diff options
| author | QMK Bot <hello@qmk.fm> | 2021-09-07 15:35:32 +0000 |
|---|---|---|
| committer | QMK Bot <hello@qmk.fm> | 2021-09-07 15:35:32 +0000 |
| commit | af19461a02b8a5f89d26c448b10984aa0ac19f42 (patch) | |
| tree | be484d88bf4d4621355c4fd5f8d30bbd4117e1d1 /keyboards/sx60 | |
| parent | c669c4376972446f52340584976d935ea9bf23ca (diff) | |
| parent | 04c0704b280c4847c43b164335e9741b19219131 (diff) | |
| download | qmk_firmware-af19461a02b8a5f89d26c448b10984aa0ac19f42.tar.gz qmk_firmware-af19461a02b8a5f89d26c448b10984aa0ac19f42.zip | |
Merge remote-tracking branch 'origin/master' into develop
Diffstat (limited to 'keyboards/sx60')
| -rw-r--r-- | keyboards/sx60/i2cmaster.h | 178 | ||||
| -rw-r--r-- | keyboards/sx60/matrix.c | 21 | ||||
| -rwxr-xr-x | keyboards/sx60/rules.mk | 4 | ||||
| -rwxr-xr-x | keyboards/sx60/sx60.c | 31 | ||||
| -rwxr-xr-x | keyboards/sx60/sx60.h | 5 | ||||
| -rw-r--r-- | keyboards/sx60/twimaster.c | 207 |
6 files changed, 25 insertions, 421 deletions
diff --git a/keyboards/sx60/i2cmaster.h b/keyboards/sx60/i2cmaster.h deleted file mode 100644 index 3917b9e6c..000000000 --- a/keyboards/sx60/i2cmaster.h +++ /dev/null | |||
| @@ -1,178 +0,0 @@ | |||
| 1 | #ifndef _I2CMASTER_H | ||
| 2 | #define _I2CMASTER_H 1 | ||
| 3 | /************************************************************************* | ||
| 4 | * Title: C include file for the I2C master interface | ||
| 5 | * (i2cmaster.S or twimaster.c) | ||
| 6 | * Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury | ||
| 7 | * File: $Id: i2cmaster.h,v 1.10 2005/03/06 22:39:57 Peter Exp $ | ||
| 8 | * Software: AVR-GCC 3.4.3 / avr-libc 1.2.3 | ||
| 9 | * Target: any AVR device | ||
| 10 | * Usage: see Doxygen manual | ||
| 11 | **************************************************************************/ | ||
| 12 | |||
| 13 | #ifdef DOXYGEN | ||
| 14 | /** | ||
| 15 | @defgroup pfleury_ic2master I2C Master library | ||
| 16 | @code #include <i2cmaster.h> @endcode | ||
| 17 | |||
| 18 | @brief I2C (TWI) Master Software Library | ||
| 19 | |||
| 20 | Basic routines for communicating with I2C slave devices. This single master | ||
| 21 | implementation is limited to one bus master on the I2C bus. | ||
| 22 | |||
| 23 | This I2c library is implemented as a compact assembler software implementation of the I2C protocol | ||
| 24 | which runs on any AVR (i2cmaster.S) and as a TWI hardware interface for all AVR with built-in TWI hardware (twimaster.c). | ||
| 25 | Since the API for these two implementations is exactly the same, an application can be linked either against the | ||
| 26 | software I2C implementation or the hardware I2C implementation. | ||
| 27 | |||
| 28 | Use 4.7k pull-up resistor on the SDA and SCL pin. | ||
| 29 | |||
| 30 | Adapt the SCL and SDA port and pin definitions and eventually the delay routine in the module | ||
| 31 | i2cmaster.S to your target when using the software I2C implementation ! | ||
| 32 | |||
| 33 | Adjust the CPU clock frequence F_CPU in twimaster.c or in the Makfile when using the TWI hardware implementaion. | ||
| 34 | |||
| 35 | @note | ||
| 36 | The module i2cmaster.S is based on the Atmel Application Note AVR300, corrected and adapted | ||
