Advertisement  

Saturday, 28 March 2020
     
 
Main Menu
Home Home
Shop Shop
News News
BASCOM-AVR BASCOM-AVR
BASCOM-8051 BASCOM-8051
Products Products
Application Notes Application Notes
Publications Publications
Links Links
Support Center Support Center
Downloads Downloads
Forum Forum
Resellers Resellers
Contact Us Contact Us
Updates Updates
MCS Wiki MCS Wiki
Online Help
BASCOM-AVR Help BASCOM-AVR Help
BASCOM-8051 Help BASCOM-8051 Help
Contents in Cart
Show Cart
Your Cart is currently empty.
Search the Shop

Products Search

User Login
Username

Password

If you have problem after log in with disappeared login data, please press F5 in your browser

RSS News
 
     
 

 
   
     
 
AN #191 - Thermometer Print
Thermometer, thermostat with Temperature - 0.1C, range of supported temperatures of - 55 to +125 C
by Peter

This thermometer-thermostat allows you to measure and maintain a temperature of -55 C to +125 C, with an accuracy of 0.1 C. It is built on a microcontroller ATmega8, digital temperature sensor DS18B20 and character display, on the basis of the controller HD44780, containing 2 lines of 16 characters each. Originally it was designed to manage the incubator, but after some changes in the program the microcontroller, the range of supported temperatures was significantly expanded.

In standard mode, the screen displays the current temperature, which is updated every second. Pressing the button SB1, supported by a temperature controller displays the temperature on the bottom line display. Long-term, continuous press of the button SB2 (the data of seconds specified in the constant "Button_mode_time", by default - 4 seconds) will transfer the unit to service mode, you can set a new value of the temperature. In this mode, the button SB1 increases the value of the temperature, and the SB2 - decreases. Long press (time in seconds, depending on the number of constant Button_force_time) on one of these buttons lead to a rapid change in temperature. Writing a new value of the temperature will automatically after a certain period of time specified in the constant "Thermo_mode_save_time" (by default - 8 seconds) if no button is pressed.

The thermostat can operate on heating (eg, in an incubator) and cooling (eg, in the refrigerator). The mode is selected by using the constant "Thermostat_type". As originally developed the device to maintain the temperature in the incubator and the reliability was very important, then it has been added sound notification or absence of fault (or broken wire) sensor. If you repeatedly fail to read data from the sensor DS18B20, then from the speaker you hear an alarm. If necessary, disable this option easily, by writing to the constant "Error_sound_state" number not equal to one. The same speaker is used for scoring buttons. If that does not require a constant "Button_beep_state" need not record the number of 1.




Source code:


'*****************************************************************************
'**            Thermometer, thermostat with Temperature - 0.1C             **
'**          The range of supported temperatures of - 55 to +125 C         **
'**   Compiler - BASCOM v 2.0.1.0; Ńontroller - ATmega8; Sensor - DS18B20   **
'**   Author - Peter                                           24.11.2010ă. **
'*****************************************************************************

$regfile = "m8def.dat" ' ATmega8
$crystal = 4000000                                          ' 4 ĚĂö

$hwstack = 80
$swstack = 80
$framesize = 80

Declare Sub Mk_init()
Declare Sub Selectmode()
Declare Sub Thermo_lcd(thermo As Integer)
Declare Sub Thermocontrol(thermo As Integer , Thermosetting As Integer)
Declare Sub Modify_setting_button()
Declare Sub Modify_setting_lcd(thermo As Integer)
Declare Function Read_thermo(thermo As Byte) As Byte

1wire_pin Alias Portd.0                                     ' The output for the sensor DS18B20.
Button_plus Alias Pind.1                                    ' Button "+ / current temperature".
Button_minus Alias Pind.2                                   ' Button "- / settings".
Led_read_1wire Alias Portc.0                                ' The output for the LED blinks when data is read from the sensor DS18B20.
Out_thermostat Alias Portc.1                                ' Output the thermostat. It connects the load.
Sreaker Alias Portc.2                                       ' Output to the speaker.

