GY-63_MS5611/libraries/PCA9634/README.md

PCA9634

Arduino library for PCA9634 I2C 8 bit PWM LED driver, 8 channel.

Description

This library is to control the I2C PCA9634 PWM extender. The 8 channels are independently configurable in steps of 1/256. this allows for better than 1% fine tuning of the duty-cycle of the PWM signal.

library is a 8 channel derived variation of the PCA9635 class. (these might merge in the future)

Interface

Constructor

• PCA9634(uint8_t deviceAddress, TwoWire *wire = &Wire) Constructor with I2C device address, and optional the Wire interface as parameter.
• bool begin(uint8_t mode1_mask = PCA9634_MODE1_ALLCALL, uint8_t mode2_mask = PCA9634_MODE2_NONE) initializes the library after startup. Optionally setting the MODE1 and MODE2 configuration registers. See PCA9634.h and datasheet for settings possible.
• bool begin(int sda, int scl, uint8_t mode1_mask = PCA9634_MODE1_ALLCALL, uint8_t mode2_mask = PCA9634_MODE2_NONE) idem, ESP32 ESP8266 only.
• void configure(uint8_t mode1_mask, uint8_t mode2_mask) To configure the library after startup one can set the MODE1 and MODE2 configuration registers. See PCA9634.h and datasheet for settings possible.
• bool isConnected() checks if address is visible on I2C bus.
• uint8_t channelCount() returns the number of channels = 8.

LedDriverMode

Configure LED behaviour.

• uint8_t setLedDriverMode(uint8_t channel, uint8_t mode) mode is 0..3 See datasheet for full details.
• uint8_t getLedDriverMode(uint8_t channel) returns the current mode of the channel.

LED mode	Value	Description
PCA9634_LEDOFF	0x00	led is 100% off, default @startup
PCA9634_LEDON	0x01	led is 100% on.
PCA9634_LEDPWM	0x02	set LED in PWM mode, 0..255
PCA9634_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

Read and write individual values to LED channels. Requires LEDs' DriverMode of the specific channels to be in PWM mode.

• uint8_t write1(uint8_t channel, uint8_t value) writes a single 8 bit PWM value.
• uint8_t write3(uint8_t channel, uint8_t R, uint8_t G, uint8_t B) writes three consecutive PWM registers. typical use is to write R, G, B values for a full colour LED.
• uint8_t writeN(uint8_t channel, uint8_t * array, uint8_t count) write count consecutive PWM registers. May return PCA9634_ERR_WRITE if array has too many elements (including channel as offset).

Mode registers

Used to configure the PCA963x general behaviour.

• uint8_t writeMode(uint8_t reg, uint8_t value) configuration of one of the two configuration registers. Check datasheet for details.
• uint8_t readMode(uint8_t reg) reads back the configured mode, useful to add or remove a single flag (bit masking).
• uint8_t setMode1(uint8_t value) convenience wrapper.
• uint8_t setMode2(uint8_t value) convenience wrapper.
• uint8_t getMode1() convenience wrapper.
• uint8_t getMode2() convenience wrapper.

Constants for mode registers

(added 0.1.2)

Name	Value	Description
PCA9634_MODE1_AUTOINCR2	0x80	Read Only, 0 = disable 1 = enable
PCA9634_MODE1_AUTOINCR1	0x40	Read Only, bit1
PCA9634_MODE1_AUTOINCR0	0x20	Read Only, bit0
PCA9634_MODE1_SLEEP	0x10	0 = normal 1 = sleep
PCA9634_MODE1_SUB1	0x08	0 = disable 1 = enable
PCA9634_MODE1_SUB2	0x04	0 = disable 1 = enable
PCA9634_MODE1_SUB3	0x02	0 = disable 1 = enable
PCA9634_MODE1_ALLCALL	0x01	0 = disable 1 = enable
PCA9634_MODE1_NONE	0x00
PCA9634_MODE2_BLINK	0x20	0 = dim 1 = blink
PCA9634_MODE2_INVERT	0x10	0 = normal 1 = inverted
PCA9634_MODE2_STOP	0x08	0 = on STOP 1 = on ACK
PCA9634_MODE2_TOTEMPOLE	0x04	0 = open drain 1 = totem-pole
PCA9634_MODE2_NONE	0x00

These constants makes it easier to set modes without using a non descriptive bit mask. The constants can be merged by OR-ing them together, see snippet:

ledArray.writeMode(PCA9634_MODE2, 0b00110100);

// would become

uint8_t mode2_mask = PCA9634_MODE2_BLINK | PCA9634_MODE2_INVERT | PCA9634_MODE2_TOTEMPOLE;
ledArray.writeMode(PCA9634_MODE2, mode2_mask);

// or even

ledArray.setMode2(PCA9634_MODE2_BLINK | PCA9634_MODE2_INVERT | PCA9634_MODE2_TOTEMPOLE);

Group PWM and frequency

Check datasheet for the details.

