5.4 KiB
M5ROTATE8
Arduino library for M5 8ROTATE 8x rotary encoders.
Description
Experimental
M5ROTATE8 is an Arduino class to read the 8 rotary encoders of the M5 8ENCODER module. It also provides means to write RGB values to the 8 LED's in the same module.
The rotary encoders can be read as an absolute counter (since start or reset) or as an relative counter (since last time read). The value can be both positive and negative depending on the direction of turns. The absolute counters can be given an initial value. The counters can be reset per channel. The library can also read the key pressed status of every rotary encoder.
The library can read the state of the mini switch.
The library can set the RGB value of the 9 LEDS. The RotaryEncoder module has no brightness, like the 8ANGLe unit does.
First tests with hardware have been done. Warning: One strange observation, the RE makes steps of size 2 and occasionally step size 1. This needs further investigation, so use with care.
Missing in the device is an interrupt signal e.g. on change. One has to poll all channels for changes which is not efficient. A single byte register that showed change since last read would allow to monitor all 8 rotary encoders in one call.
Feedback is welcome!
I2C
The address range is in theory from 0..127, however the I2C specification states it should be between 8 and 119 as some addresses are reserved. The default address is 0x41 or 65.
| clock | works | notes |
|---|---|---|
| 100 KHz | yes | |
| 200 KHz | yes | |
| 400 KHz | yes | max speed advised. |
| 600 KHz | no |
See log file performance sketch.
Accuracy
The overall behaviour looks not too bad, there are 30 steps per rotation. The rotary encoders show a step size of 2 and sometimes a step size of 1. So normally one rotation gives +60 or -60. The step size needs investigation as I would expect step size 1, always.
Related
Interface
#include "M5ROTATE8.h"
Constructor part
- M5ROTATE8(uint8_t address = M5ROTATE8_DEFAULT_ADDRESS, TwoWire *wire = &Wire) constructor. Default address = 0x41, default Wire.
- bool begin(int sda, int scl) ESP32 et al.
- bool begin() initialize I2C, checks if connected.
- bool isConnected() checks if address is on the I2C bus.
- bool setAddress(uint8_t address = M5ROTATE8_DEFAULT_ADDRESS) set a new address for the device. Default address = 0x41.
- uint8_t getAddress() convenience function.
- uint8_t getVersion() get firmware version from device.
Rotary encoder part
- int32_t getAbsCounter(uint8_t channel) Read a absolute position of the rotary encoder since reset or start.
- **void setAbsCounter(uint8_t channel, int32_t value);
- int32_t getRelCounter(uint8_t channel) Read a relative position of the rotary encoder since reset. Note: this counter will reset after each read.
- bool getKeyPressed(uint8_t channel) get key status of the rotary encoder. True is pressed.
- bool resetCounter(uint8_t channel) reset a rotary encoder.
- void resetAll() reset all counters to 0.
Input switch part
- uint8_t inputSwitch() read status of the switch.
LED part
- bool writeRGB(uint8_t channel, uint8_t R, uint8_t G, uint8_t B) Set the RGB value of a specific LED.
channel = 0..8 - bool setAll(uint8_t R, uint8_t G, uint8_t B) set all LEDs.
- bool allOff() switches all LEDs off.
Future
Must
- improve documentation
- keep in sync with M5ANGLE8 where possible.
- investigate step size 2 / 1.
- An easy patch: divide by 2 resulting in step size 1 or 0
Should
- error handling
- optimize low level calls
- merge into two functions => read/write array + length.
- resetAll() could be "one call"
- bool readRGB(channel, &R, &G, &B)
- or uint32_t readRGB(uint8_t channel)
- improve on return values of functions.
- improve performance
- investigate address changes
Could
- add examples
- digital lock
- add unit tests
Wont (unless)
Support
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Thank you,