Const Button_delay = 24
Const Button_force_delay = 200                              ' The delay in milliseconds. change in long-term retention of digits in service mode buttons.
Const Thermostat_type = 0                                   ' 0 - thermostat operates in heating, 1 - Cooling.
Const Error_sound_state = 1                                 ' 1 - beep if an error occurs reading data from the sensor DS18B20.
Const Button_force_time = 2                                 ' Time in seconds after which to begin a rapid change in the current setting temperature.
Const Thermo_mode_save_time = 8                             ' đĺě˙  ńĺęäŕő, ď ďđřĺńňčţ ęňđă, äň ŕďčńŕű äŕűĺ  ňĺęůĺ ňĺěďĺđŕňđĺ, ĺńč ĺ ŕćčěŕŕńü č äŕ ęďęŕ.
Const Button_beep_state = 1                                 ' 1 - čŕňü ęŕčŕňđ
Const Button_mode_time = 4                                  ' Time in seconds, after which will be recorded in the EEPROM data on the current temperature, if not clicked no button.

Dim Flaginputtermo As Byte ' 1 - the need to poll the sensor DS18B20.
Dim Thermo_mode_state As Byte ' The auxiliary variable used in the translation unit in setting mode.
Dim Button_plus_state As Byte ' The auxiliary variable used in determining when press / release the "+ / current temperature" in service mode.
Dim Button_minus_state As Byte ' The auxiliary variable used in determining when press / release button "- / settings" in the mode.
Dim Button_force_counter As Byte ' Time counter (seconds), after which begins a rapid change in temperature in the installed mode.
Dim Temp_1wirearray(9) As Byte ' In this array of data from the sensor is placed DS18B20
Dim 1wire_array(9) As Byte ' and if no errors, then the data is copied into the array.
Dim Error_thermo_counter As Byte ' Error counter reading from the sensor DS18B20.
Dim Thermo_mode As Byte ' Working hours: 0 - normal operation, 1 - preparing for the transition to a service mode 2 - mode settings.
Dim Thermo_mode_counter As Byte ' Counter counting down the time (in seconds) required to switch to the settings.
Dim Thermo_mode_save_counter As Byte ' Counter, after which the settings will be saved in EEPROM.
Dim Currenttermo As Integer At 1wire_array Overlay ' Current temperature.
Dim Thermo_setting As Integer ' Supported by the thermostat temperature.
Dim Modify_thermo_setting As Integer ' Time value maintained by the thermostat temperature to be used in service mode.
Dim Ee_thermosetting As Eram Integer ' Memory location in EEPROM, which stores the current temperature is maintained.


Config Lcd = 16 * 2                                         ' Display 2 lines of 16 characters.
Config Lcdbus = 4
Config Lcdmode = Port
Config Lcdpin = Pin , Db4 = Portb., Db5 = Portb., Db6 = Portb., Db7 = Portb., Rs = Portb., E = Portb.5
Config 1wire = 1wire_pin                                    ' The configuration pin of the temperature sensor DS18B20.
Config Led_read_1wire = Output ' The configuration pin output for the LED blinks when data is read from the sensor.
Config Out_thermostat = Output ' The configuration pin for the thermostat output.
Config Sreaker = Output ' The configuration pin for output to speaker, the sender of an emergency.
Config Button_plus = Input ' The configuration pin for the "+ / current temperature".
Config Button_minus = Input ' Configuration pin for a button "- / settings".
Config Timer1 = Timer , Prescale = 64                       ' The configuration of the timer Timer1.
On Timer1 Timer1_interrupts
Stop Timer1

Config Watchdog = 2048                                      ' The configuration of the watchdog response time of about 2 seconds.


Call Mk_init()
Enable Interrupts ' Enable all interrupts.



