5.9 KiB
M62429
Arduino library for M62429 volume control IC.
Description
M62429
This library is used to set the attenuation (volume) of the M62429 IC a.k.a. FM62429.
The communication needs a minimum delay of 1.6 microseconds. This is defined in the library in M62429_CLOCK_DELAY == 2 For AVR (UNO, slow device) it is defined as 0, as the digitalWrite takes time enough.
For faster processors this define can be overruled runtime by setting it before including "M62429.h" or by defining it as command line parameter.
M62429_RAW
The library also implements a M62429_RAW class which has a minimalistic interface.
Interface M62429
The interface is straightforward
Use #include "M62429.h"
- void begin(uint8_t dataPin, uint8_t clockPin) defines the clock and data pin. One has to create one object per IC.
- int getVolume(uint8_t channel) channel is 0, 1 or 2 (both). In the latter case the volume of channel 0 is used as volume of both channels. See remark future section.
- int setVolume(uint8_t channel, uint8_t volume)
- channel = 0, 1, 2 = both
- volume = 0 .. 255
- Note: if system is muted, no changes are made.
- int incr(uint8_t channel = 2) increment volume (both channels is default) until max (255) is reached.
This is another way to set volume that is better suited for a rotary
encoder or a [+] button.
- Note: if system is muted, no changes are made.
- int decr(uint8_t channel = 2) decrement volume (both channels is default) until 0 is reached.
- Note: if system is muted, no changes are made.
- int average() averages the 2 channels to same = average level.
Sort of set balance in the middle functionality.- Note: if system is muted, no changes are made.
- void muteOn() silences both channels but remembers the volume. GetVolume() will return the 'saved' volume value.
- void muteOff() resets the volume per channel again.
- bool isMuted() returns the muted state.
Note: the volume goes from 0..255 while the actual steps go from 0..87. Therefore not every step in volume will make a "real" step (roughly 1 in 3). This choice is made as the range 0..255 is more often used than the 0..87 range and therefore better fits other sensors and devices.
Error codes
The functions getVolume(), setVolume(), incr(), decr() and average() can return one of the error codes.
| value | name | notes |
|---|---|---|
| 0 | M62429_OK | no error |
| -1 | M62429_MUTED | system is muted, use muteOff() |
| -10 | M62429_CHANNEL_ERROR | channel must be 0, 1 or 2 |
Operation
See examples
Interface M62429_RAW
The interface is minimalistic. No parameter or other checks are made.
Use #include "M62429.h"
- void begin(uint8_t dataPin, uint8_t clockPin) defines the clock and data pin. One has to create one object per IC.
- int getAttn(uint8_t channel) channel is 0, 1 or 2 (both). In the latter case the attenuation of channel 0 is used as attenuation of both channels.
- void setAttn(uint8_t channel, uint8_t attn)
- channel = 0, 1, 2 = both
- attenuation = 0 .. 87
Future
Mixer
- Control multiple M62429 IC's
- One shared dataPin and clockPin per IC.
- use a PCF8574 / PCF8575 as selector
- would allow for 16 stereo or 32 mono channels. Runtime configuration mono / stereo would be cool.
PCF8574 or PCF8575 is used as device selector
AND port takes DATA and CLOCK to right M62429
identical schema for all 8/16 ports
PCF8575 AND M62429
+---------+ +---+ +---------+
| |=======+======| & |==========| data |
| | +===|======| | | |
- I2C - | | | | +---+ | |
| | | | | |
| | | | +---+ | |
| | | +======| & |==========| clock |
| | | +====| | | |
| | | | +---+ | |
+---------+ | | +---------+
| |
DATA ==============+ |
CLOCK ====================+
Volume pan model
- model with one volume(0..100%) and one balance(-100..100) == pan().
- Also a left() and right() incremental balance might be added.
Does this model work better than 2 separate volume channels?
Other
- separate releaseNotes.md?
- change getVolume(both) to return max of the two channels? would be better.
- min() to reduce volume to minimum of both channels.
- create setAttn(channel, attn) and getAttn() for low level control.
- needs cached attn values.
wont
- muteOff() should increase gradually. takes too much blocking time.
- Mute() could be per channel, default = both / all. would add a lot of extra testing. the user can implement a setVOlume(chan, 0)
- mute50() reduces levels with 50% (rounded down?). user can implement this setVolume(chan, getVolume(chan)/2);