Add support for Temperature Comparison register set/get functions

lua_modules/lm92/README.md

@@ -1,6 +1,7 @@
 # LM92 module
 This module adds basic support for the LM92 +-0.33C 12bit+sign temperature sensor. More details in the [datasheet](http://www.ti.com/lit/ds/symlink/lm92.pdf).
 Works:
+- 06/01/2016: Add get/set comparison registers. Thyst, Tlow, Thigh and Tcrit
 - getting the temperature
 - entering the chip's to shutdown mode (350uA -> 5uA power consumption)
 - waking up the chip from shutdown
@@ -94,5 +95,181 @@ shutdown()
 ```lua
 LM92.shutdown()
 ```
+
+##setThyst()
+####Description
+Set hysteresis Temperature.
+
+####Syntax
+setThyst(data_wr)
+
+####Parameters
+data_wr: 130~-55 ºC, hysteresis Temperature
+
+####Returns
+nil
+
+####Example
+```lua
+LM92.setThyst(3)
+```
+
+##setTcrit()
+####Description
+Set Critical Temperature.
+
+####Syntax
+setTcrit(data_wr)
+
+####Parameters
+data_wr: 130~-55 ºC, Critical Temperature
+
+####Returns
+nil
+
+####Example
+```lua
+LM92.setTcrit(100.625)
+```
+
+##setTlow()
+####Description
+Set Low Window Temperature.
+
+####Syntax
+setTlow(data_wr)
+
+####Parameters
+data_wr: 130~-55 ºC, Low Window Temperature
+
+####Returns
+nil
+
+####Example
+```lua
+LM92.setTlow(32.25)
+```
+##setThigh()
+####Description
+Set High Window Temperature.
+
+####Syntax
+setThigh(data_wr)
+
+####Parameters
+data_wr: 130~-55 ºC, High Window Temperature
+
+####Returns
+nil
+
+####Example
+```lua
+LM92.setThigh(27.5)
+```
+
+##getThyst()
+####Description
+Get hysteresis Temperature.
+
+####Syntax
+getThyst()
+
+####Parameters
+--
+
+####Returns
+Hysteresis Temperature in degree Celsius.
+
+####Example
+```lua
+t = LM92.getThyst()
+print("Got hysteresis temperature: "..t.." C")
+```
+
+##getTcrit()
+####Description
+Get Critical Temperature.
+
+####Syntax
+getTcrit()
+
+####Parameters
+--
+
+####Returns
+Critical Temperature in degree Celsius.
+
+####Example
+```lua
+t = LM92.getTcrit()
+print("Got Critical temperature: "..t.." C")
+```
+
+##getTlow()
+####Description
+Get Low Window Temperature.
+
+####Syntax
+getTlow()
+
+####Parameters
+--
+
+####Returns
+Low Window Temperature in degree Celsius.
+
+####Example
+```lua
+t = LM92.getTlow()
+print("Got Low Window temperature: "..t.." C")
+```
+
+##getThigh()
+####Description
+Get High Window Temperature.
+
+####Syntax
+getThigh()
+
+####Parameters
+--
+
+####Returns
+High Window Temperature in degree Celsius.
+
+####Example
+```lua
+t = LM92.getThigh()
+print("Got High Window temperature: "..t.." C")
+```
+
+##Full example
+--node.compile("lm92.lua")
+LM92 = require("lm92")
+gpio0 = 3
+gpio2 = 4
+sda = gpio0
+scl = gpio2
+addr = 0x48
+LM92.init(sda, scl,addr)
+ 
+t = LM92.getTemperature()
+print("Got temperature: "..t.." C")
+
+--Seting comparison temperatures
+LM92.setThyst(3)
+LM92.setTcrit(40.75)
+LM92.setTlow(28.5)
+LM92.setThigh(31.625)
+
+t = LM92.getThyst()
+print("Got hyster: "..t.." C")
+t = LM92.getTcrit()
+print("Got Crit: "..t.." C")
+t = LM92.getTlow()
+print("Got Low: "..t.." C")
+t = LM92.getThigh()
+print("Got High: "..t.." C")
+
 #### TODO:
 - add full support of the features, including interrupt and critical alert support

lua_modules/lm92/lm92.lua

@@ -3,6 +3,8 @@
 --
 -- Written by Levente Tamas <levente.tamas@navicron.com>
 --
+-- modify by Garberoglio Leonardo <leogarberoglio@gmail.com> 
+--
 -- GNU LGPL, see https://www.gnu.org/copyleft/lesser.html
 -- ******************************************************
 