'************************** Main ***********************************************

Do
 Reset Watchdog ' Reset watchdog.
 If Flaginputtermo = 1 Then ' Needs to read data from the sensor DS18B20.
     Flaginputtermo = 0
 If Read_thermo(1wire_array(1)) = 1 Then ' Successful reading of data from the sensor DS18B20.
 If Thermo_mode = 0 Then
 Call Thermo_lcd(currenttermo) ' The output of the current temperature display.
 End If
 Call Thermocontrol(currenttermo , Thermo_setting) ' Comparison of current and set temperature and load management.
       Error_thermo_counter = 0                             ' Reset error counter is read from the sensor DS18B20.
 Else ' An error occurred while reading data from the sensor.
 If Error_thermo_counter >= 2 Then
 #if Error_sound_state = 1
 Sound Sreaker , 2000 , 80                        ' Alarm.
           Sreaker = 0
 #endif
         Sreaker = 0
         Error_thermo_counter = 0
 Cls : Lcd "Sensor error!"
         Thermo_mode = 0
 Else
 Incr Error_thermo_counter                           ' If an error occurred reading from DS18B20, but do not exceed the allowable threshold of errors - errors increase the value of the counter.
 End If
 End If
 End If

 Call Selectmode() ' Poll button and switch modes.

 If Thermo_mode = 2 Then ' Settings mode.
 Call Modify_setting_button()
 End If

Loop
End


' ***************************** Interrupts *************************************

' Interrupt Timer1 (interrupt occurs approximately once per second).
Timer1_interrupts:
   Flaginputtermo = 1                                       ' Necessary to interrogate the sensor DS18B20.
 If Thermo_mode = 0 And Thermo_mode_state = 1 Then ' Button is pressed and held the entrance to the settings.
 If Thermo_mode_counter < 200 Then Incr Thermo_mode_counter       ' Counting the time interval required to enter settings.
 Elseif Thermo_mode = 2 Then ' Active mode settings.
 If Thermo_mode_save_counter < 200 Then Incr Thermo_mode_save_counter       ' Counter time before saving settings.
 If Button_force_counter < 200 Then Incr Button_force_counter       ' Counter times out quickly change the desired temperature for prolonged holding down the button.
 End If
Return



' **************************** Subroutine **************************************

' Initialization program.
Sub Mk_init()
 Out_thermostat = 0
 Sreaker = 0
 Error_thermo_counter = 0
 Thermo_mode = 0
 Thermo_mode_state = 0
 Thermo_mode_counter = 0
 Thermo_mode_save_counter = 0
 Thermo_setting = Ee_thermosetting                          ' Reading a given temperature from EEPROM memory.

 Cursor Off
 Deflcdchar 1 , 228 , 234 , 228 , 224 , 224 , 224 , 224 , 224       ' Symbol ""
 Cls
 Lcd "Thermostat v 1.2"
 Lowerline
 'Lcd "BASCOM v 2.0.1.0"
 Lcd "Lev-hik@yandex.ru"

 If Thermo_setting < -880 Or Thermo_setting > 2000 Then ' These temperatures are not supported.
 #if Error_sound_state = 1
 Sound Sreaker , 2000 , 80                              ' Alarm.
     Sreaker = 0
 #endif
 Cls
 Lcd "Error EEPROM"
   Thermo_setting = 0                                       ' Set of the temperature of 0  C.
   Ee_thermosetting = Thermo_setting                        ' Save the data in the EEPROM.
 End If

 1wreset ' Reset sensor.
 1wwrite &HCC                                               ' Command "Skip ROM".
 1wwrite &H44                                               ' Command "Convert  T"

 Wait 2
 Shiftlcd Left
 Wait 1
 Timer1 = 0
 Flaginputtermo = 0
 Enable Timer1
 Start Timer1
 Start Watchdog
End Sub



' Subroutine mode selection.
Sub Selectmode()
 If Thermo_mode = 0 Then ' Standard mode.
 If Button_minus = 0 Then

