mirror of
https://github.com/xodio/xod.git
synced 2026-03-15 13:16:53 +01:00
51 lines
1.7 KiB
Markdown
51 lines
1.7 KiB
Markdown
---
|
||
title: Smoother Changes
|
||
---
|
||
|
||
# #20. Smoother Changes
|
||
|
||
<div class="ui segment note">
|
||
<span class="ui ribbon label">Note</span>
|
||
This is a web-version of a tutorial chapter embedded right into the XOD IDE.
|
||
To get a better learning experience we recommend to install the
|
||
<a href="/downloads/">desktop IDE</a> or start the
|
||
<a href="/ide/">browser-based IDE</a>, and you’ll see the same tutorial there.
|
||
</div>
|
||
|
||
In the previous examples our servo turns to the set angle at its maximum speed.
|
||
High speed is not always necessary and can damage the servo itself if the shaft
|
||
hits an obstacle.
|
||
|
||
Let’s improve our patch by making the servo move more smoothly. To achieve
|
||
that, we’ll need to set the `VAL` pin value along with a series of transitional
|
||
values. There’s a node for that, and it's called `fade`.
|
||
|
||
|
||
|
||
The `fade` node is in `xod/core`. This node returns a smooth series of
|
||
transitional values, so it will smoothen our servo motion.
|
||
|
||
* The `TARG` pin waits for a target value.
|
||
* The `RATE` pin is a number that defines amount of change for the transitional
|
||
values per each second.
|
||
|
||
The output pin returns 0 at the start of the program. Then, it starts to move
|
||
toward the `TARG` value by the `RATE` steps. The value of the output pin is
|
||
saved, so if the `TARG` value changes, the output will start to move to this
|
||
value from the last one returned.
|
||
|
||
## Test circuit
|
||
|
||
<div class="ui segment note">
|
||
<span class="ui ribbon label">Note</span>
|
||
The circuit is the same as for the previous lesson.
|
||
</div>
|
||
|
||
|
||
|
||
[↓ Download as a Fritzing project](./circuit.fzz)
|
||
|
||
Now, the servo will turn at a speed of 18° per second (0.1 = 18°).
|
||
|
||
[Next lesson →](../21-pulses/)
|