first working I2C code

git-svn-id: https://svn.spreadspace.org/mur.sat@68 7de4ea59-55d0-425e-a1af-a3118ea81d4c

1 files changed, 161 insertions, 22 deletions

diff --git a/software/ihu/ihu.asm b/software/ihu/ihu.asm
index d9bdc69..88fc5c0 100644
--- a/software/ihu/ihu.asm
+++ b/software/ihu/ihu.asm
@@ -38,8 +38,37 @@
   ;; -------------------------------------
   ;; DEFINES
   ;;   constants
+RTC_ADDR_W   EQU b'11010000'
+RTC_ADDR_R   EQU b'11010001'
+I2C_SPEED    EQU .19
   
-  ;;   I/O Pins
+  ;; I/O Pins
+;; PortA
+SOLAR_C0     EQU 0
+SOLAR_C1     EQU 1
+SOLAR_C2     EQU 2
+SOLAR_C3     EQU 3
+OWIRE        EQU 4
+SOLAR_C4     EQU 5
+;; PortB
+DTMF_INT     EQU 0
+BAT_V        EQU 1
+SOLAR_V      EQU 2
+BAT_C        EQU 3
+MPU_PWRDWN   EQU 4
+MPU_RESET    EQU 5
+MPU_INT      EQU 6
+RTC_INT      EQU 7
+;; PortC
+MPU_CLK      EQU 0
+MPU_SDO      EQU 1
+MPU_SDI      EQU 2
+RTC_SCL      EQU 3
+RTC_SDA      EQU 4
+MPU_CS       EQU 5
+ICOM_TX      EQU 6
+ICOM_RX      EQU 7
+;; PortD
 DTMF_D0      EQU 0
 DTMF_D1      EQU 1
 DTMF_D2      EQU 2
@@ -48,6 +77,10 @@ DTMF_PWRDWN  EQU 4
 TTX_RESET    EQU 5
 TTX_SCL      EQU 6
 TTX_SDA      EQU 7
+;; PortE
+SOLAR_C5     EQU 0
+SOLAR_C6     EQU 1
+SOLAR_C7     EQU 2
   
   ;;   variables
   ;;     page 0 only
@@ -116,15 +149,25 @@ init
   bsf       STATUS,RP1
   movlw     b'00000000'
   movwf     BAUDCTL
-
+  movlw     b'00000111'
+  movwf     ANSELH
+  
   ;; bank 1
   bsf       STATUS,RP0
   bcf       STATUS,RP1
   movlw     b'11000001'
+  movwf     WPUB
+  movlw     b'11000000'
+  movwf     IOCB
+  movlw     b'01000001'
   movwf     OPTION_REG
   clrf      PSTRCON
   movlw     b'00010000'
   movwf     OSCCON
+  movlw     b'11001111'
+  movwf     TRISB
+  movlw     b'11011100'
+  movwf     TRISC
   movlw     b'10001111'
   movwf     TRISD
   movlw     b'00100100'
@@ -132,6 +175,9 @@ init
   movlw     .12
   movwf     SPBRG
   clrf      SPBRGH
+  movlw     I2C_SPEED
+  movwf     SSPADD
+  bsf       SSPSTAT,SMP
   movlw     b'00100000'
   movwf     PIE1
   clrf      PIE2
@@ -141,6 +187,8 @@ init
   bcf       STATUS,RP1
   movlw     b'10010000'
   movwf     RCSTA
+  movlw     b'00101000'
+  movwf     SSPCON
   movlw     B'01000000'
   movwf     INTCON
   
@@ -294,7 +342,116 @@ ttx_csum_error
   movlw     'E'
   movwf     TXREG
   return
+
+  ;; -------------------------------------
+i2c_start
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bsf       SSPCON2,SEN
+  bcf       STATUS,RP0
+  goto      i2c_wait
+  
+  ;; ------------------
+i2c_restart
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bsf       SSPCON2,RSEN
+  bcf       STATUS,RP0
+  goto      i2c_wait
   
+  ;; ------------------
+i2c_stop
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bsf       SSPCON2,PEN
+  bcf       STATUS,RP0
+  goto      i2c_wait
+  
+  ;; ------------------
+i2c_send_byte
+  bcf       PIR1,SSPIF
+  movwf     SSPBUF
+  goto      i2c_wait
+
+  ;; ------------------
+i2c_recv_byte
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bsf       SSPCON2,RCEN
+  bcf       STATUS,RP0
+  goto      i2c_wait
+
+  ;; ------------------
+i2c_ack
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bcf       SSPCON2,ACKDT
+  bsf       SSPCON2,ACKEN
+  bcf       STATUS,RP0
+  goto      i2c_wait
+  
+  ;; ------------------
+i2c_nack
+  bcf       PIR1,SSPIF
+  bsf       STATUS,RP0
+  bsf       SSPCON2,ACKDT
+  bsf       SSPCON2,ACKEN
+  bcf       STATUS,RP0
+
+i2c_wait
+  btfss     PIR1,SSPIF
+  goto      i2c_wait
+  return
+
+  ;; -------------------------------------
+rtc_init
+  call      i2c_start
+  
+  movlw     RTC_ADDR_W
+  call      i2c_send_byte
+  bsf       STATUS,RP0
+  btfsc     SSPCON2,ACKSTAT
+  goto      rtc_init_error_ack
+  bcf       STATUS,RP0
+  
+  movlw     H'0E'
+  call      i2c_send_byte
+  bsf       STATUS,RP0
+  btfsc     SSPCON2,ACKSTAT
+  goto      rtc_init_error_ack
+  bcf       STATUS,RP0
+
+  call      i2c_restart
+  
+  movlw     RTC_ADDR_R
+  call      i2c_send_byte
+  bsf       STATUS,RP0
+  btfsc     SSPCON2,ACKSTAT
+  goto      rtc_init_error_ack
+  bcf       STATUS,RP0
+
+  call      i2c_recv_byte
+  movf      SSPBUF,w
+  movwf     TXREG
+  call      i2c_ack
+
+  call      i2c_recv_byte
+  movf      SSPBUF,w
+  movwf     TXREG
+  call      i2c_nack
+
+  call      i2c_stop
+  movlw     '.'
+  movwf     TXREG
+  return
+  
+rtc_init_error_ack
+  bcf       STATUS,RP0
+  call      i2c_stop
+  movlw     'E'
+  movwf     TXREG
+  return
+
   ;; -------------------------------------
   ;; MAINLOOP
 main
@@ -302,26 +459,8 @@ main
   btfsc     STATUS,Z
   goto      main
 
-  movlw     'M'
-  movwf     BUF
-  movlw     'U'
-  movwf     BUF + 1
-  movlw     'R'
-  movwf     BUF + 2
-  movlw     '.'
-  movwf     BUF + 3
-  movlw     'S'
-  movwf     BUF + 4
-  movlw     'A'
-  movwf     BUF + 5
-  movlw     'T'
-  movwf     BUF + 6
-  
-  movlw     BUF
-  movwf     FSR
-  movlw     b'11110111'
-  call      ttx_send_frame
-
+  call      rtc_init
+    
   clrf      TMP
   goto      main