| 37 | to GNU assembler and AVR-GCC C call interface. | ||
| 38 | Replaced the incorrect quarter period delays found in AVR300 with | ||
| 39 | half period delays. | ||
| 40 | |||
| 41 | @author Peter Fleury pfleury@gmx.ch http://jump.to/fleury | ||
| 42 | |||
| 43 | @par API Usage Example | ||
| 44 | The following code shows typical usage of this library, see example test_i2cmaster.c | ||
| 45 | |||
| 46 | @code | ||
| 47 | |||
| 48 | #include <i2cmaster.h> | ||
| 49 | |||
| 50 | |||
| 51 | #define Dev24C02 0xA2 // device address of EEPROM 24C02, see datasheet | ||
| 52 | |||
| 53 | int main(void) | ||
| 54 | { | ||
| 55 | unsigned char ret; | ||
| 56 | |||
| 57 | i2c_init(); // initialize I2C library | ||
| 58 | |||
| 59 | // write 0x75 to EEPROM address 5 (Byte Write) | ||
| 60 | i2c_start_wait(Dev24C02+I2C_WRITE); // set device address and write mode | ||
| 61 | i2c_write(0x05); // write address = 5 | ||
| 62 | i2c_write(0x75); // write value 0x75 to EEPROM | ||
| 63 | i2c_stop(); // set stop conditon = release bus | ||
| 64 | |||
| 65 | |||
| 66 | // read previously written value back from EEPROM address 5 | ||
| 67 | i2c_start_wait(Dev24C02+I2C_WRITE); // set device address and write mode | ||
| 68 | |||
| 69 | i2c_write(0x05); // write address = 5 | ||
| 70 | i2c_rep_start(Dev24C02+I2C_READ); // set device address and read mode | ||
| 71 | |||
| 72 | ret = i2c_readNak(); // read one byte from EEPROM | ||
| 73 | i2c_stop(); | ||
| 74 | |||
| 75 | for(;;); | ||
| 76 | } | ||
| 77 | @endcode | ||
| 78 | |||
| 79 | */ | ||
| 80 | #endif /* DOXYGEN */ | ||
| 81 | |||
| 82 | /**@{*/ | ||
| 83 | |||
| 84 | #if (__GNUC__ * 100 + __GNUC_MINOR__) < 304 | ||
| 85 | #error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !" | ||
| 86 | #endif | ||
| 87 | |||
| 88 | #include <avr/io.h> | ||
| 89 | |||
| 90 | /** defines the data direction (reading from I2C device) in i2c_start(),i2c_rep_start() */ | ||
| 91 | #define I2C_READ 1 | ||
| 92 | |||
| 93 | /** defines the data direction (writing to I2C device) in i2c_start(),i2c_rep_start() */ | ||
| 94 | #define I2C_WRITE 0 | ||
| 95 | |||
| 96 | |||
| 97 | /** | ||
| 98 | @brief initialize the I2C master interace. Need to be called only once | ||
| 99 | @param void | ||
| 100 | @return none | ||
| 101 | */ | ||
| 102 | extern void i2c_init(void); | ||
| 103 | |||
| 104 | |||
| 105 | /** | ||
| 106 | @brief Terminates the data transfer and releases the I2C bus | ||
| 107 | @param void | ||
| 108 | @return none | ||
| 109 | */ | ||
| 110 | extern void i2c_stop(void); | ||
| 111 | |||
| 112 | |||
| 113 | /** | ||
| 114 | @brief Issues a start condition and sends address and transfer direction | ||
| 115 | |||
| 116 | @param addr address and transfer direction of I2C device | ||
| 117 | @retval 0 device accessible | ||
| 118 | @retval 1 failed to access device | ||
| 119 | */ | ||
| 120 | extern unsigned char i2c_start(unsigned char addr); | ||
| 121 | |||
| 122 | |||
| 123 | /** | ||
| 124 | @brief Issues a repeated start condition and sends address and transfer direction | ||
| 125 | |||
| 126 | @param addr address and transfer direction of I2C device | ||
