From c5f3e07f41ebc8fc81b30c1ce2b27ab853f178f1 Mon Sep 17 00:00:00 2001 From: Christian Pointner Date: Fri, 28 Jun 2013 02:50:41 +0000 Subject: improved i2c_init git-svn-id: https://svn.spreadspace.org/mur.sat@795 7de4ea59-55d0-425e-a1af-a3118ea81d4c --- software/ihu/i2c.inc | 12 ++++-------- software/ihu/ihu.asm | 3 ++- 2 files changed, 6 insertions(+), 9 deletions(-) (limited to 'software') diff --git a/software/ihu/i2c.inc b/software/ihu/i2c.inc index bbd424f..072d01d 100644 --- a/software/ihu/i2c.inc +++ b/software/ihu/i2c.inc @@ -30,15 +30,11 @@ ;; ------------------------------------- i2c_init - bsf STATUS,RP0 ; make them outputs first - bcf I2C_SDA ; every write access is read-update-write - bcf I2C_SCL ; therefore the second bcf SDA sets SCL again - bcf STATUS,RP0 ; because of the external pull-up - bcf I2C_SCL - bcf I2C_SDA + movlw I2C_MASK ; as every write access is read-update-write this needs + andwf I2C_PORT,f ; to be done in one step (external pull-ups!) bsf STATUS,RP0 - bsf I2C_SDA - bsf I2C_SCL + movlw ~I2C_MASK + iorwf I2C_PORT,f bcf STATUS,RP0 return diff --git a/software/ihu/ihu.asm b/software/ihu/ihu.asm index eef9547..33ca45d 100644 --- a/software/ihu/ihu.asm +++ b/software/ihu/ihu.asm @@ -71,7 +71,8 @@ #define I2C_SCL PORTD,0 #define I2C_SDA PORTD,1 I2C_PORT EQU PORTD -I2C_SDA_MASK EQU b'00000010' +I2C_MASK EQU b'00000011' +I2C_SDA_MASK EQU b'00000010' #define CTR_SS PORTD,2 #define BAT_SS PORTD,3 #define MPU_EN PORTD,4 -- cgit v1.2.3