mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
328 lines
13 KiB
Markdown
328 lines
13 KiB
Markdown
|
||
[![Arduino CI](https://github.com/RobTillaart/PCA9685_RT/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
|
||
[![Arduino-lint](https://github.com/RobTillaart/PCA9685_RT/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/PCA9685_RT/actions/workflows/arduino-lint.yml)
|
||
[![JSON check](https://github.com/RobTillaart/PCA9685_RT/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/PCA9685_RT/actions/workflows/jsoncheck.yml)
|
||
[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/PCA9685_RT.svg)](https://github.com/RobTillaart/PCA9685_RT/issues)
|
||
|
||
[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/PCA9685_RT/blob/master/LICENSE)
|
||
[![GitHub release](https://img.shields.io/github/release/RobTillaart/PCA9685_RT.svg?maxAge=3600)](https://github.com/RobTillaart/PCA9685_RT/releases)
|
||
[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/PCA9685.svg)](https://registry.platformio.org/libraries/robtillaart/PCA9685)
|
||
|
||
|
||
# PCA9685_RT
|
||
|
||
Arduino library for PCA9685 I2C LED driver, 16 channel PWM, 12 bit.
|
||
|
||
|
||
## Description
|
||
|
||
This library is to control the I2C PCA9685 PWM extender.
|
||
The 16 channels are independently configurable in steps of 1/4096.
|
||
This allows for better than 0.1% fine tuning of the duty-cycle
|
||
of the PWM signal.
|
||
|
||
The PWM's of the different channels have individual start and stop moments.
|
||
This can be used to distribute the power more evenly over multiple servo's
|
||
or give special effects when used in an RGB LED.
|
||
|
||
The frequency of the PWM can be set from 24 to 1526 according to the datasheet,
|
||
however in practice not all frequencies are set accurate.
|
||
Lower frequencies do better than higher frequencies.
|
||
|
||
|
||
|
||
#### 0.7.0 Breaking change
|
||
|
||
The version 0.7.0 has breaking changes in the interface.
|
||
The rationale is that the programming environment of the **Arduino ESP32 S3**
|
||
board uses a remapping by means of the include file **io_pin_remap.h**.
|
||
This file remaps the pins of several core Arduino functions.
|
||
The remapping is implemented by #define macros and these implement "hard" text
|
||
replacements without considering context.
|
||
The effect is that methods from this class (and several others) which have the same
|
||
name as those Arduino core functions will be remapped into something not working.
|
||
|
||
The following library functions have been renamed:
|
||
|
||
| old name | new name | notes |
|
||
|:-----------------|:-------------|:--------|
|
||
| analogRead() | read() |
|
||
| analogWrite() | write() |
|
||
| pinMode() | pinMode1() |
|
||
| digitalRead() | read1() |
|
||
| digitalWrite() | write1() |
|
||
|
||
|
||
#### 0.6.0 Breaking change
|
||
|
||
Version 0.6.0 introduced a breaking change.
|
||
You cannot set the pins in **begin()** any more.
|
||
This reduces the dependency of processor dependent Wire implementations.
|
||
The user has to call **Wire.begin()** and can optionally set the Wire pins
|
||
before calling **begin()**.
|
||
|
||
|
||
#### Related
|
||
|
||
- https://github.com/RobTillaart/PCA9634 (8 channel)
|
||
- https://github.com/RobTillaart/PCA9635 (16 channel)
|
||
- https://github.com/RobTillaart/PCA9685_RT (16 channel)
|
||
|
||
|
||
## Interface
|
||
|
||
```cpp
|
||
#include "PCA9685.h"
|
||
```
|
||
|
||
### Constructor
|
||
|
||
- **PCA9685(uint8_t deviceAddress, TwoWire \* wire = &Wire)** Constructor with I2C device address,
|
||
and optional the Wire interface as parameter.
|
||
- **bool begin(uint8_t mode1_mask = PCA9685_MODE1_AUTOINCR | PCA9685_MODE1_ALLCALL, uint8_t mode2_mask = PCA9685_MODE2_TOTEMPOLE)**
|
||
initializes the library after startup. Optionally setting the MODE1 and MODE2 configuration registers.
