diff options
Diffstat (limited to 'drivers')
57 files changed, 4882 insertions, 7001 deletions
diff --git a/drivers/arm/i2c_master.c b/drivers/arm/i2c_master.c index cba5a1c679..18068d3a6d 100644 --- a/drivers/arm/i2c_master.c +++ b/drivers/arm/i2c_master.c @@ -34,98 +34,83 @@ static uint8_t i2c_address; static const I2CConfig i2cconfig = { #ifdef USE_I2CV1 - I2C1_OPMODE, - I2C1_CLOCK_SPEED, - I2C1_DUTY_CYCLE, + I2C1_OPMODE, + I2C1_CLOCK_SPEED, + I2C1_DUTY_CYCLE, #else - STM32_TIMINGR_PRESC(I2C1_TIMINGR_PRESC) | - STM32_TIMINGR_SCLDEL(I2C1_TIMINGR_SCLDEL) | STM32_TIMINGR_SDADEL(I2C1_TIMINGR_SDADEL) | - STM32_TIMINGR_SCLH(I2C1_TIMINGR_SCLH) | STM32_TIMINGR_SCLL(I2C1_TIMINGR_SCLL), - 0, - 0 + STM32_TIMINGR_PRESC(I2C1_TIMINGR_PRESC) | STM32_TIMINGR_SCLDEL(I2C1_TIMINGR_SCLDEL) | STM32_TIMINGR_SDADEL(I2C1_TIMINGR_SDADEL) | STM32_TIMINGR_SCLH(I2C1_TIMINGR_SCLH) | STM32_TIMINGR_SCLL(I2C1_TIMINGR_SCLL), 0, 0 #endif }; static i2c_status_t chibios_to_qmk(const msg_t* status) { - switch (*status) { - case I2C_NO_ERROR: - return I2C_STATUS_SUCCESS; - case I2C_TIMEOUT: - return I2C_STATUS_TIMEOUT; - // I2C_BUS_ERROR, I2C_ARBITRATION_LOST, I2C_ACK_FAILURE, I2C_OVERRUN, I2C_PEC_ERROR, I2C_SMB_ALERT - default: - return I2C_STATUS_ERROR; - } + switch (*status) { + case I2C_NO_ERROR: + return I2C_STATUS_SUCCESS; + case I2C_TIMEOUT: + return I2C_STATUS_TIMEOUT; + // I2C_BUS_ERROR, I2C_ARBITRATION_LOST, I2C_ACK_FAILURE, I2C_OVERRUN, I2C_PEC_ERROR, I2C_SMB_ALERT + default: + return I2C_STATUS_ERROR; + } } -__attribute__ ((weak)) -void i2c_init(void) -{ - // Try releasing special pins for a short time - palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_INPUT); - palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_INPUT); +__attribute__((weak)) void i2c_init(void) { + // Try releasing special pins for a short time + palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_INPUT); + palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_INPUT); - chThdSleepMilliseconds(10); + chThdSleepMilliseconds(10); #ifdef USE_I2CV1 - palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_STM32_ALTERNATE_OPENDRAIN); - palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_STM32_ALTERNATE_OPENDRAIN); + palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_STM32_ALTERNATE_OPENDRAIN); + palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_STM32_ALTERNATE_OPENDRAIN); #else - palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_ALTERNATE(I2C1_SCL_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN); - palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_ALTERNATE(I2C1_SDA_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN); + palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_ALTERNATE(I2C1_SCL_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN); + palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_ALTERNATE(I2C1_SDA_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN); #endif - //i2cInit(); //This is invoked by halInit() so no need to redo it. + // i2cInit(); //This is invoked by halInit() so no need to redo it. } -i2c_status_t i2c_start(uint8_t address) -{ - i2c_address = address; - i2cStart(&I2C_DRIVER, &i2cconfig); - return I2C_STATUS_SUCCESS; +i2c_status_t i2c_start(uint8_t address) { + i2c_address = address; + i2cStart(&I2C_DRIVER, &i2cconfig); + return I2C_STATUS_SUCCESS; } -i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout) -{ - i2c_address = address; - i2cStart(&I2C_DRIVER, &i2cconfig); - msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, 0, 0, MS2ST(timeout)); - return