| 127 | @retval 0 device accessible | ||
| 128 | @retval 1 failed to access device | ||
| 129 | */ | ||
| 130 | extern unsigned char i2c_rep_start(unsigned char addr); | ||
| 131 | |||
| 132 | |||
| 133 | /** | ||
| 134 | @brief Issues a start condition and sends address and transfer direction | ||
| 135 | |||
| 136 | If device is busy, use ack polling to wait until device ready | ||
| 137 | @param addr address and transfer direction of I2C device | ||
| 138 | @return none | ||
| 139 | */ | ||
| 140 | extern void i2c_start_wait(unsigned char addr); | ||
| 141 | |||
| 142 | |||
| 143 | /** | ||
| 144 | @brief Send one byte to I2C device | ||
| 145 | @param data byte to be transfered | ||
| 146 | @retval 0 write successful | ||
| 147 | @retval 1 write failed | ||
| 148 | */ | ||
| 149 | extern unsigned char i2c_write(unsigned char data); | ||
| 150 | |||
| 151 | |||
| 152 | /** | ||
| 153 | @brief read one byte from the I2C device, request more data from device | ||
| 154 | @return byte read from I2C device | ||
| 155 | */ | ||
| 156 | extern unsigned char i2c_readAck(void); | ||
| 157 | |||
| 158 | /** | ||
| 159 | @brief read one byte from the I2C device, read is followed by a stop condition | ||
| 160 | @return byte read from I2C device | ||
| 161 | */ | ||
| 162 | extern unsigned char i2c_readNak(void); | ||
| 163 | |||
| 164 | /** | ||
| 165 | @brief read one byte from the I2C device | ||
| 166 | |||
| 167 | Implemented as a macro, which calls either i2c_readAck or i2c_readNak | ||
| 168 | |||
| 169 | @param ack 1 send ack, request more data from device<br> | ||
| 170 | 0 send nak, read is followed by a stop condition | ||
| 171 | @return byte read from I2C device | ||
| 172 | */ | ||
| 173 | extern unsigned char i2c_read(unsigned char ack); | ||
| 174 | #define i2c_read(ack) (ack) ? i2c_readAck() : i2c_readNak(); | ||
| 175 | |||
| 176 | |||
| 177 | /**@}*/ | ||
| 178 | #endif | ||
diff --git a/keyboards/sx60/matrix.c b/keyboards/sx60/matrix.c index 6fa0dd145..b7dc25425 100644 --- a/keyboards/sx60/matrix.c +++ b/keyboards/sx60/matrix.c | |||
| @@ -243,15 +243,11 @@ static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) | |||
| 243 | /* if there was an error */ | 243 | /* if there was an error */ |
| 244 | return 0; | 244 | return 0; |
| 245 | } else { | 245 | } else { |
| 246 | uint16_t data = 0; | 246 | uint8_t data = 0; |
| 247 | mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out; | 247 | mcp23018_status = i2c_readReg(I2C_ADDR, GPIOA, &data, 1, I2C_TIMEOUT); |
| 248 | mcp23018_status = i2c_write(GPIOA); if (mcp23018_status) goto out; | 248 | if (!mcp23018_status) { |
| 249 | mcp23018_status = i2c_start(I2C_ADDR_READ); if (mcp23018_status) goto out; | 249 | current_matrix[current_row] |= (~((uint16_t)data) << 8); |
| 250 | data = i2c_readNak(); | 250 | } |
| 251 | data = ~data; | ||
| 252 | out: | ||
| 253 | i2c_stop(); | ||
| 254 | current_matrix[current_row] |= (data << 8); | ||
| 255 | } | 251 | } |
| 256 | 252 | ||
| 257 | /* For each col... */ | 253 | /* For each col... */ |
| @@ -278,11 +274,8 @@ static void select_row(uint8_t row) | |||
| 278 | /* set active row low : 0 | 274 | /* set active row low : 0 |