|
||
See PCA9685.h and datasheet for settings possible.
|
||
- **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 PCA9685.h and datasheet for settings possible.
|
||
- **bool isConnected()** checks if address is available on I2C bus.
|
||
- **uint8_t channelCount()** returns the number of channels = 16.
|
||
|
||
|
||
### Mode registers
|
||
|
||
Used to configure the PCA9685 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 0.4.0)
|
||
|
||
| Name | Value | Description |
|
||
|:------------------------|:-----:|:-----------------------------------|
|
||
| PCA9685_MODE1_RESTART | 0x80 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_EXTCLK | 0x40 | 0 = internal 1 = external |
|
||
| PCA9685_MODE1_AUTOINCR | 0x20 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_SLEEP | 0x10 | 0 = normal 1 = sleep |
|
||
| PCA9685_MODE1_SUB1 | 0x08 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_SUB2 | 0x04 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_SUB3 | 0x02 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_ALLCALL | 0x01 | 0 = disable 1 = enable |
|
||
| PCA9685_MODE1_NONE | 0x00 | |
|
||
| | | |
|
||
| PCA9685_MODE2_INVERT | 0x10 | 0 = normal 1 = inverted |
|
||
| PCA9685_MODE2_STOP | 0x08 | 0 = on STOP 1 = on ACK |
|
||
| PCA9685_MODE2_TOTEMPOLE | 0x04 | 0 = open drain 1 = totem-pole |
|
||
| PCA9685_MODE2_OUTNE | 0x03 | check datasheet |
|
||
| PCA9685_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:
|
||
|
||
```cpp
|
||
ledArray.writeMode(PCA9685_MODE2, 0b00010100);
|
||
|
||
// would become
|
||
|
||
uint8_t mode2_mask = PCA9685_MODE2_INVERT | PCA9685_MODE2_TOTEMPOLE;
|
||
ledArray.writeMode(PCA9685_MODE2, mode2_mask);
|
||
|
||
// or even
|
||
|
||
ledArray.setMode2(PCA9685_MODE2_INVERT | PCA9685_MODE2_TOTEMPOLE);
|
||
|
||
```
|
||
|
||
### PWM
|
||
|
||
- **void setPWM(uint8_t channel, uint16_t onTime, uint16_t offTime)** The chip has 16 channels to do PWM.
|
||
The signal is divided in 4096 steps, 0..4095.
|
||
The pulse can begin **onTime** on any step and it can stop on any step **offTime**.
|
||
This allows e.g. to distribute the power over the 16 channels, e.g. the
|
||
channels do not need to start at the same moment with HIGH.
|
||
- **void setPWM(uint8_t channel, offTime)** simple PWM that always start on **onTime = 0**.
|
||
- **void getPWM(uint8_t channel, uint16_t \* onTime, uint16_t \* offTime)**
|
||
read back the configuration of the channel.
|
||
- **void allOFF()** switches all PWM channels OFF. **Experimental** in 0.3.0.
|
||
To "undo" the allOFF one can call the **reset()** function and set all
|
||
PWM channels again.
|
||
- **void write1(channel, mode)** mode = HIGH or LOW, just use the PCA9685 as
|
||
a digital pin, write 1 bit.
|
||
This single function replaces the setON() and setOFF() that will become
|
||
obsolete in the future.
|
||
|
||
|
||
### Frequency
|
||
|
||
- **void setFrequency(uint16_t freq, int offset = 0)** set the update speed of the channels.
|
||
This value is set the same for all channels at once.
|
||
- **int getFrequency(bool cache = true)** get the current update frequency of the channels.
|
||
This is same for all channels. If cache is false, the frequency is fetched and
|
||
calculated from the **preScaler** register and will probably differ from the
|
||
value set with **setFrequency()**.
|
||
|
||
The frequency is constrained to be between 24 and 1526 Hz.
|
||
As the frequency is converted to an 8 bit **preScaler**,
|
||
the frequency set will seldom be exact.
|
||
After changing the frequency, one must set all channels (again),
|
||
so one should set the frequency in **setup()**
|
||
|
||
The parameter offset can be used to tune the **preScaler** to get a frequency
|
||
closer to the requested value. See **PCA9685_setFrequency_offset** example.
