Application description

AN3260

10/24

Doc ID 17836 Rev 1

3.4

Launching your application from the PC terminal

To display the terminal window, you can either run the preconfigured STM8S-

Discovery_Thermometer.ht terminal based on Windows HyperTerminal (COM1 port) or

At application startup, the user is prompted to enter the minimum and maximum

temperature thresholds. The temperature thresholds must range from −40 to +125 °C, and

be expressed as follows:

G

Positive temperature values: ‘+XXX’. For example enter ‘+025’ for 25 °C.

G

Negative temperature values: ‘−XXX’. For example enter ‘−005’ for −5°C.

Figure 3.

Terminal window at startup

Table 3.

Application typical behaviors

Application

state

LED state

Entry

condition

Actions

State 0

Idle

-

Default

state

Every 50 ms: conversion of analog temperature delivered by the

LM235.

State 1

Config

-

At startup

or when

Button 1

pressed

Informative messages displayed on the terminal window.

User prompted to enter for the first time or to update minimum and

maximum temperature threshold.

State 2

Read

LD1 switched off

Button 2

pressed

Minimum and maximum temperature values read from data

EEPROM and displayed on terminal window

State 3

Normal

-

LD1 switched on if

temperature out

of range

-

-

Every 1 s

–Every 1 s:

Computation of average temperature from 16 samples.

Update of current minimum and maximum temperature values if

needed.

– Every 1 min: display of current temperature value and critical

temperature warning message on the terminal window (if need

be).

– Every 1 hr: minimum and maximum temperature over the previous

hour recorded in data EEPROM.