73 lines
1.8 KiB
Markdown
73 lines
1.8 KiB
Markdown
# Sigma-delta Module
|
|
| Since | Origin / Contributor | Maintainer | Source |
|
|
| :----- | :-------------------- | :---------- | :------ |
|
|
| 2017-01-13 | [Arnim Läuger](https://github.com/devsaurus) | [Arnim Läuger](https://github.com/devsaurus) | [sigma_delta.c](../../../app/modules/sigma_delta.c)|
|
|
|
|
This module provides access to the [sigma-delta](https://en.wikipedia.org/wiki/Delta-sigma_modulation) component. It's a hardware signal generator that can be routed to any of the output GPIOs.
|
|
|
|
The signal generation is controlled by the [`setprescale()`](#sigma_deltasetprescale) and [`setduty()`](#sigma_deltasetduty) functions.
|
|
|
|
## sigma_delta.close()
|
|
Reenables GPIO functionality at the related pin.
|
|
|
|
#### Syntax
|
|
`sigma_delta.close(channel)`
|
|
|
|
#### Parameters
|
|
- `channel` 0~7, sigma-delta channel index
|
|
|
|
#### Returns
|
|
`nil`
|
|
|
|
## sigma_delta.setprescale()
|
|
Sets the prescale value.
|
|
|
|
#### Syntax
|
|
`sigma_delta.setprescale(channel, value)
|
|
|
|
#### Parameters
|
|
- `channel` 0~7, sigma-delta channel index
|
|
- `value` prescale 1 to 255
|
|
|
|
#### Returns
|
|
`nil`
|
|
|
|
#### See also
|
|
[`sigma_delta.setduty()`](#sigma_deltasetduty)
|
|
|
|
## sigma_delta.setduty()
|
|
Sets the duty value.
|
|
|
|
#### Syntax
|
|
`sigma_delta.setduty(channel, value)`
|
|
|
|
#### Parameters
|
|
- `channel` 0~7, sigma-delta channel index
|
|
- `value` duty -128 to 127
|
|
|
|
#### Returns
|
|
`nil`
|
|
|
|
#### See also
|
|
[`sigma_delta.setprescale()`](#sigma_deltasetprescale)
|
|
|
|
## sigma_delta.setup()
|
|
Routes the sigma-delta channel to the specified pin. Target prescale and duty values should be applied prior to enabling the output with this command.
|
|
|
|
#### Syntax
|
|
`sigma_delta.setup(channel, pin)`
|
|
|
|
#### Parameters
|
|
- `channel` 0~7, sigma-delta channel index
|
|
- `pin` 0~33, IO index
|
|
|
|
#### Returns
|
|
`nil`
|
|
|
|
#### Example
|
|
```lua
|
|
sigma_delta.setprescale(0, 128)
|
|
sigma_delta.setduty(0, 0)
|
|
sigma_delta.setup(0, 4)
|
|
```
|