 #if Button_beep_state = 1
 If Button_minus_state = 0 Then
 Waitms Button_delay
 If Button_minus = 0 Then
             Button_minus_state = 1
 Sound Sreaker , 80 , 400
             Sreaker = 0
 Else
            Button_minus_state = 0
 End If
 End If
 #endif

 If Thermo_mode_state = 0 Then
         Thermo_mode_counter = 0
         Thermo_mode_state = 1
 Else
 If Thermo_mode_counter >= Button_mode_time Then Thermo_mode = 1       ' Long-term (defined in a constant Button_mode_time) holding down button "- / settings" - preparing to move into the service mode.
 End If
 Else
       Thermo_mode_counter = 0
       Thermo_mode_state = 0
       Button_minus_state = 0
 End If
 Else ' Mode settings.

 If Thermo_mode_state = 1 Then
       Thermo_mode_counter = 0
       Thermo_mode_state = 0
 Cls
 Lcd Spc(4) ; "Setting"
 End If

 If Thermo_mode = 1 Then ' Preparing to move into the service mode (standby button is released "- / settings").
 If Button_minus = 1 Then
 Waitms Button_delay
 If Button_minus = 1 Then
           Thermo_mode = 2                                  ' Button "- / settings" is released - go to service mode.
           Modify_thermo_setting = Thermo_setting
           Thermo_mode_save_counter = 0
           Button_plus_state = 0
           Button_minus_state = 0
 Call Modify_setting_lcd(modify_thermo_setting)
 End If
 End If
 Elseif Thermo_mode > 2 Then ' BUG!
       Thermo_mode = 0
       Thermo_mode_counter = 0
       Thermo_mode_state = 0
       Button_plus_state = 0
       Button_minus_state = 0
 End If

 End If
End Sub




' Subroutine service keys in selection of the temperature.
Sub Modify_setting_button()
 Local Temp_shift As Byte
 Local Temp_1 As Byte

 If Button_plus = 0 And Button_minus = 1 Then ' Press "+ / current temperature".
 Waitms Button_delay
 If Button_plus = 0 Then
         Thermo_mode_save_counter = 0
 If Button_force_counter >= Button_force_time Then
 If Modify_thermo_setting < 1980 Then
                 Modify_thermo_setting = Modify_thermo_setting + 16
 Call Modify_setting_lcd(modify_thermo_setting)
 Waitms Button_force_delay
 End If
 Else
 If Button_plus_state = 0 Then
                 Button_plus_state = 1
 #if Button_beep_state = 1
 Sound Sreaker , 80 , 400
                   Sreaker = 0
 #endif
 If Modify_thermo_setting < 2000 Then ' + 125C
                   Temp_shift = Modify_thermo_setting And 15
                   Temp_1 = Lookup(temp_shift , Button_modify_label)
                   Modify_thermo_setting = Modify_thermo_setting + Temp_1
 Call Modify_setting_lcd(modify_thermo_setting)
 End If
 End If
 End If

 Else
        Button_plus_state = 0
 End If

 Elseif Button_minus = 0 And Button_plus = 1 Then ' Button is pressed "- / settings".
 Waitms Button_delay
 If Button_minus = 0 Then
         Thermo_mode_save_counter = 0
 If Button_force_counter >= Button_force_time Then
 If Modify_thermo_setting > -860 Then
               Modify_thermo_setting = Modify_thermo_setting - 16
 Call Modify_setting_lcd(modify_thermo_setting)
 Waitms Button_force_delay
 End If
 Else
 If Button_minus_state = 0 Then
               Button_minus_state = 1
 #if Button_beep_state = 1
 Sound Sreaker , 80 , 400
                 Sreaker = 0
 #endif
 If Modify_thermo_setting > -880 Then ' - 55C
                 Temp_shift = Modify_thermo_setting And 15
                 Temp_1 = Lookup(temp_shift , Button_modify_label)
                 Modify_thermo_setting = Modify_thermo_setting - Temp_1
 Call Modify_setting_lcd(modify_thermo_setting)
 End If
 End If
 End If
 Else
        Button_minus_state = 0
 End If
 Else ' The buttons are not pressed or pressed just two.
    Button_plus_state = 0
    Button_minus_state = 0
    Button_force_counter = 0
 End If


