Rewrite of the Lua DS18B20 module

lua_modules/ds18b20/README.md

@@ -10,45 +10,56 @@ package.loaded["ds18b20"]=nil
 ```
 <a id="ds18b20_setup"></a>
 
-## readTemp()
-Scans the bus for DS18B20 sensors, starts a readout (conversion) for all sensors and calls a callback function when all temperatures are available. Powered sensors are read at once first. Parasite-powered sensors are read one by one. The first parasite-powered sensor is read together with all powered sensors.
+# Methods
 
-The module requires `ow` module.
+## read_temp()
+Scans the bus for DS18B20 sensors (optional), starts a readout (conversion) for all sensors and calls a callback function when all temperatures are available. Powered sensors are read at once first. Parasite-powered sensors are read one by one. The first parasite-powered sensor is read together with all powered sensors.
 
-The also module uses `encoder` module for printing debug information with more readable representation of sensor address (`encoder.toHex()`).
+The module requires `ow` module.
 
 #### Syntax
-`readTemp(callback, pin)`
+`read_temp(callback, pin, unit, force_search, save_search)`
 
 #### Parameters
 - `callback` function that receives all results when all conversions finish. The callback function has one parameter - an array addressed by sensor addresses and a value of the temperature (string for integer version).
 - `pin` pin of the one-wire bus. If nil, GPIO0 (3) is used.
+- `unit` unit can be Celsius ("C" or ds18b20.C), Kelvin ("K" or ds18b20.K) or Fahrenheit ("F" or ds18b20.F). If not specified (nil) latest used unit is used.
+- `force_search` if not nil a bus search for devices is performed before readout. If nil the existing list of sensors in memory is used. If the bus has not been searched yet the search performed as well.
+- `save_search` if not nil found sensors are saved to the file `ds18b20_save.lc`. When `read_temp` is called, list of sensors in memory is empty and file `ds18b20_save.lc` is present then sensor addresses are loaded from file - usefull when running from batteries & deepsleep - immediate readout is performed (no bus scan).
 
 #### Returns
 nil
 
 #### Example
 ```lua
-t = require("ds18b20")
-pin = 3 -- gpio0 = 3, gpio2 = 4
+local t = require("ds18b20")
+local pin = 3 -- gpio0 = 3, gpio2 = 4
 
-function readout(temp)
+local function readout(temp)
+  if t.sens then
+    print("Total number of DS18B20 sensors: ".. #t.sens)
+    for i, s in ipairs(t.sens) do
+      print(string.format("  sensor #%d address: %s%s",  i, ('%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X'):format(s:byte(1,8)), s:byte(9) == 1 and " (parasite)" or ""))
+    end
+  end
   for addr, temp in pairs(temp) do
-    print(string.format("Sensor %s: %s 'C", encoder.toHex(addr), temp))
+    print(string.format("Sensor %s: %s °C", ('%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X'):format(addr:byte(1,8)), temp))
   end
 
   -- Module can be released when it is no longer needed
   t = nil
   package.loaded["ds18b20"]=nil
 end
 
--- t:readTemp(readout) -- default pin value is 3
-t:readTemp(readout, pin)
-if t.sens then
-  print("Total number of DS18B20 sensors: "..table.getn(t.sens))
-  for i, s in ipairs(t.sens) do
-    -- print(string.format("  sensor #%d address: %s%s", i, s.addr, s.parasite == 1 and " (parasite)" or ""))
-    print(string.format("  sensor #%d address: %s%s",  i, encoder.toHex(s.addr), s.parasite == 1 and " (parasite)" or "")) -- readable address with Hex encoding is preferred when encoder module is available
-  end
-end
-```
+t:read_temp(readout, pin, t.C)```
+
+## enable_debug()
+Enables debug output of the module.
+
+# Properties
+
+## sens
+A table with sensors present on the bus. It includes its address (8 bytes) and information whether the sensor is parasite-powered (9-th byte, 0 or 1).
+
+## temp
+A table with readout values (also passed as a parameter to callback function). It is addressed by sensor addresses.

