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https://github.com/Keychron/qmk_firmware.git
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Update i2c.c
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092416325b
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@ -161,94 +161,4 @@ ISR(TWI_vect) {
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TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
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}
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// from SSD1306
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/*
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void i2c_start_wait(unsigned char address)
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{
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uint8_t twst;
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while ( 1 )
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{
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// send START condition
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TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
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// wait until transmission completed
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while(!(TWCR & (1<<TWINT)));
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// check value of TWI Status Register. Mask prescaler bits.
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twst = TW_STATUS & 0xF8;
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if ( (twst != TW_START) && (twst != TW_REP_START)) continue;
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// send device address
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TWDR = address;
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TWCR = (1<<TWINT) | (1<<TWEN);
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// wail until transmission completed
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while(!(TWCR & (1<<TWINT)));
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// check value of TWI Status Register. Mask prescaler bits.
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twst = TW_STATUS & 0xF8;
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if ( (twst == TW_MT_SLA_NACK )||(twst ==TW_MR_DATA_NACK) )
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{
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// device busy, send stop condition to terminate write operation
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TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
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// wait until stop condition is executed and bus released
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while(TWCR & (1<<TWSTO));
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continue;
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}
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//if( twst != TW_MT_SLA_ACK) return 1;
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break;
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}
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}// i2c_start_wait
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*/
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/*************************************************************************
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Issues a repeated start condition and sends address and transfer direction
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Input: address and transfer direction of I2C device
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Return: 0 device accessible
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1 failed to access device
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*************************************************************************/
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/*
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unsigned char i2c_rep_start(unsigned char address)
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{
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return i2c_master_start( address );
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}/* i2c_rep_start */
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/*************************************************************************
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Read one byte from the I2C device, request more data from device
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Return: byte read from I2C device
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*************************************************************************/
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/*
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unsigned char i2c_readAck(void)
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{
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TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
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while(!(TWCR & (1<<TWINT)));
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return TWDR;
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}/* i2c_readAck */
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/*************************************************************************
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Read one byte from the I2C device, read is followed by a stop condition
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Return: byte read from I2C device
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*************************************************************************
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unsigned char i2c_readNak(void)
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{
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TWCR = (1<<TWINT) | (1<<TWEN);
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while(!(TWCR & (1<<TWINT)));
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return TWDR;
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}/* i2c_readNak */
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#endif
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