chibios_to_qmk(&status); +i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout) { + i2c_address = address; + i2cStart(&I2C_DRIVER, &i2cconfig); + msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, 0, 0, MS2ST(timeout)); + return chibios_to_qmk(&status); } -i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) -{ - i2c_address = address; - i2cStart(&I2C_DRIVER, &i2cconfig); - msg_t status = i2cMasterReceiveTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, MS2ST(timeout)); - return chibios_to_qmk(&status); +i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { + i2c_address = address; + i2cStart(&I2C_DRIVER, &i2cconfig); + msg_t status = i2cMasterReceiveTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, MS2ST(timeout)); + return chibios_to_qmk(&status); } -i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout) -{ - i2c_address = devaddr; - i2cStart(&I2C_DRIVER, &i2cconfig); +i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout) { + i2c_address = devaddr; + i2cStart(&I2C_DRIVER, &i2cconfig); - uint8_t complete_packet[length + 1]; - for(uint8_t i = 0; i < length; i++) - { - complete_packet[i+1] = data[i]; - } - complete_packet[0] = regaddr; + uint8_t complete_packet[length + 1]; + for (uint8_t i = 0; i < length; i++) { + complete_packet[i + 1] = data[i]; + } + complete_packet[0] = regaddr; - msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), complete_packet, length + 1, 0, 0, MS2ST(timeout)); - return chibios_to_qmk(&status); + msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), complete_packet, length + 1, 0, 0, MS2ST(timeout)); + return chibios_to_qmk(&status); } -i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) -{ - i2c_address = devaddr; - i2cStart(&I2C_DRIVER, &i2cconfig); - msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), ®addr, 1, data, length, MS2ST(timeout)); - return chibios_to_qmk(&status); +i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { + i2c_address = devaddr; + i2cStart(&I2C_DRIVER, &i2cconfig); + msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), ®addr, 1, data, length, MS2ST(timeout)); + return chibios_to_qmk(&status); } -void i2c_stop(void) -{ - i2cStop(&I2C_DRIVER); -} +void i2c_stop(void) { i2cStop(&I2C_DRIVER); } diff --git a/drivers/arm/i2c_master.h b/drivers/arm/i2c_master.h index c8afa31e28..b40fa0a910 100644 --- a/drivers/arm/i2c_master.h +++ b/drivers/arm/i2c_master.h @@ -27,84 +27,83 @@ #include "ch.h" #include <hal.h> - #if defined(STM32F1XX) || defined(STM32F1xx) || defined(STM32F2xx) || defined(STM32F4xx) || defined(STM32L0xx) || defined(STM32L1xx) - #define USE_I2CV1 +# define USE_I2CV1 #endif #ifdef I2C1_BANK - #define I2C1_SCL_BANK I2C1_BANK - #define I2C1_SDA_BANK I2C1_BANK +# define I2C1_SCL_BANK I2C1_BANK +# define I2C1_SDA_BANK I2C1_BANK #endif #ifndef I2C1_SCL_BANK - #define I2C1_SCL_BANK GPIOB +# define I2C1_SCL_BANK GPIOB #endif #ifndef I2C1_SDA_BANK - #define I2C1_SDA_BANK GPIOB +# define I2C1_SDA_BANK GPIOB #endif #ifndef I2C1_SCL - #define I2C1_SCL 6 +# define I2C1_SCL 6 #endif #ifndef I2C1_SDA - #define I2C1_SDA 7 +# define I2C1_SDA 7 #endif #ifdef USE_I2CV1 - #ifndef I2C1_OPMODE - #define I2C1_OPMODE OPMODE_I2C - #endif - #ifndef I2C1_CLOCK_SPEED - #define I2C1_CLOCK_SPEED 100000 /* 400000 */ - #endif - #ifndef I2C1_DUTY_CYCLE - #define I2C1_DUTY_CYCLE STD_DUTY_CYCLE /* FAST_DUTY_CYCLE_2 */ - #endif +# ifndef I2C1_OPMODE +# define I2C1_OPMODE OPMODE_I2C +# endif +# ifndef I2C1_CLOCK_SPEED +# define I2C1_CLOCK_SPEED 100000 /* 400000 */ +# endif +# ifndef I2C1_DUTY_CYCLE +# define I2C1_DUTY_CYCLE STD_DUTY_CYCLE /* FAST_DUTY_CYCLE_2 */ +# endif #else - // The default PAL