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| -rw-r--r-- | docs/feature_debounce_type.md | 64 |
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diff --git a/docs/feature_debounce_type.md b/docs/feature_debounce_type.md index 8012037b6f..807b902a6c 100644 --- a/docs/feature_debounce_type.md +++ b/docs/feature_debounce_type.md @@ -57,70 +57,78 @@ susceptible to noise, you must choose a debounce method that will also mitigate if the scanning is slow, and you are using a timestamp-based algorithm, you might end up making a debouncing decision based on only two sampled values, which will limit the noise-resistance of the algorithm. * Currently all built-in debounce algorithms support timestamp-based debouncing only. In the future we might - implement cycles-based debouncing, and it will be selectable via a ```config.h``` macro. + implement cycles-based debouncing, and it will be selectable via a `config.h` macro. 2) Symmetric vs Asymmetric * Symmetric - apply the same debouncing algorithm, to both key-up and key-down events. - * Recommended naming convention: ```sym_*``` + * Recommended naming convention: `sym_*` * Asymmetric - apply different debouncing algorithms to key-down and key-up events. E.g. Eager key-down, Defer key-up. - * Recommended naming convention: ```asym_*``` followed by details of the type of algorithm in use, in order, for key-down and then key-up + * Recommended naming convention: `asym_*` followed by details of the type of algorithm in use, in order, for key-down and then key-up 3) Eager vs Defer * Eager - any key change is reported immediately. All further inputs for DEBOUNCE ms are ignored. * Eager algorithms are not noise-resistant. * Recommended naming conventions: - * ```sym_eager_*``` - * ```asym_eager_*_*```: key-down is using eager algorithm - * ```asym_*_eager_*```: key-up is using eager algorithm + * `sym_eager_*` + * `asym_eager_*_*`: key-down is using eager algorithm + * `asym_*_eager_*`: key-up is using eager algorithm * Defer - wait for no changes for DEBOUNCE ms before reporting change. * Defer algorithms are noise-resistant * Recommended naming conventions: - * ```sym_defer_*``` - * ```asym_defer_*_*```: key-down is using defer algorithm - * ```asym_*_defer_*```: key-up is using defer algorithm + * `sym_defer_*` + * `asym_defer_*_*`: key-down is using defer algorithm + * `asym_*_defer_*`: key-up is using defer algorithm 4) Global vs Per-Key vs Per-Row * Global - one timer for all keys. Any key change state affects global timer - * Recommended naming convention: ```*_g``` + * Recommended naming convention: `*_g` * Per-key - one timer per key - * Recommended naming convention: ```*_pk``` + * Recommended naming convention: `*_pk` * Per-row - one timer per row - * Recommended naming convention: ```*_pr``` + * Recommended naming convention: `*_pr` * Per-key and per-row algorithms consume more resources (in terms of performance, and ram usage), but fast typists might prefer them over global. ## Supported Debounce Algorithms -QMK supports multiple debounce algorithms through its debounce API. +QMK supports multiple algorithms through its debounce API. -### Debounce selection +### Debounce Time -Keyboards may select one of the core debounce methods by adding the following line into ```rules.mk```: +Default debounce time is 5 milliseconds and it can be changed with the following line in `config.h`: +``` +#define DEBOUNCE 10 +``` +?> Setting `DEBOUNCE` to `0` will disable this feature. + +### Debounce Method + +Keyboards may select one of the core debounce methods by adding the following line into `rules.mk`: ``` DEBOUNCE_TYPE = <name of algorithm> ``` Name of algorithm is one of: -| Algorithm | Description | -| ------------------------- | ----------- | -| ```sym_defer_g``` | Debouncing per keyboard. On any state change, a global timer is set. When ```DEBOUNCE``` milliseconds of no changes has occurred, all input changes are pushed. This is the highest performance algorithm with lowest memory usage and is noise-resistant. | -| ```sym_defer_pr``` | Debouncing per row. On any state change, a per-row timer is set. When ```DEBOUNCE``` milliseconds of no changes have occurred on that row, the entire row is pushed. This can improve responsiveness over `sym_defer_g` while being less susceptible to noise than per-key algorithm. | -| ```sym_defer_pk``` | Debouncing per key. On any state change, a per-key timer is set. When ```DEBOUNCE``` milliseconds of no changes have occurred on that key, the key status change is pushed. | -| ```sym_eager_pr``` | Debouncing per row. On any state change, response is immediate, followed by ```DEBOUNCE``` milliseconds of no further input for that row. | -| ```sym_eager_pk``` | Debouncing per key. On any state change, response is immediate, followed by ```DEBOUNCE``` milliseconds of no further input for that key. | -| ```asym_eager_defer_pk``` | Debouncing per key. On a key-down state change, response is immediate, followed by ```DEBOUNCE``` milliseconds of no further input for that key. On a key-up state change, a per-key timer is set. When ```DEBOUNCE``` milliseconds of no changes have occurred on that key, the key-up status change is pushed. | +| Algorithm | Description | +| --------------------- | ----------- | +| `sym_defer_g` | Debouncing per keyboard. On any state change, a global timer is set. When `DEBOUNCE` milliseconds of no changes has occurred, all input changes are pushed. This is the highest performance algorithm with lowest memory usage and is noise-resistant. | +| `sym_defer_pr` | Debouncing per row. On any state change, a per-row timer is set. When `DEBOUNCE` milliseconds of no changes have occurred on that row, the entire row is pushed. This can improve responsiveness over `sym_defer_g` while being less susceptible to noise than per-key algorithm. | +| `sym_defer_pk` | Debouncing per key. On any state change, a per-key timer is set. When `DEBOUNCE` milliseconds of no changes have occurred on that key, the key status change is pushed. | +| `sym_eager_pr` | Debouncing per row. On any state change, response is immediate, followed by `DEBOUNCE` milliseconds of no further input for that row. | +| `sym_eager_pk` | Debouncing per key. On any state change, response is immediate, followed by `DEBOUNCE` milliseconds of no further input for that key. | +| `asym_eager_defer_pk` | Debouncing per key. On a key-down state change, response is immediate, followed by `DEBOUNCE` milliseconds of no further input for that key. On a key-up state change, a per-key timer is set. When `DEBOUNCE` milliseconds of no changes have occurred on that key, the key-up status change is pushed. | -?> ```sym_defer_g``` is the default if ```DEBOUNCE_TYPE``` is undefined +?> `sym_defer_g` is the default if `DEBOUNCE_TYPE` is undefined. -?> ```sym_eager_pr``` is suitable for use in keyboards where refreshing ```NUM_KEYS``` 8-bit counters is computationally expensive or has low scan rate while fingers usually hit one row at a time. This could be appropriate for the ErgoDox models where the matrix is rotated 90°. Hence its "rows" are really columns and each finger only hits a single "row" at a time with normal usage. +?> `sym_eager_pr` is suitable for use in keyboards where refreshing `NUM_KEYS` 8-bit counters is computationally expensive or has low scan rate while fingers usually hit one row at a time. This could be appropriate for the ErgoDox models where the matrix is rotated 90°. Hence its "rows" are really columns and each finger only hits a single "row" at a time with normal usage. ### Implementing your own debouncing code You have the option to implement you own debouncing algorithm with the following steps: -* Set ```DEBOUNCE_TYPE = custom``` in ```rules.mk```. -* Add ```SRC += debounce.c``` in ```rules.mk``` -* Implement your own ```debounce.c```. See ```quantum/debounce``` for examples. +* Set `DEBOUNCE_TYPE = custom` in `rules.mk`. +* Add `SRC += debounce.c` in `rules.mk` +* Implement your own `debounce.c`. See `quantum/debounce` for examples. * Debouncing occurs after every raw matrix scan. * Use num_rows instead of MATRIX_ROWS to support split keyboards correctly. * If your custom algorithm is applicable to other keyboards, please consider making a pull request. |