Folosirea RTCC hardware din PIC

[Mircea]

Cum voiam sa incorporez un ceas intr-un proiect, am avut de ales intre partea clasica pe internet DS1307, 3231 (pe I2C) sau MCP795x0 (pe SPI), etc., sau sa lucrez cu RTCC-ul inclus in cateva familii PIC 16F191xx, 18FJ si 18FK.

 

Cel mai mic PIC (care va putea adresa si un LCD/GLCD/TFT - depinde de model) cu RTCC este 16F19155 (14 pini). Toate sub 2$ bucata la producator dar intre 2-3$ la vanzare (TME.eu).

 

NB: al doilea C din RTCC vine de la calendar.

 

Eu l-am incercat pe un 18F46J50 la care aveam deja un montaj facut. Am folosit oscilatorul intern RC cu PLL, astfel ca PIC-ul rula la 48MHz. Performantele au fost mediocre, dar intrucat pinii T1OSO si T1OSI (la 18FJ sau SOSCO/SOSCI la 18FK) erau ocupati n-am putut sa pun un quartz de 32,768kHz. Evident ca un quartz este obligatioriu si va face o mare diferenta in performante.

 

PIC-ul este conectat la un TFT, codul de mai jos nu face initializarea lui, etc. N-am stat sa curat mai mult codul prezentat. Nu sugerez TFT-ul caci refresh-ul se face aiurea (daca folosesti bibliotecile Mikroe) fata de un LCD sau GLCD.

 

Capturi de cod pentru Mikrobasic, dar cu putin efort pot pune si in Mikroc.

 

Variable folosite:

' Declarations section
dim year, day, month, wekday, hours, seconds, minutes            as word
    txt                                                          as string[4] 

Initializare RTCC:

' RTCC Init
sub procedure Init_RTCC()
  asm
    movlb 0x0F
    bcf INTCON, GIE
    movlw 0x55
    movwf EECON2
    movlw 0xAA
    movwf EECON2
    bsf RTCCFG,RTCWREN
  end asm

  PADCFG1.RTSECSEL1 = 1
  PADCFG1.RTSECSEL0 = 0

  RTCCFG     = 0x23 ' set pointer to Year
  RTCVALL    = 0x18 ' set Year to 2018
  RTCCFG     = 0x22 ' set pointer to Month & Day
  RTCVALL    = 0x20 ' set Day to the 20th
  RTCVALH    = 0x12 ' set Month to Jan (decrements pointer to Weekday & Hours)
  RTCVALL    = 0x13 ' set Hour to 13
  RTCVALH    = 0x06 ' 0=Sun, 6=Sat. set Weekday (decrements pointer to Minutes & Seconds)
  RTCVALL    = 0x00 ' set Seconds to 00
  RTCVALH    = 0x15 ' set Minutes to 00
  RTCCFG.RTCEN   = 1 ' RTCC enabled
  Delay_ms(800) '

  asm
    movlb 0x0F
    bcf INTCON, GIE
    movlw 0x55
    movwf EECON2
    movlw 0xAA
    movwf EECON2
    bcf RTCCFG,RTCWREN
  end asm

end sub

In procedura de initializare a PIC-ului (felul meu de a lucra) se va apela aceasta Init_RTCC().

 

In bucla principala se introduce:

' RTCC TFT update
   RTCCFG  = 3                                ' set pointer to Year
   year    = RTCVALL                          ' read Year
   RTCCFG  = 2                                ' set pointer to Month & Day
   day     = RTCVALL                          ' read Day
   month   = RTCVALH                          ' read Month & decrement pointer
   RTCCFG  = 1                                ' set pointer to Month & Day
   hours   = RTCVALL                          ' read Hours
   wekday  = RTCVALH                          ' read Weekday & decrement pointer
   RTCCFG  = 0                                ' set pointer to Month & Day
   seconds = RTCVALL                          ' read Seconds
   minutes = RTCVALH                          ' read Minutes (pointer already at 0)

   hours    = (((hours   and 0x30) >> 4) * 10) + (hours   and 0x0F)
   minutes  = (((minutes and 0x70) >> 4) * 10) + (minutes and 0x0F)
   seconds  = (((seconds and 0x70) >> 4) * 10) + (seconds and 0x0F)
   year     = (((year    and 0xF0) >> 4) * 10) + (year    and 0x0F)
   month    = (((month   and 0x10) >> 4) * 10) + (month   and 0x0F)
   day      = (((day     and 0x30) >> 4) * 10) + (day     and 0x0F)

' Time
   TFT_Set_Pen(CL_GRAY, 1)
   TFT_Set_Brush(1, 0, 1, LEFT_TO_RIGHT, CL_GRAY, CL_GRAY)
   TFT_Rectangle(230, 5, 310, 60)
   TFT_Set_Font(@TFT_defaultFont, CL_AQUA, FO_HORIZONTAL)
   ByteToStr(hours, txt)
   TFT_Write_Text(txt, 232, 13)
   TFT_Write_Text(":", 251, 13)
   ByteToStr(minutes, txt)
   TFT_Write_Text(txt, 256, 13)
   TFT_Write_Text(":", 275, 13)
   ByteToStr(seconds, txt)
   TFT_Write_Text(txt, 280, 13)
' Date
   TFT_Write_Text("20", 232, 30)
   ByteToStr(year, txt)
   TFT_Write_Text(txt, 245, 30)
   TFT_Write_Text("/", 264, 30)
   ByteToStr(month, txt)
   TFT_Write_Text(txt, 269, 30)
   TFT_Write_Text("/", 287, 30)
   ByteToStr(day, txt)
   TFT_Write_Text(txt, 293, 30)