| 279 | set active row output : 1 | 275 | set active row output : 1 |
| 280 | set other rows hi-Z : 1 */ | 276 | set other rows hi-Z : 1 */ |
| 281 | mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out; | 277 | uint8_t port = 0xFF & ~(1<<abs(row-4)); |
| 282 | mcp23018_status = i2c_write(GPIOB); if (mcp23018_status) goto out; | 278 | mcp23018_status = i2c_writeReg(I2C_ADDR, GPIOB, &port, 1, I2C_TIMEOUT); |
| 283 | mcp23018_status = i2c_write(0xFF & ~(1<<abs(row-4))); if (mcp23018_status) goto out; | ||
| 284 | out: | ||
| 285 | i2c_stop(); | ||
| 286 | } | 279 | } |
| 287 | 280 | ||
| 288 | uint8_t pin = row_pins[row]; | 281 | uint8_t pin = row_pins[row]; |
diff --git a/keyboards/sx60/rules.mk b/keyboards/sx60/rules.mk index 8c2ad5259..1550b65c1 100755 --- a/keyboards/sx60/rules.mk +++ b/keyboards/sx60/rules.mk | |||
| @@ -27,5 +27,5 @@ RGBLIGHT_ENABLE = no | |||
| 27 | CUSTOM_MATRIX = yes | 27 | CUSTOM_MATRIX = yes |
| 28 | 28 | ||
| 29 | # project specific files | 29 | # project specific files |
| 30 | SRC = twimaster.c \ | 30 | QUANTUM_LIB_SRC += i2c_master.c |
| 31 | matrix.c | 31 | SRC += matrix.c |
diff --git a/keyboards/sx60/sx60.c b/keyboards/sx60/sx60.c index ede8c07e9..cb7f2b88f 100755 --- a/keyboards/sx60/sx60.c +++ b/keyboards/sx60/sx60.c | |||
| @@ -1,5 +1,5 @@ | |||
| 1 | #include "sx60.h" | 1 | #include "sx60.h" |
| 2 | #include "i2cmaster.h" | 2 | #include "i2c_master.h" |
| 3 | 3 | ||
| 4 | 4 | ||
| 5 | bool i2c_initialized = 0; | 5 | bool i2c_initialized = 0; |
| @@ -18,21 +18,18 @@ uint8_t init_mcp23018(void) { | |||
| 18 | 18 | ||
| 19 | /* B Pins are Row, A pins are Columns | 19 | /* B Pins are Row, A pins are Columns |
| 20 | Set them to output */ | 20 | Set them to output */ |
| 21 | mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out; | 21 | static uint8_t direction[2] = { |
| 22 | mcp23018_status = i2c_write(IODIRA); if (mcp23018_status) goto out; | 22 | 0b11111111, |
| 23 | mcp23018_status = i2c_write(0b11111111); if (mcp23018_status) goto out; | 23 | 0b00000000, |
| 24 | /* Now write to IODIRB */ | 24 | }; |
| 25 | mcp23018_status = i2c_write(0b00000000); if (mcp23018_status) goto out; | 25 | static uint8_t pullup[2] = { |
| 26 | i2c_stop(); | 26 | 0b11111111, |
| 27 | 27 | 0b00000000, | |
| 28 | mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out; | 28 | }; |
| 29 | mcp23018_status = i2c_write(GPPUA); if (mcp23018_status) goto out; | 29 | |
| 30 | mcp23018_status = i2c_write(0b11111111); if (mcp23018_status) goto out; | 30 | mcp23018_status = i2c_writeReg(I2C_ADDR, IODIRA, direction, 2, I2C_TIMEOUT); |
| 31 | /* Now write to GPPUB */ | 31 | if (mcp23018_status) return mcp23018_status; |
| 32 | mcp23018_status = i2c_write(0b00000000); if (mcp23018_status) goto out; | 32 | |
| 33 | 33 | mcp23018_status = i2c_writeReg(I2C_ADDR, GPPUA, pullup, 2, I2C_TIMEOUT); | |
| 34 | out: | ||
| 35 | i2c_stop(); | ||
| 36 | |||
| 37 | return mcp23018_status; | 34 | return mcp23018_status; |
| 38 | } | 35 | } |
diff --git a/keyboards/sx60/sx60.h b/keyboards/sx60/sx60.h index b9575c118..2c0aa8240 100755 --- a/keyboards/sx60/sx60.h +++ b/keyboards/sx60/sx60.h | |||
| @@ -3,13 +3,12 @@ | |||
