0 and "-" or "")..tH.."."..tL, 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 | ||
|
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||
| 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) | ||
|
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||
| 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 | ||
|
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| 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 | ||
|
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||
| 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") | ||
|
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||
| 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 | ||
|
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||
| -- 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 |
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