j5-delta
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Johnny-Five component for controlling delta robots, based on tapsterbot.
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# J5-Delta
### Delta Robot Component for Johnny-Five
## Usage
```javascript
var five = require("johnny-five");
var Deltabot = require('j5-delta');
var board = new five.Board();
board.on("ready", function() {
var delta = new Deltabot({
pins: [ 9, 10, 11 ],
type: 'tapster'
});
delta.moveTo([20, -20, -150]);
// other commands
});
```
## Constructor Parameters
| Property | Type | Value/Description | Default | Required |
| --- | --- | --- | --- | --- |
| pins | Array | An array of three pins id's with servos attached | | yes |
| startAt | Number | Any number between 0-180. Degrees to initialize the servos at. | 5 | no |
| tapDepth | Number | The depth at which to plunge the end effector for a tap or draw. | -160 | no |
| servoSpeed | Number | Number of seconds it takes your servo to move 60 degrees, used to calculate movement time | 0.40 | no |
| dimensions | Object | Collection of dimensions describing the geometry of the delta robot you want to control. | | no |
| type | String | The name of a known delta robot configuration. If you don't specify this, you should specify *dimensions*. Valid values: 'tapster', 'junky'
## Dimensions
| Variable | Description |
| --- | --- | --- |
| f | base length |
| e | end effector length |
| rf | bicep length |
| re | forearm length |
If you have a custom delta robot you will need to make a few measurements of the geometry and pass it in. Normally, these measurements should be in millimeters. If your design is open source or commonly available, please consider sending a pull request to add it as a named configuration to `configurations.js`!
Example initializing with custom dimensions:
```javascript
var delta = new Deltabot({
pins: [ 9, 10, 11 ],
dimensions: {
f: 163,
e: 80.25,
rf: 128.75,
re: 155
}
});
```
## API
### home()
Move all of the servos to their home position as specififed by `startAt` at Deltabot initialization.
```javascript
deltabot.home();
```
### moveTo(coords, [callback])
Move the end effector to the specified X, Y and Z coordinates. Callback is triggered when the movement is done.
```javascript
deltabot.moveTo([20, -20, -140]);
```
**Note on coordinate system:** The coordinate system origin (0,0,0) starts a point directly centered between the three motor axes. Therefore, the Z coordinate of the end effector will always be below that and negative.
### getPosition([angles])
Get the current position of the end effector through a forward kinematic calculation. If you do not specify the angles, it will use the last known servo angles.
Note: The position returned by `getPosition()` will most likely differ from what you passed in to `moveTo()`. This is due to the limited range of motion on a hobby servo. The position returned by `getPosition()` is closer to the true position.
```javascript
deltabot.moveTo([20, -20, -140]);
deltabot.getPosition(); // [ 0, 19.61168100866987, -20.1826220029087, -140.14643590955427 ]
```
### getServoAngles()
Get the current positions of each of the three servo motors in degrees.
```javascript
deltabot.moveTo([45, -32, -150]);
deltabot.getServoAngles(); // [ 22, 17, 56 ]
```
### tap(x, y, [callback])
Tap at the specified X and Y coordinates, plunging to a depth specified by the *tapDepth* option.
```javascript
deltabot.tap(40, 75);
```
### draw(coords, [callback])
Draw by dragging the end effector at *tapDepth* between all of the X,Y coordinates in the coords paramter.
```javascript
// Draw a 40mm box starting at position 10,10
deltabot.draw([
[10,10],
[50,10],
[50,50],
[50,10],
[10,10]
]);
```