| 3 | #include "quantum.h" | 3 | #include "quantum.h" |
| 4 | #include <stdint.h> | 4 | #include <stdint.h> |
| 5 | #include <stdbool.h> | 5 | #include <stdbool.h> |
| 6 | #include "i2cmaster.h" | 6 | #include "i2c_master.h" |
| 7 | #include <util/delay.h> | 7 | #include <util/delay.h> |
| 8 | 8 | ||
| 9 | /* I2C aliases and register addresses (see "mcp23018.md") */ | 9 | /* I2C aliases and register addresses (see "mcp23018.md") */ |
| 10 | #define I2C_ADDR 0b0100000 | 10 | #define I2C_ADDR 0b0100000 |
| 11 | #define I2C_ADDR_WRITE ( (I2C_ADDR<<1) | I2C_WRITE ) | 11 | #define I2C_TIMEOUT 100 |
| 12 | #define I2C_ADDR_READ ( (I2C_ADDR<<1) | I2C_READ ) | ||
| 13 | #define IODIRA 0x00 /* i/o direction register */ | 12 | #define IODIRA 0x00 /* i/o direction register */ |
| 14 | #define IODIRB 0x01 | 13 | #define IODIRB 0x01 |
| 15 | #define GPPUA 0x0C /* GPIO pull-up resistor register */ | 14 | #define GPPUA 0x0C /* GPIO pull-up resistor register */ |
diff --git a/keyboards/sx60/twimaster.c b/keyboards/sx60/twimaster.c deleted file mode 100644 index 30d8c24bf..000000000 --- a/keyboards/sx60/twimaster.c +++ /dev/null | |||
| @@ -1,207 +0,0 @@ | |||
| 1 | /************************************************************************* | ||
| 2 | * Title: I2C master library using hardware TWI interface | ||
| 3 | * Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury | ||
| 4 | * File: $Id: twimaster.c,v 1.3 2005/07/02 11:14:21 Peter Exp $ | ||
| 5 | * Software: AVR-GCC 3.4.3 / avr-libc 1.2.3 | ||
| 6 | * Target: any AVR device with hardware TWI | ||
| 7 | * Usage: API compatible with I2C Software Library i2cmaster.h | ||
| 8 | **************************************************************************/ | ||
| 9 | #include <inttypes.h> | ||
| 10 | #include <compat/twi.h> | ||
| 11 | |||
| 12 | #include <i2cmaster.h> | ||
| 13 | |||
| 14 | /* define CPU frequency in Hz here if not defined in Makefile */ | ||
| 15 | #ifndef F_CPU | ||
| 16 | #define F_CPU 16000000UL | ||
| 17 | #endif | ||
| 18 | |||
| 19 | /* I2C clock in Hz */ | ||
| 20 | #define SCL_CLOCK 400000L | ||
| 21 | |||
| 22 | |||
| 23 | /************************************************************************* | ||
| 24 | Initialization of the I2C bus interface. Need to be called only once | ||
| 25 | *************************************************************************/ | ||
| 26 | void i2c_init(void) | ||
| 27 | { | ||
| 28 | /* initialize TWI clock | ||
| 29 | * minimal values in Bit Rate Register (TWBR) and minimal Prescaler | ||
| 30 | * bits in the TWI Status Register should give us maximal possible | ||
| 31 | * I2C bus speed - about 444 kHz | ||
| 32 | * | ||
| 33 | * for more details, see 20.5.2 in ATmega16/32 secification | ||
| 34 | */ | ||
| 35 | |||
| 36 | TWSR = 0; /* no prescaler */ | ||
| 37 | TWBR = 10; /* must be >= 10 for stable operation */ | ||
| 38 | |||
| 39 | }/* i2c_init */ | ||
| 40 | |||
| 41 | |||
| 42 | /************************************************************************* | ||
| 43 | Issues a start condition and sends address and transfer direction. | ||
| 44 | return 0 = device accessible, 1= failed to access device | ||
