@ -35,8 +35,6 @@ extern i2c_status_t tca9555_status;
/ / | 0 | 1 | 0 | 0 | A2 | A1 | A0 |
/ / | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
# define I2C_ADDR 0b0100000
# define I2C_ADDR_WRITE ((I2C_ADDR << 1) | I2C_WRITE)
# define I2C_ADDR_READ ((I2C_ADDR << 1) | I2C_READ)
/ / Register addresses
# define IODIRA 0x06 / / i / o direction register
@ -64,19 +62,14 @@ uint8_t init_tca9555(void) {
/ / - unused : input : 1
/ / - input : input : 1
/ / - driving : output : 0
tca9555_status = i2c_start ( I2C_ADDR_WRITE , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_write ( IODIRA , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
/ / This means : write on pin 5 of port 0 , read on rest
tca9555_status = i2c_write ( 0 b11011111 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
/ / This means : we will write on pins 0 to 2 on port 1. read rest
tca9555_status = i2c_write ( 0 b11111000 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
out :
i2c_stop ( ) ;
uint8_t conf [ 2 ] = {
/ / This means : write on pin 5 of port 0 , read on rest
0 b11011111 ,
/ / This means : we will write on pins 0 to 2 on port 1. read rest
0 b11111000 ,
} ;
tca9555_status = i2c_writeReg ( I2C_ADDR , IODIRA , conf , 2 , I2C_TIMEOUT ) ;
return tca9555_status ;
}
@ -192,36 +185,29 @@ static matrix_row_t read_cols(uint8_t row) {
if ( tca9555_status ) { / / if there was an error
return 0 ;
} else {
uint8_t data = 0 ;
uint8_t port0 = 0 ;
uint8_t port1 = 0 ;
tca9555_status = i2c_start ( I2C_ADDR_WRITE , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_write ( IREGP0 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_start ( I2C_ADDR_READ , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_read_ack ( I2C_TIMEOUT ) ;
if ( tca9555_status < 0 ) goto out ;
port0 = ( uint8_t ) tca9555_status ;
tca9555_status = i2c_read_nack ( I2C_TIMEOUT ) ;
if ( tca9555_status < 0 ) goto out ;
port1 = ( uint8_t ) tca9555_status ;
/ / The initial state was all ones and any depressed key at a given column for the currently selected row will have its bit flipped to zero .
/ / The return value is a row as represented in the generic matrix code were the rightmost bits represent the lower columns and zeroes represent non - depressed keys while ones represent depressed keys .
/ / Since the pins are not ordered sequentially , we have to build the correct dataset from the two ports . Refer to the schematic to see where every pin is connected .
data | = ( port0 & 0x01 ) ;
data | = ( port0 & 0x02 ) ;
data | = ( port1 & 0x10 ) > > 2 ;
data | = ( port1 & 0x08 ) ;
data | = ( port0 & 0x40 ) > > 2 ;
data = ~ ( data ) ;
tca9555_status = I2C_STATUS_SUCCESS ;
out :
i2c_stop ( ) ;
return data ;
uint8_t data = 0 ;
uint8_t ports [ 2 ] = { 0 } ;
tca9555_status = i2c_readReg ( I2C_ADDR , IREGP0 , ports , 2 , I2C_TIMEOUT ) ;
if ( tca9555_status ) { / / if there was an error
/ / do nothing
return 0 ;
} else {
uint8_t port0 = ports [ 0 ] ;
uint8_t port1 = ports [ 1 ] ;
/ / The initial state was all ones and any depressed key at a given column for the currently selected row will have its bit flipped to zero .
/ / The return value is a row as represented in the generic matrix code were the rightmost bits represent the lower columns and zeroes represent non - depressed keys while ones represent depressed keys .
/ / Since the pins are not ordered sequentially , we have to build the correct dataset from the two ports . Refer to the schematic to see where every pin is connected .
data | = ( port0 & 0x01 ) ;
data | = ( port0 & 0x02 ) ;
data | = ( port1 & 0x10 ) > > 2 ;
data | = ( port1 & 0x08 ) ;
data | = ( port0 & 0x40 ) > > 2 ;
data = ~ ( data ) ;
tca9555_status = I2C_STATUS_SUCCESS ;
return data ;
}
}
}
}
@ -263,18 +249,10 @@ static void select_row(uint8_t row) {
default : break ;
}
tca9555_status = i2c_start ( I2C_ADDR_WRITE , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_write ( OREGP0 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_write ( port0 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
tca9555_status = i2c_write ( port1 , I2C_TIMEOUT ) ;
if ( tca9555_status ) goto out ;
uint8_t ports [ 2 ] = { port0 , port1 } ;
tca9555_status = i2c_writeReg ( I2C_ADDR , OREGP0 , ports , 2 , I2C_TIMEOUT ) ;
/ / Select the desired row by writing a byte for the entire GPIOB bus where only the bit representing the row we want to select is a zero ( write instruction ) and every other bit is a one .
/ / Note that the row - MATRIX_ROWS_PER_SIDE reflects the fact that being on the right hand , the columns are numbered from MATRIX_ROWS_PER_SIDE to MATRIX_ROWS , but the pins we want to write to are indexed from zero up on the GPIOB bus .
out :
i2c_stop ( ) ;
}
}
}