• void setGroupPWM(uint8_t value) sets all channels that are part of the PWM group to value.
• uint8_t getGroupPWM() get the current PWM setting of the group.
• void setGroupFREQ(uint8_t value) is used for blinking the group of configured LED. Value goes from 0 to 255 with each step representing an increase of approx. 41 ms. So 0x00 results in 41 ms blinking period (on AND off) and 0xFF in approx. 10.5 s.
• uint8_t getGroupFREQ() returns the set frequency of the PWM group.

Miscellaneous

• int lastError() returns PCA9634_OK if all is OK, and other error codes otherwise.

Error code	Value	Description
PCA9634_OK	0x00	Everything went well
PCA9634_ERROR	0xFF	Generic error
PCA9634_ERR_WRITE	0xFE	Tries to write more elements than PWM channels
PCA9634_ERR_CHAN	0xFD	Channel out of range
PCA9634_ERR_MODE	0xFC	Invalid mode
PCA9634_ERR_REG	0xFB	Invalid register
PCA9634_ERR_I2C	0xFA	I2C communication error

SUB CALL and ALL CALL

Please read the datasheet to understand the working of SUB CALL and ALL CALL.

Since version 0.2.0 there is (experimental) support for the SUB CALL and ALL CALL functions. It needs more testing and if there are issues, please report.

AllCall is automatically activated for each device on startup.

Description

SUB CALL allows one to make groups of PCA9634 devices and control them on group level. The number of groups one can make depends on free I2C addresses on one I2C bus. Using multiple I2C buses or multiplexers will even increase the possible number. Every PCA9634 device can be member of up to three of these groups. To become member one needs to set the setSubCallAddress(nr, address) and enable it with enableSubCall(nr).

In the same way one can become member of an ALL CALL group. Typically there is only one such group but one can configure more of them by applying different addresses.

Interface

The functions to enable all/sub-addresses are straightforward:

• bool enableSubCall(uint8_t nr) nr = 1,2,3

• bool disableSubCall(uint8_t nr) nr = 1,2,3

• bool isEnabledSubCall(uint8_t nr) nr = 1,2,3

• bool setSubCallAddress(uint8_t nr, uint8_t address)

• uint8_t getSubCallAddress(uint8_t nr)

• bool enableAllCall()

• bool disableAllCall()

• bool isEnabledAllCall()

• bool setAllCallAddress(uint8_t address)

• uint8_t getAllCallAddress()

I2C Software reset

The goal of this function is to reset ALL PCA9634 devices on the bus. When using the software reset, ALL devices attached to the bus are set to their hardware startup conditions. Generally, there are multiple definitions of software resets by the I²C inventor NXP. To accommodate this, two different modes for this function have been defined and tested (library version 0.2.2).

• Method 1 is a tested method which is specific to the PCA9634. Since the number of different types of I²C chips is very large, side-effects on other chips might be possible. Before using this method, consult the data sheets of all chips on the bus to mitigate potential undefined states.
• Method 0 is a somewhat “general” method which resets many chips on the I²C-bus. However, this method DOES NOT reset the PCA9634 chip. Therefore, consult the data sheet of all different chips on the bus to mitigate potential undefined states.

When only working with PCA9634 chips on a bus, only method 1 is required.

ledArray.I2C_SoftwareReset(1); // for method 1
ledArray.I2C_SoftwareReset(0); // for method 0

In case you experience issues with this function on your chips (non-PCA9634), please give feedback, so the documentation can be improved.

For further details of the development, see - #10 (comment)

Operation

See examples

Future

must

• improve documentation

should

• unit tests
  • SUB CALL if possible?
  • ALL CALL if possible?
• add examples

could

• sync with PCA9635 developments
• merge with PCA9635 and a PCA963X base class if possible