| 45 | *************************************************************************/ | ||
| 46 | unsigned char i2c_start(unsigned char address) | ||
| 47 | { | ||
| 48 | uint8_t twst; | ||
| 49 | |||
| 50 | /* send START condition */ | ||
| 51 | TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); | ||
| 52 | |||
| 53 | /* wait until transmission completed */ | ||
| 54 | while(!(TWCR & (1<<TWINT))); | ||
| 55 | |||
| 56 | /* check value of TWI Status Register. Mask prescaler bits. */ | ||
| 57 | twst = TW_STATUS & 0xF8; | ||
| 58 | if ( (twst != TW_START) && (twst != TW_REP_START)) return 1; | ||
| 59 | |||
| 60 | /* send device address */ | ||
| 61 | TWDR = address; | ||
| 62 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 63 | |||
| 64 | /* wail until transmission completed and ACK/NACK has been received */ | ||
| 65 | while(!(TWCR & (1<<TWINT))); | ||
| 66 | |||
| 67 | /* check value of TWI Status Register. Mask prescaler bits. */ | ||
| 68 | twst = TW_STATUS & 0xF8; | ||
| 69 | if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return 1; | ||
| 70 | |||
| 71 | return 0; | ||
| 72 | |||
| 73 | }/* i2c_start */ | ||
| 74 | |||
| 75 | |||
| 76 | /************************************************************************* | ||
| 77 | Issues a start condition and sends address and transfer direction. | ||
| 78 | If device is busy, use ack polling to wait until device is ready | ||
| 79 | |||
| 80 | Input: address and transfer direction of I2C device | ||
| 81 | *************************************************************************/ | ||
| 82 | void i2c_start_wait(unsigned char address) | ||
| 83 | { | ||
| 84 | uint8_t twst; | ||
| 85 | |||
| 86 | |||
| 87 | while ( 1 ) | ||
| 88 | { | ||
| 89 | /* send START condition */ | ||
| 90 | TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); | ||
| 91 | |||
| 92 | /* wait until transmission completed */ | ||
| 93 | while(!(TWCR & (1<<TWINT))); | ||
| 94 | |||
| 95 | /* check value of TWI Status Register. Mask prescaler bits. */ | ||
| 96 | twst = TW_STATUS & 0xF8; | ||
| 97 | if ( (twst != TW_START) && (twst != TW_REP_START)) continue; | ||
| 98 | |||
| 99 | /* send device address */ | ||
| 100 | TWDR = address; | ||
| 101 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 102 | |||
| 103 | /* wail until transmission completed */ | ||
| 104 | while(!(TWCR & (1<<TWINT))); | ||
| 105 | |||
| 106 | /* check value of TWI Status Register. Mask prescaler bits. */ | ||
| 107 | twst = TW_STATUS & 0xF8; | ||
| 108 | if ( (twst == TW_MT_SLA_NACK )||(twst ==TW_MR_DATA_NACK) ) | ||
| 109 | { | ||
| 110 | /* device busy, send stop condition to terminate write operation */ | ||
| 111 | TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); | ||
| 112 | |||
| 113 | /* wait until stop condition is executed and bus released */ | ||
| 114 | while(TWCR & (1<<TWSTO)); | ||
| 115 | |||
| 116 | continue; | ||
| 117 | } | ||
| 118 | |||
| 119 | break; | ||
| 120 | } | ||
| 121 | |||
| 122 | }/* i2c_start_wait */ | ||
| 123 | |||
| 124 | |||
| 125 | /************************************************************************* | ||
| 126 | Issues a repeated start condition and sends address and transfer direction | ||