|
||
Default the offset = 0. As the **preScaler** is smaller at higher frequencies
|
||
higher frequencies are less accurate.
|
||
Making offset too large can result in very incorrect frequencies.
|
||
|
||
When using offset, the **getFrequency(false)** will return the adjusted **preScaler**.
|
||
|
||
|
||
### Miscellaneous
|
||
|
||
- **int lastError()** returns **PCA9685_OK = 0** if all is OK, and
|
||
|
||
| Error code | Value | Description |
|
||
|:--------------------|:-----:|:------------|
|
||
| PCA9685_OK | 0x00 | Everything went well
|
||
| PCA9685_ERROR | 0xFF | generic error
|
||
| PCA9685_ERR_CHANNEL | 0xFE | Channel out of range
|
||
| PCA9685_ERR_MODE | 0xFD | Invalid mode register chosen |
|
||
| PCA9685_ERR_I2C | 0xFC | PCA9685 I2C communication error |
|
||
|
||
|
||
### SUB CALL and ALL CALL
|
||
|
||
(new since 0.4.0)
|
||
|
||
Please read the datasheet to understand the working of **SUB CALL** and **ALL CALL**.
|
||
|
||
Since version 0.4.0 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 PCA9685 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 PCA9685 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()**
|
||
|
||
|
||
#### OutputEnable
|
||
|
||
Since 0.4.2 (experimental) support to control the OE (Output Enable) pin of the PCA9685.
|
||
This OE pin can control all LEDs simultaneously.
|
||
It also allows to control multiple PCA9685 modules by connecting the OE pins.
|
||
Think of simultaneous switching ON/OFF or get dimming with a high frequency PWM.
|
||
Or use 2 modules alternatively by placing an inverter in between.
|
||
|
||
See datasheet for the details
|
||
|
||
- **bool setOutputEnablePin(uint8_t pin = 255)** sets the IO pin to connect to the OE pin of the PCA9634.
|
||
A value of 255 indicates no pin set/selected.
|
||
Sets the OE pin to HIGH.
|
||
Returns true on success.
|
||
- **bool setOutputEnable(uint8_t value)** Sets the OE pin HIGH or LOW.
|
||
All non zero values are LOW.
|
||
Returns true on success.
|
||
- **uint8_t getOutputEnable()** get the current value of the OE pin.
|
||
If pin is not set/selected it will return HIGH.
|
||
|
||
Note: the OE is LOW active.
|
||
The user has to set the power on value by means of a PULL DOWN resistor.
|
||
|
||
|
||
#### I2C Software reset
|
||
|
||
The goal of this function is to reset ALL PCA9685 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 (See PCA9634).
|
||
|
||
- 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 <20>general<61> method which resets many chips on the I2C-bus.
|
||
However, this method DOES NOT reset the PCA9685 chip.
|
||
Therefore, consult the data sheet of all different chips on the bus to mitigate potential undefined states.
|
||
|
||
When only working with PCA9685 chips on a bus, only method 1 is required.
|
||
|
||
```cpp
|
||
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-PCA9685),
|
||
please give feedback, so the documentation can be improved.
|
||
|
||
For further details of the development, see - #10 (PCA9634 repo)
|
||
|
||
|
||
## Operation
|
||
|
||
See examples
|
||
|
||
|
||
## Future
|
||
|
||
#### Must
|
||
|
||
- improve documentation
|
||
|
||
#### Should
|
||
|
||
- add unit tests (if possible)
|
||
|
||
#### Could
|
||
|
||
- investigate int vs uint16_t ?
|
||
- **setFrequency(), getFrequency(), \_freq**
|
||
- sync with PCA9634/35/85 where possible
|
||
- error handling?
|
||
|
||
#### Wont
|
||
|
||
|
||
## Support
|
||
|
||
If you appreciate my libraries, you can support the development and maintenance.
|
||
Improve the quality of the libraries by providing issues and Pull Requests, or
|
||
donate through PayPal or GitHub sponsors.
|
||
|
||
Thank you,
|
||
|
||
|