alternate modes are used to signal that the pins are used for I2C - #ifndef I2C1_SCL_PAL_MODE - #define I2C1_SCL_PAL_MODE 4 - #endif - #ifndef I2C1_SDA_PAL_MODE - #define I2C1_SDA_PAL_MODE 4 - #endif +// The default PAL alternate modes are used to signal that the pins are used for I2C +# ifndef I2C1_SCL_PAL_MODE +# define I2C1_SCL_PAL_MODE 4 +# endif +# ifndef I2C1_SDA_PAL_MODE +# define I2C1_SDA_PAL_MODE 4 +# endif - // The default timing values below configures the I2C clock to 400khz assuming a 72Mhz clock - // For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html - #ifndef I2C1_TIMINGR_PRESC - #define I2C1_TIMINGR_PRESC 15U - #endif - #ifndef I2C1_TIMINGR_SCLDEL - #define I2C1_TIMINGR_SCLDEL 4U - #endif - #ifndef I2C1_TIMINGR_SDADEL - #define I2C1_TIMINGR_SDADEL 2U - #endif - #ifndef I2C1_TIMINGR_SCLH - #define I2C1_TIMINGR_SCLH 15U - #endif - #ifndef I2C1_TIMINGR_SCLL - #define I2C1_TIMINGR_SCLL 21U - #endif +// The default timing values below configures the I2C clock to 400khz assuming a 72Mhz clock +// For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html +# ifndef I2C1_TIMINGR_PRESC +# define I2C1_TIMINGR_PRESC 15U +# endif +# ifndef I2C1_TIMINGR_SCLDEL +# define I2C1_TIMINGR_SCLDEL 4U +# endif +# ifndef I2C1_TIMINGR_SDADEL +# define I2C1_TIMINGR_SDADEL 2U +# endif +# ifndef I2C1_TIMINGR_SCLH +# define I2C1_TIMINGR_SCLH 15U +# endif +# ifndef I2C1_TIMINGR_SCLL +# define I2C1_TIMINGR_SCLL 21U +# endif #endif #ifndef I2C_DRIVER - #define I2C_DRIVER I2CD1 +# define I2C_DRIVER I2CD1 #endif typedef int16_t i2c_status_t; #define I2C_STATUS_SUCCESS (0) -#define I2C_STATUS_ERROR (-1) +#define I2C_STATUS_ERROR (-1) #define I2C_STATUS_TIMEOUT (-2) -void i2c_init(void); +void i2c_init(void); i2c_status_t i2c_start(uint8_t address); i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout); i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout); -i2c_status_t i2c_transmit_receive(uint8_t address, uint8_t * tx_body, uint16_t tx_length, uint8_t * rx_body, uint16_t rx_length); +i2c_status_t i2c_transmit_receive(uint8_t address, uint8_t* tx_body, uint16_t tx_length, uint8_t* rx_body, uint16_t rx_length); i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout); i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout); -void i2c_stop(void); +void i2c_stop(void); diff --git a/drivers/avr/analog.c b/drivers/avr/analog.c index 1ec38df75d..1a8da4261d 100644 --- a/drivers/avr/analog.c +++ b/drivers/avr/analog.c @@ -21,49 +21,38 @@ #include <stdint.h> #include "analog.h" +static uint8_t aref = (1 << REFS0); // default to AREF = Vcc -static uint8_t aref = (1<<REFS0); // default to AREF = Vcc - - -void analogReference(uint8_t mode) -{ - aref = mode & 0xC0; -} - +void analogReference(uint8_t mode) { aref = mode & 0xC0; } // Arduino compatible pin input -int16_t analogRead(uint8_t pin) -{ +int16_t analogRead(uint8_t pin) { #if defined(__AVR_ATmega32U4__) - static const uint8_t PROGMEM pin_to_mux[] = { - 0x00, 0x01, 0x04, 0x05, 0x06, 0x07, - 0x25, 0x24, 0x23, 0x22, 0x21, 0x20}; - if (pin >= 12) return 0; - return adc_read(pgm_read_byte(pin_to_mux + pin)); + static const uint8_t PROGMEM pin_to_mux[] = {0x00, 0x01, 0x04, 0x05, 0x06, 0x07, 0x25, 0x24, 0x23, 0x22, 0x21, 0x20}; + if (pin >= 12) return 0; + return adc_read(pgm_read_byte(pin_to_mux + pin)); #elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__) - if (pin >= 8) return 0; - return adc_read(pin); + if (pin >= 8) return 0; + return adc_read(pin); #else - return 0; + return 0; #endif } // Mux input -int16_t adc_read(uint8_t mux) -{ +int16_t adc_read(uint8_t mux) { #if defined(__AVR_AT90USB162__) - return 