W1209 Digital Temperature Controller Thermostat Module

W1209 digital temperature controller module is a low cost and highly functional thermostat module which is widely used in automation projects. W1209 thermostat module includes a seven segment LED display and a NTC waterproof temperature sensor. There are 3 switches (SET, + and -) on board to set temperature and other parameters like turning on trigger temperature. W1209 module has an integrated microcontroller in it but does not requires  programming knowledge. There is an onboard relay which acts as a switch to the load connected to it. A maximum load of 240V AC at 5A or 14V DC at 10A can be connected to the on board relay. Measurement and control accuracy of the circuit is 0.1° C. Temperature control range for the module is -50° C to 110° C. 0.5 seconds is the refresh rate of the W1209 module. 

Displaying the current temperature
The thermostat will display the current temperature in °C by default. When in any other mode making no input for approximately 5 seconds will cause the thermostat to return to this default display.
Setting the trigger temperature.
To set the trigger temperature, press the button marked ‘SET’. The seven-segment display will flash. You can now set a trigger temperature (in °C) using the ‘+’ and ‘-‘ buttons in 0.1° increments. If we don’t press any buttons for approximately 2 seconds, the trigger temperature will be stored, and the display will return back to the current temperature.
Setting the parameters
To set any parameter, first long-press the ‘SET’ button for at least 5 seconds. The seven-segment display should now display ‘P0’. This represents parameter P0. Pressing the ‘+’ or ‘-‘ buttons will cycle through the various parameters (P0 to P6). Pressing the ‘SET’ button whilst any of these parameters are displayed will allow you to change the value for that parameter using the ‘+’ and ‘-‘ buttons. When finished setting a parameter, press the set button to exit that option. If no buttons are pressed for approximately 5 seconds, the thermostat will exit the parameter options and will return back to the default temperature display.
Setting the cooling or heating parameter P0
The parameter P0 has two settings, C and H. When setting to C (default), the relay will energize when the temperature is reached. Use this setting if connecting to an air-conditioning system. When set to H, the relay will de-energize when the temperature is reached. Use this setting if controlling a heating device.
Setting the hysteresis parameter P1
This sets how much change in temperature must occur before the relay changes state. For example, if set to the default 2oC and the trigger temperature has been set to 25oC, it will not de-energize until the temperature falls back below 23oC. Setting this hysteresis helps stop the thermostat from continually triggering when the temperature drifts around the trip temperature.
Setting the upper limit of the thermostat parameter P2
This parameter limits the maximum trigger temperature that can be set. It is useful as a safety to stop an excessively high trigger temperature from accidentally being set by the user.
Setting the lower limit of the thermostat parameter P3
This parameter limits the minimum trigger temperature that can be set. It is useful as a safety to stop an excessively low trigger temperature from accidentally being set by the user.
Setting temperature offset correction parameter P4
Should you find, there is a difference between the displayed temperature and the actual temperature; (for instance, if the temperature probe is on a long run of cable) you can make minor corrections to the temperature reading with this parameter.
Setting the trigger delay parameter P5
To reach trigger temperature, this parameter allows for delaying the switching of the relay. The parameter can be set in one-minute increments up to a maximum of 10 minutes.
Setting the high temperature alarm parameter P6
Setting a value for this parameter will cause the relay to switch off when the temperature reaches this setting. The seven-segment display will also show ‘—‘ to indicate an alarm condition. The relay will not re-energize until the temperature falls below this value. The default setting is OFF.

 Specifications

Further Info

W1209 is a temperature control module, especially a thermostat control module, that allows us to intelligently manage the temperature in our immediate environment. It accomplishes this by using a relay attached to an electronic or electrical device. The module contains seven modes, each of which may be configured by following specific processes that will be detailed later. The module is powered by a 12V DC source. It may be used in a variety of automation projects and can be designed to be used in various applications.