| 127 | |||
| 128 | Input: address and transfer direction of I2C device | ||
| 129 | |||
| 130 | Return: 0 device accessible | ||
| 131 | 1 failed to access device | ||
| 132 | *************************************************************************/ | ||
| 133 | unsigned char i2c_rep_start(unsigned char address) | ||
| 134 | { | ||
| 135 | return i2c_start( address ); | ||
| 136 | |||
| 137 | }/* i2c_rep_start */ | ||
| 138 | |||
| 139 | |||
| 140 | /************************************************************************* | ||
| 141 | Terminates the data transfer and releases the I2C bus | ||
| 142 | *************************************************************************/ | ||
| 143 | void i2c_stop(void) | ||
| 144 | { | ||
| 145 | /* send stop condition */ | ||
| 146 | TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); | ||
| 147 | |||
| 148 | /* wait until stop condition is executed and bus released */ | ||
| 149 | while(TWCR & (1<<TWSTO)); | ||
| 150 | |||
| 151 | }/* i2c_stop */ | ||
| 152 | |||
| 153 | |||
| 154 | /************************************************************************* | ||
| 155 | Send one byte to I2C device | ||
| 156 | |||
| 157 | Input: byte to be transfered | ||
| 158 | Return: 0 write successful | ||
| 159 | 1 write failed | ||
| 160 | *************************************************************************/ | ||
| 161 | unsigned char i2c_write( unsigned char data ) | ||
| 162 | { | ||
| 163 | uint8_t twst; | ||
| 164 | |||
| 165 | /* send data to the previously addressed device */ | ||
| 166 | TWDR = data; | ||
| 167 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 168 | |||
| 169 | /* wait until transmission completed */ | ||
| 170 | while(!(TWCR & (1<<TWINT))); | ||
| 171 | |||
| 172 | /* check value of TWI Status Register. Mask prescaler bits */ | ||
| 173 | twst = TW_STATUS & 0xF8; | ||
| 174 | if( twst != TW_MT_DATA_ACK) return 1; | ||
| 175 | return 0; | ||
| 176 | |||
| 177 | }/* i2c_write */ | ||
| 178 | |||
| 179 | |||
| 180 | /************************************************************************* | ||
| 181 | Read one byte from the I2C device, request more data from device | ||
| 182 | |||
| 183 | Return: byte read from I2C device | ||
| 184 | *************************************************************************/ | ||
| 185 | unsigned char i2c_readAck(void) | ||
| 186 | { | ||
| 187 | TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); | ||
| 188 | while(!(TWCR & (1<<TWINT))); | ||
| 189 | |||
| 190 | return TWDR; | ||
| 191 | |||
| 192 | }/* i2c_readAck */ | ||
| 193 | |||
| 194 | |||
| 195 | /************************************************************************* | ||
| 196 | Read one byte from the I2C device, read is followed by a stop condition | ||
| 197 | |||
| 198 | Return: byte read from I2C device | ||
| 199 | *************************************************************************/ | ||
| 200 | unsigned char i2c_readNak(void) | ||
| 201 | { | ||
| 202 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 203 | while(!(TWCR & (1<<TWINT))); | ||
| 204 | |||
| 205 | return TWDR; | ||
| 206 | |||
| 207 | }/* i2c_readNak */ | ||