 If Thermo_mode_save_counter >= Thermo_mode_save_time Then ' If the button is never pressed for a preset constant Thermo_mode_save_Time number of seconds, save the settings and exit to standart mode.
 If Modify_thermo_setting <> Thermo_setting Then ' If supported by the temperature change
       Ee_thermosetting = Modify_thermo_setting             ' save the settings in the EEPROM.
       Thermo_setting = Modify_thermo_setting
 End If
     Thermo_mode_save_counter = 0
     Thermo_mode = 0
     Thermo_mode_counter = 0
     Thermo_mode_state = 0
     Button_plus_state = 0
     Button_minus_state = 0
 End If

End Sub



' Subroutine LCD display data on the selection mode of the temperature.
Sub Modify_setting_lcd(thermo As Integer)
 Local Lcd_out As Single
 Lcd_out = Thermo / 16
 Cls
 Lcd Spc(4) ; "Setting"
 Lowerline
 Lcd "set t" ; Chr(1) ; ": " ; Fusing(lcd_out , "#.#") ; Chr(1) ; "C"
End Sub



' Data output on the display.
Sub Thermo_lcd(thermo As Integer)
 Local Lcd_out As Single
 Cls
  Lcd_out = Thermo / 16
 Lcd "Thermo: " ; Fusing(lcd_out , "#.#") ; Chr(1) ; "C"

 If Button_plus = 0 Then
 Waitms Button_delay
 If Button_plus = 0 Then
       Lcd_out = Thermo_setting / 16
 Lowerline
 Lcd "set t" ; Chr(1) ; ": " ; Fusing(lcd_out , "#.#") ; Chr(1) ; "C"
 #if Button_beep_state = 1
 If Button_plus_state = 0 Then
           Button_plus_state = 1
 Sound Sreaker , 80 , 400
           Sreaker = 0
 End If
 #endif
 Else
     Button_plus_state = 0
 End If
 Else
   Button_plus_state = 0
 End If

End Sub



' Temperature control for load management.
Sub Thermocontrol(thermo As Integer , Thermosetting As Integer)
 If Thermo <= Thermosetting Then
 #if Thermostat_type = 0
     Out_thermostat = 1
 #else
     Out_thermostat = 0
 #endif
 Else
 #if Thermostat_type = 0
     Out_thermostat = 0
 #else
     Out_thermostat = 1
 #endif
 End If
End Sub




' ***************************** Function ***************************************

' Reading data from a temperature sensor.
Function Read_thermo(thermo As Byte) As Byte
 Local Temp As Byte
 Temp = 0                                                   ' Set tag read errors.
 Disable Interrupts
   Led_read_1wire = 1
 1wreset ' Reset sensor.
 If Err = 0 Then
 1wwrite &HCC                                         ' Command "Skip ROM"
 1wwrite &HBE                                         ' Command "Read Scratchpad".
       Temp_1wirearray(1) = 1wread(9) ' ňĺčĺ äŕűő ń äŕňčęŕ.
 1wreset ' Reset sensor.
 1wwrite &HCC                                         ' Command "Skip ROM".
 1wwrite &H44                                         ' Command "Convert  T"
 If Temp_1wirearray(9) = Crc8(temp_1wirearray(1) , 8) Then ' Checksum.
 For Temp = 1 To 8
           Thermo(temp) = Temp_1wirearray(temp)
 Next Temp
         Temp = 1                                           ' Reset tag read errors.
         Led_read_1wire = 0
 End If
 End If
 Enable Interrupts
 Read_thermo = Temp
End Function

' ******************************* Data ***************************************

Button_modify_label:
Data 2 , 1 , 1 , 2 , 1 , 2 , 1 , 1 , 2 , 1 , 1 , 2 , 1 , 2 , 1 , 1