UM1542 datasheet(22/43 Pages) STMICROELECTRONICS

22 / 43 page

Using the STEVAL-IHT001V2 thermostat kit

UM1542

22/43

Doc ID 023172 Rev 1

3.6.3

Force debug

A “force debug” is used to force the AC load state to the control state as defined by the MCU

for easier board validation (Figure 9). In order to control the AC loads, it is necessary to click

on the “Debug Active” button in the “Debug Mode” frame. In this case, the green lights of the

AC load buttons are on if the associated loads are also on. Otherwise, the user can pre-

select the load to be switched on, before clicking on the “Debug Active” push button, in

which case the buttons corresponding to the pre-selected load become yellow, but this has

no effect until the “Debug Active” button is pushed.

If the debug mode is active (“Debug” push button is lit), then:

●

Clicking on the “Compressor/Fan” button turns on Q1 and Q3, i.e. the compressor and

fan.

●

Clicking on the “Light Bulb” button turns on Q4, and then the bulb lights up.

●

Clicking on the “Defrost” button turns on Q2, and then the defrost resistor starts to heat.

Note:

The defrost and compressor loads cannot be switched on at the same time. Setting defrost

resets compressor, and vice-versa.

The light bulb and fan cannot be switched on at the same time. The fan switches off as soon

as the light bulb switches on.

In order to go back to the “normal” mode, the user must click on the “Debug” button. In this

case, all the virtual button green lights turn off.

Figure 9.

GUI - debug mode frame

3.6.4

Parameter measurements

The GUI is able to get and display the different parameters from the MCU, like the

temperature order, the evaporator temperature, the AC load state, the compressor cycle

information (running period and duty cycle) and the mains frequency.

For more information refer to the “Help” menu of GUI software.

To enable real-time data acquisition, the user must push on the “Start Acquisition” button

(refer to the “Help” menu of the GUI software for more information). The sampling frequency

can be set in the “Options” window.

UM1542 Datasheet(PDF) 22 Page - STMicroelectronics