0; + return 0; #else - uint8_t low; - - ADCSRA = (1<<ADEN) | ADC_PRESCALER; // enable ADC - ADCSRB = (1<<ADHSM) | (mux & 0x20); // high speed mode - ADMUX = aref | (mux & 0x1F); // configure mux input - ADCSRA = (1<<ADEN) | ADC_PRESCALER | (1<<ADSC); // start the conversion - while (ADCSRA & (1<<ADSC)) ; // wait for result - low = ADCL; // must read LSB first - return (ADCH << 8) | low; // must read MSB only once! + uint8_t low; + + ADCSRA = (1 << ADEN) | ADC_PRESCALER; // enable ADC + ADCSRB = (1 << ADHSM) | (mux & 0x20); // high speed mode + ADMUX = aref | (mux & 0x1F); // configure mux input + ADCSRA = (1 << ADEN) | ADC_PRESCALER | (1 << ADSC); // start the conversion + while (ADCSRA & (1 << ADSC)) + ; // wait for result + low = ADCL; // must read LSB first + return (ADCH << 8) | low; // must read MSB only once! #endif } - - diff --git a/drivers/avr/analog.h b/drivers/avr/analog.h index 8d93de7dc2..32452a1ec2 100644 --- a/drivers/avr/analog.h +++ b/drivers/avr/analog.h @@ -19,34 +19,34 @@ #include <stdint.h> -void analogReference(uint8_t mode); +void analogReference(uint8_t mode); int16_t analogRead(uint8_t pin); int16_t adc_read(uint8_t mux); -#define ADC_REF_POWER (1<<REFS0) -#define ADC_REF_INTERNAL ((1<<REFS1) | (1<<REFS0)) -#define ADC_REF_EXTERNAL (0) +#define ADC_REF_POWER (1 << REFS0) +#define ADC_REF_INTERNAL ((1 << REFS1) | (1 << REFS0)) +#define ADC_REF_EXTERNAL (0) // These prescaler values are for high speed mode, ADHSM = 1 #if F_CPU == 16000000L -#define ADC_PRESCALER ((1<<ADPS2) | (1<<ADPS1)) +# define ADC_PRESCALER ((1 << ADPS2) | (1 << ADPS1)) #elif F_CPU == 8000000L -#define ADC_PRESCALER ((1<<ADPS2) | (1<<ADPS0)) +# define ADC_PRESCALER ((1 << ADPS2) | (1 << ADPS0)) #elif F_CPU == 4000000L -#define ADC_PRESCALER ((1<<ADPS2)) +# define ADC_PRESCALER ((1 << ADPS2)) #elif F_CPU == 2000000L -#define ADC_PRESCALER ((1<<ADPS1) | (1<<ADPS0)) +# define ADC_PRESCALER ((1 << ADPS1) | (1 << ADPS0)) #elif F_CPU == 1000000L -#define ADC_PRESCALER ((1<<ADPS1)) +# define ADC_PRESCALER ((1 << ADPS1)) #else -#define ADC_PRESCALER ((1<<ADPS0)) +# define ADC_PRESCALER ((1 << ADPS0)) #endif // some avr-libc versions do not properly define ADHSM #if defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__) -#if !defined(ADHSM) -#define ADHSM (7) -#endif +# if !defined(ADHSM) +# define ADHSM (7) +# endif #endif #endif diff --git a/drivers/avr/apa102.c b/drivers/avr/apa102.c index 55a0d57778..f4d97a1589 100755..100644 --- a/drivers/avr/apa102.c +++ b/drivers/avr/apa102.c @@ -1,24 +1,24 @@ /* -* APA102 lib V1.0a -* -* Controls APA102 RGB-LEDs -* Author: Mikkel (Duckle29 on github) -* -* Dec 22th, 2017 v1.0a Initial Version -* -* This program is free software: you can redistribute it and/or modify -* it under the terms of the GNU General Public License as published by -* the Free Software Foundation, either version 2 of the License, or -* (at your option) any later version. -* -* This program is distributed in the hope that it will be useful, -* but WITHOUT ANY WARRANTY; without even the implied warranty of -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -* GNU General Public License for more details. -* -* You should have received a copy of the GNU General Public License -* along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ + * APA102 lib V1.0a + * + * Controls APA102 RGB-LEDs + * Author: Mikkel (Duckle29 on github) + * + * Dec 22th, 2017 v1.0a Initial Version + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ #include "apa102.h" #include <avr/interrupt.h> @@ -27,75 +27,70 @@ #include "debug.h" // Setleds for standard