@@ -47,6 +49,15 @@ local function write_reg(reg_addr, data)
 	i2c.stop(id)
 end 
 
+--write comparison reg with 2 bytes
+local function write_comp_reg(reg_addr, msb, lsb)
+    i2c.start(id)
+    i2c.address(id, address, i2c.TRANSMITTER)
+    i2c.write(id, reg_addr)
+    i2c.write(id, msb)
+    i2c.write(id, lsb)  
+    i2c.stop(id)
+end 
 -- initialize i2c
 -- d: sda
 -- c: scl
@@ -90,5 +101,96 @@ function M.wakeup()
 	write_reg(0x01,0x00)
 end
 
+-- Write the LM92 Thyst SET POINT
+function M.setThyst(data_wr)
+    local tmp = data_wr / 0.0625
+    if (tmp>=0x1000) then
+        tmp= tmp-0x2000 --convert the two's complement
+    end
+    tmp = bit.lshift(tmp,3)
+    local lsb = bit.band(tmp, 0x00FF)
+    tmp = bit.rshift(bit.band(tmp, 0xFF00),8)
+	write_comp_reg(0x02,tmp, lsb)
+end
 
-return M
+-- Write the LM92 T_crit SET POINT
+function M.setTcrit(data_wr)
+    local tmp = data_wr / 0.0625
+    if (tmp>=0x1000) then
+        tmp= tmp-0x2000 --convert the two's complement
+    end
+    tmp = bit.lshift(tmp,3)
+    local lsb = bit.band(tmp, 0x00FF)
+    tmp = bit.rshift(bit.band(tmp, 0xFF00),8)
+    write_comp_reg(0x03,tmp, lsb)
+end
+
+-- Write the LM92 Tlow SET POINT
+function M.setTlow(data_wr)
+    local tmp = data_wr / 0.0625
+    if (tmp>=0x1000) then
+        tmp= tmp-0x2000 --convert the two's complement
+    end
+    tmp = bit.lshift(tmp,3)
+    local lsb = bit.band(tmp, 0x00FF)
+    tmp = bit.rshift(bit.band(tmp, 0xFF00),8)
+    write_comp_reg(0x04,tmp, lsb)
+end
+
+-- Write the LM92 T_high SET POINT
+function M.setThigh(data_wr)
+    local tmp = data_wr / 0.0625
+    if (tmp>=0x1000) then
+        tmp= tmp-0x2000 --convert the two's complement
+    end
+    tmp = bit.lshift(tmp,3)
+    local lsb = bit.band(tmp, 0x00FF)
+    tmp = bit.rshift(bit.band(tmp, 0xFF00),8)
+    write_comp_reg(0x05,tmp, lsb)
+end
+
+-- Read the LM92 Thyst SET POINT
+function M.getThyst()
+	local temperature
+	local tmp=read_reg(0x02,2) 					--read 2 bytes from the Hysteresis register
+	temperature=bit.rshift(tmp[1]*256+tmp[2],3) --lower 3 bits are status bits
+	if (temperature>=0x1000) then
+		temperature= temperature-0x2000 		--convert the two's complement
+	end
+	return temperature * 0.0625
+end
+
+-- Read the LM92 T_crit SET POINT
+function M.getTcrit()
+	local temperature
+	local tmp=read_reg(0x03,2) 					--read 2 bytes from the T Critical register
+	temperature=bit.rshift(tmp[1]*256+tmp[2],3) --lower 3 bits are status bits
+	if (temperature>=0x1000) then
+		temperature= temperature-0x2000 		--convert the two's complement
+	end
+	return temperature * 0.0625
+end
+
+-- Read the LM92 Tlow SET POINT
+function M.getTlow()
+	local temperature
+	local tmp=read_reg(0x04,2) 					--read 2 bytes from the T Low register
+	temperature=bit.rshift(tmp[1]*256+tmp[2],3) --lower 3 bits are status bits
+	if (temperature>=0x1000) then
+		temperature= temperature-0x2000 		--convert the two's complement
+	end
+	return temperature * 0.0625
+end
+
+-- Read the LM92 T_high SET POINT
+function M.getThigh()
+	local temperature
+	local tmp=read_reg(0x05,2) 					--read 2 bytes from the T High register
+	temperature=bit.rshift(tmp[1]*256+tmp[2],3) --lower 3 bits are status bits
+	if (temperature>=0x1000) then
+		temperature= temperature-0x2000 		--convert the two's complement
+	end
+	return temperature * 0.0625
+end
+
+return M