PCA9635

Arduino library for PCA9635 I2C 8 bit PWM LED driver

Description

This library is to control the I2C PCA9635 PWM extender. The 16 channels are independently configurable is steps of 1/256. this allows for better than 1% finetuning of the duty-cycle of the PWM signal.

Interface

Constructor

PCA9635(deviceAddress, TwoWire *wire = &Wire) Constructor with I2C device address, and optional the Wire interface as parameter.
begin() initializes the library after startup. Mandatory.
begin(sda, scl) idem, ESP32 ESP8266 only. Library does not support multiple Wire instances (yet).
reset() resets the library to start up conditions.
isConnected() checks if address is available on I2C bus.

LedDriverMode

setLedDriverMode(channel, mode) mode is 0..3 See datasheet for full details.
getLedDriverMode(channel) returns the current mode of the channel.

LED mode	Value	Description
PCA9635_LEDOFF	0x00	led is 100% off, default @startup
PCA9635_LEDON	0x01	led is 100% on.
PCA9635_LEDPWM	0x02	set LED in PWM mode, 0..255
PCA9635_LEDGRPPWM	0x03	add LED to the GRPPWM*

* all leds in the group GRPPWM can be set to the same PWM value in one set. This is ideal to trigger e.g. multiple LEDS (servo's) at same time.

Read and write

write1(channel, value) writes a single 8 bit PWM value.
write3(channel, R, G, B) writes three consecutive PWM registers.
writeN(channel, array, count) write count consecutive PWM registers. May return PCA9635_ERR_WRITE if array has too many elements (including channel as offset)
writeMode(reg, mode) configuration of one of the two configuration registers. check datasheet for details.
readMode(reg) reads back the configured mode, useful to add or remove a single flag (bit masking)

Group PWM and frequency

setGroupPWM(uint8_t value) sets all channels that are part of the PWM group to value.
getGroupPWM() get the current PWM setting of the group.
setGroupFREQ(value) see datasheet for details.
getGroupFREQ() returns the freq of the PWM group.

Misc

lastError() returns PCA9635_OK if all is OK, and other error codes otherwise.

Error code	Value	Description
PCA9635_OK	0x00	Everything went well
PCA9635_ERROR	0xFF	Generic error
PCA9635_ERR_WRITE	0xFE	Tries to write more elements than PWM channels
PCA9635_ERR_CHAN	0xFD	Channel out of range
PCA9635_ERR_MODE	0xFC	Invalid mode
PCA9635_ERR_REG	0xFB	Invalid register
PCA9635_ERR_I2C	0xFA	PCA9635 I2C communication error

Operation

See examples

3.1 KiB Raw Blame History