lua_modules/ds18b20/ds18b20-example.lua

@@ -1,26 +1,52 @@
--- encoder module is needed only for debug output; lines can be removed if no
--- debug output is needed and/or encoder module is missing
-
 t = require("ds18b20")
 pin = 3 -- gpio0 = 3, gpio2 = 4
 
-function readout(temp)
+local function readout(temp)
+  if t.sens then
+      print("Total number of DS18B20 sensors: ".. #t.sens)
+      for i, s in ipairs(t.sens) do
+          print(string.format("  sensor #%d address: %s%s",  i, ('%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X'):format(s:byte(1,8)), s:byte(9) == 1 and " (parasite)" or ""))
+      end
+  end
   for addr, temp in pairs(temp) do
-    -- print(string.format("Sensor %s: %s 'C", addr, temp))
-    print(string.format("Sensor %s: %s °C", encoder.toHex(addr), temp)) -- readable address with base64 encoding is preferred when encoder module is available
+    print(string.format("Sensor %s: %s °C", ('%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X'):format(addr:byte(1,8)), temp))
   end
 
   -- Module can be released when it is no longer needed
-  t = nil
-  package.loaded["ds18b20"]=nil
+  --t = nil
+  --package.loaded["ds18b20"]=nil
 end
 
--- t:readTemp(readout) -- default pin value is 3
-t:readTemp(readout, pin)
-if t.sens then
-  print("Total number of DS18B20 sensors: "..table.getn(t.sens))
-  for i, s in ipairs(t.sens) do
-    -- print(string.format("  sensor #%d address: %s%s", i, s.addr, s.parasite == 1 and " (parasite)" or ""))
-    print(string.format("  sensor #%d address: %s%s",  i, encoder.toHex(s.addr), s.parasite == 1 and " (parasite)" or "")) -- readable address with base64 encoding is preferred when encoder module is available
-  end
-end
+t:enable_debug()
+file.remove("ds18b20_save.lc") -- remove saved addresses
+print("=============================================", node.heap())
+print("first call, no addresses in flash, search is performed")
+t:read_temp(readout, pin, t.C) 
+
+tmr.create():alarm(2000, tmr.ALARM_SINGLE, function() 
+    print("=============================================", node.heap())
+    print("second readout, no new search, found addresses are used")
+    t:read_temp(readout, pin) 
+
+tmr.create():alarm(2000, tmr.ALARM_SINGLE, function() 
+    print("=============================================", node.heap())
+    print("force search again")
+    t:read_temp(readout, pin, nil, true) 
+
+tmr.create():alarm(2000, tmr.ALARM_SINGLE, function() 
+    print("=============================================", node.heap())
+    print("save search results")
+    t:read_temp(readout, pin, nil, false, true)
+
+tmr.create():alarm(2000, tmr.ALARM_SINGLE, function() 
+    print("=============================================", node.heap())
+    print("use saved addresses")
+    t.sens={}
+    t:read_temp(readout, pin)
+end)
+
+end)
+
+end)
+
+end)

lua_modules/ds18b20/ds18b20-web.lua

@@ -11,8 +11,7 @@ function readout(temp)
       "<b>ESP8266</b></br>"
 
   for addr, temp in pairs(temp) do
-    -- resp = resp .. string.format("Sensor %s: %s &#8451</br>", addr, temp)
-    resp = resp .. string.format("Sensor %s: %s &#8451</br>", encoder.toHex(addr), temp) -- readable address with base64 encoding is preferred when encoder module is available
+    resp = resp .. string.format("Sensor %s: %s &#8451</br>", ('%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X '):format(addr:byte(1,8)), temp)
   end
 
   resp = resp ..
@@ -30,7 +29,7 @@ srv=net.createServer(net.TCP)
 srv:listen(port,
      function(conn)
         gconn = conn
-        -- t:readTemp(readout) -- default pin value is 3
-        t:readTemp(readout, pin)
+        -- t:read_temp(readout) -- default pin value is 3
+        t:read_temp(readout, pin)
      end
 )