;********************************************************************** ; * ; Filename: AFR_meter_main.asm * ; Date: 14 August 2010 * ; File Version: 1.0.0 * ; * ; Author: Dave Critchley * ; * ; * ;********************************************************************** ; * ; Files Required: P16F876a.INC * ; * ;********************************************************************** ; * ; Notes: * ; |--\/--| * ; ICSP VPP/MCLR -|1 28|- PGD ICSP * ; C1 IN- -|2 27|- PGC ICSP * ; C2 IN- -|3 26|- LCD R/W * ; C2 IN+ -|4 25|- LCD RS * ; C1 IN+ -|5 24|- LCD D7 * ; C1 OUT -|6 23|- LCD D6 * ; C2 OUT -|7 22|- LCD D5 * ; VSS -|8 21|- LCD D4 * ; XTAL -|9 20|- VDD * ; XTAL -|10 19|- VSS * ; LCD E -|11 18|- RX * ; PWM2 OUT -|12 17|- TX * ; PWM1 OUT -|13 16|- * ; -|14 15|- * ; -------- * ; Serial data from Innovate LC1 is input on RX * ; PWM1 (0-5V) outputs Lambda value 0v=7.35, 5v=22.xx * ; PWM2 (1-0V) outputs Lambda reverse of above for std gauge * ; * ; LCD (4 bit) shows warmup, error codes and lambda * ; * ; The 2 Comparators are used as buffer amps for the RC Filtered * ; pwm outputs * ; * ; XTAL = 4MHz Serial 19200 N 8 1 * ; * ;********************************************************************** ; ; ; Notes on operation ; ; ; ; LC1 packet frame is 6 bytes ; ; B2 82 13 ; ; ; is one of 43,47,4B,4F,53,57,5B,5F - indicating data format ; ; of lambda word ; ; ; ; is the high value of lambda word (x128) for lambda readings ; ; below 22 only bottom 2 bits are of interest ; ; ; ; is lower 7 bits of Lambda word - 8th bit is 0 and not relevant ; ; ; ; ; ; ; Function : ; ; ; Func2..0 ; ; 000 Lambda valid and Aux data valid, normal operation ;. ; 001 Lambda value contains O2 level in 1/10% ; ; 010 Free air Calib in progress, Lambda data not valid ; ; 011 Need Free air Calibration Request, Lambda data not valid ; ; 100 Warming up, Lambda value is temp in 1/10% of operating temp. ; ; 101 Heater Calibration, Lambda value contains calibration countdown. ; ; 110 Error code in Lambda value ; ; 111 reserved ; ; ; ; 3rd Byte Indicates the mode ; ; ; 43 - Lambda ; ; 47 - O2 level 1/10 % (L7 + L6-L0) 8 bit binary value (0x151=20.9%) ; ; 4B - Free air Calib ; ; 4F - Need Free Air Calib ; ; 53 - Warmup - Lambda value is warmup in 1/10% ; ; 57 - Heater Calibration - Lambda value is countdown ; ; 5B - Error Code - Lambda value (low 4 bits) error code as table below ; ; 5F - N/A Reserved ; ; ; Error Table (lower 4 bits of ; ; ; 0 00h No error, last error cleared ; ; 1 01h Heater circuit shorted ; ; 2 02h Heater circuit open ; ; 3 03h Pump cell circuit shorted or too low an impedance ; ; 4 04h Pump cell circuit open or too high an impedance ; ; 5 05h Nernst cell circuit shorted or too low an impedance ; ; 6 06h Nernst cell circuit open or too high an impedance ; ; 7 07h For future use ; ; 8 08h Sensor timed out, possible damaged sensor ; ; 9 09h Battery voltage too low ; ; ; ; ; ; ; ; ; ; Lambda sets PWM1 duty cycle (0V = 0% to 5V = 100% ) ; ; PWM2 = FF-PWM1 value (so inverted) ; ; ; ; ; ;********************************************************************** ; *** Set Tabs to 14 when viewing the source code listing for nice formatting of output *** list p=16f876a ; list directive to define processor include "P16F876a.inc" ; processor specific variable definitions __CONFIG _CP_OFF & _CPD_OFF & _BODEN_ON & _PWRTE_ON & _WDT_OFF & _XT_OSC & _LVP_OFF & _DEBUG_OFF errorlevel -302 ; suppress banksel warning messages ; '__CONFIG' directive is used to embed configuration data within .asm file. ; The labels following the directive are located in the respective .inc file. ; See respective data sheet for additional information on configuration word. ; Load code release data in to EEPROM org 0x2108 de " http://homoautomatus.co.uk " de " Dave Critchley (c) 2010 " de " AFR Meter for Innovate serial > PWM 1.0.0 " ;***** VARIABLE DEFINITIONS cblock 0x20 SerFN ; Store Function Byte SerLH ; Lambda High Word SerLL ; Lambda Low Word Flags ; byte to store indicator flags LO_TEMP ; holds 8 bit binary for BCD Conversion TEMP1 ; counter for BCD converter TEMP2 ; working reg for BCD conversion temp ; temp storage ltmp ; lcd nibble holder cntmsec ; delay timer duty1 duty2 ldcnt endc ;**************************************************************************** ; Defines and equates ;**************************************************************************** ;Macros to select the register bank ;Many bank changes can be optimized when only one STATUS bit changes Bank0 MACRO ;macro to select data RAM bank 0 bcf STATUS,RP0 bcf STATUS,RP1 ENDM Bank1 MACRO ;macro to select data RAM bank 1 bsf STATUS,RP0 bcf STATUS,RP1 ENDM Bank2 MACRO ;macro to select data RAM bank 2 bcf STATUS,RP0 bsf STATUS,RP1 ENDM Bank3 MACRO ;macro to select data RAM bank 3 bsf STATUS,RP0 bsf STATUS,RP1 ENDM EStrobe MACRO ; Strobe the "E" Bit bsf LCD_E nop bcf LCD_E ENDM ;Constants ; base frequency XTAL_FREQ EQU .4000000 ; OSC freq in Hz ; BAUD_19200 EQU (((10*XTAL_FREQ/(16*19200))+5)/10)-1 BAUD_19200 EQU (XTAL_FREQ/(.16*.19200))-1 ;---------------------------------------------------------------------------- ;Bit Definitions #define BCflag Flags,0x00 ; blank checker for preceeding zeros #define RXflag Flags,0x01 ; Received Char Flag #define HiFlag Flags,0x02 ; Flag for High order bits of Lambda word ; #define LCD_RW PORTB,5 ; Bit 5 on PORTB #define LCD_RS PORTB,4 ; Bit 4 on PORTB #define LCD_E PORTC,0 ; Bit 0 on PORTC #define LED PORTC,4 ; Bit 4 on PORTC ;LCD_RW equ 5 ; Bit 5 on PORTB ;LCD_RS equ 4 ; Bit 4 on PORTB ;LCD_E equ 0 ; Bit 0 on PORTC ; string equates CALIB = lCALIB-shomsg _IN = l_IN-shomsg PROGRESS = lPROGRESS-shomsg REQUIRED = lREQUIRED-shomsg WARMUP = lWARMUP-shomsg HEATER = lHEATER-shomsg BLANK = lBLANK-shomsg BLANK3 = lBLANK3-shomsg LEAN = lLEAN-shomsg RICH = lRICH-shomsg AFR = lAFR-shomsg ERRMSG = lERROR-shomsg _O2 = l_O2-shomsg HELLO = l_HELLO-shomsg AUTHOR = l_AUTHOR-shomsg ;********************************************************************** ORG 0x000 ; processor reset vector include "AFR_meter_code.asm" ORG 0x0020 ; Strings start at address 20 shomsg: addwf PCL,f ; index into strings lCALIB: dt "CALIB",0x00 l_IN: dt " IN",0x00 lPROGRESS: dt "PROGRESS",0x00 lREQUIRED: dt "REQUIRED",0x00 lWARMUP: dt "WARMUP ",0x00 lHEATER: dt "HEATER ",0x00 lBLANK: dt " ",0x00 lBLANK3 dt " ",0x00 lLEAN: dt "LEAN",0x00 lRICH: dt "RICH",0x00 lAFR: dt "AFR ",0x00 lERROR: dt "ERROR ",0x00 l_O2: dt "O2% ",0x00 l_HELLO: dt "AFR V1.0",0x00 l_AUTHOR: dt "DCX 2010",0x00 ORG 0x0100 ; AFR Table at address 100 getlambda: addwf PCL,f ; table contains AFR readings (7.3 to 22.3) include "LCD_AFR_Value_Table.inc" END ; directive 'end of program'