RGB -void inline apa102_setleds(LED_TYPE *ledarray, uint16_t leds){ - apa102_setleds_pin(ledarray,leds, _BV(RGB_DI_PIN & 0xF), _BV(RGB_CLK_PIN & 0xF)); -} +void inline apa102_setleds(LED_TYPE *ledarray, uint16_t leds) { apa102_setleds_pin(ledarray, leds, _BV(RGB_DI_PIN & 0xF), _BV(RGB_CLK_PIN & 0xF)); } -void static inline apa102_setleds_pin(LED_TYPE *ledarray, uint16_t leds, uint8_t pinmask_DI, uint8_t pinmask_CLK){ - pinMode(RGB_DI_PIN, PinDirectionOutput); - pinMode(RGB_CLK_PIN, PinDirectionOutput); +void static inline apa102_setleds_pin(LED_TYPE *ledarray, uint16_t leds, uint8_t pinmask_DI, uint8_t pinmask_CLK) { + pinMode(RGB_DI_PIN, PinDirectionOutput); + pinMode(RGB_CLK_PIN, PinDirectionOutput); - apa102_send_array((uint8_t*)ledarray,leds) + apa102_send_array((uint8_t *)ledarray, leds) } -void apa102_send_array(uint8_t *data, uint16_t leds){ // Data is struct of 3 bytes. RGB - leds is number of leds in data - apa102_start_frame(); - while(leds--){ - apa102_send_frame(0xFF000000 | (data->b << 16) | (data->g << 8) | data->r); - data++; - } - apa102_end_frame(leds); +void apa102_send_array(uint8_t *data, uint16_t leds) { // Data is struct of 3 bytes. RGB - leds is number of leds in data + apa102_start_frame(); + while (leds--) { + apa102_send_frame(0xFF000000 | (data->b << 16) | (data->g << 8) | data->r); + data++; + } + apa102_end_frame(leds); } -void apa102_send_frame(uint32_t frame){ - for(uint32_t i=0xFF; i>0;){ - apa102_send_byte(frame & i); - i = i << 8; - } +void apa102_send_frame(uint32_t frame) { + for (uint32_t i = 0xFF; i > 0;) { + apa102_send_byte(frame & i); + i = i << 8; + } } -void apa102_start_frame(){ - apa102_send_frame(0); -} +void apa102_start_frame() { apa102_send_frame(0); } -void apa102_end_frame(uint16_t leds) -{ - // This function has been taken from: https://github.com/pololu/apa102-arduino/blob/master/APA102.h - // and adapted. The code is MIT licensed. I think thats compatible? +void apa102_end_frame(uint16_t leds) { + // This function has been taken from: https://github.com/pololu/apa102-arduino/blob/master/APA102.h + // and adapted. The code is MIT licensed. I think thats compatible? - // We need to send some more bytes to ensure that all the LEDs in the - // chain see their new color and start displaying it. - // - // The data stream seen by the last LED in the chain will be delayed by - // (count - 1) clock edges, because each LED before it inverts the clock - // line and delays the data by one clock edge. Therefore, to make sure - // the last LED actually receives the data we wrote, the number of extra - // edges we send at the end of the frame must be at least (count - 1). - // For the APA102C, that is sufficient. - // - // The SK9822 only updates after it sees 32 zero bits followed by one more - // rising edge. To avoid having the update time depend on the color of - // the last LED, we send a dummy 0xFF byte. (Unfortunately, this means - // that partial updates of the beginning of an LED strip are not possible; - // the LED after the last one you are trying to update will be black.) - // After that, to ensure that the last LED in the chain sees 32 zero bits - // and a rising edge, we need to send at least 65 + (count - 1) edges. It - // is sufficent and simpler to just send (5 + count/16) bytes of zeros. - // - // We are ignoring the specification for the end frame in the APA102/SK9822 - // datasheets because it does not actually ensure that all the LEDs will - // start displaying their new colors right away. + // We need to send some more bytes to ensure that all the LEDs in the + // chain see their new color |