145 lines
5.1 KiB
Markdown
145 lines
5.1 KiB
Markdown
|
# Equipping a microservo with Crocodile clips
|
||
|
|
|
||
|
|
## ~ hint
|
||
|
|
|
||
|
|
If you are conducting a class or group activity, you should consider preparing all servos ahead of time.
|
||
|
|
|
||
|
|
## ~
|
||
|
|
|
||
|
|
## Using a microservo with the @boardname@
|
||
|
|
|
||
|
|
The @boardname@ provides just enough current to operate the SG90 microservo. This servo requires 3 connections: **GND**, **3V** and a logic **pin**. In this tutorial, we will equip the servo with crocodile clips to make it easier to use. However, you could also use a shield or crocodile clips with a male connector on one end to achieve the same result.
|
||
|
|
|
||
|
|
### ~ hint
|
||
|
|
|
||
|
|
To better understand how servos work and how they are controlled, take a few minutes to read this [Brief Guide to Servos](https://www.kitronik.co.uk/pdf/a-brief-guide-to-servos.pdf).
|
||
|
|
|
||
|
|
### ~
|
||
|
|
|
||
|
|
## The easy way: Alligator/Crocodile Clip to Male Jumpers #hintconnection
|
||
|
|
|
||
|
|
The easiest way to connect a servo to the @boardname@ is to use cables with an **Alligator/Crocodile clip** on one end
|
||
|
|
and a **Male jumper (pig tail)** on the other end. You can purchase bundles these cables from various electronic resellers or easily build some as shown here.
|
||
|
|
|
||
|
|
https://youtu.be/XtzsydSTXEg
|
||
|
|
|
||
|
|
### Materials
|
||
|
|
|
||
|
|
* 1 Crocodile clip cable
|
||
|
|
* 1 male (pig tail) cable
|
||
|
|
* Cutting pliers or wire cutter
|
||
|
|
* 1 piece of heat shrink tubing and a lighter
|
||
|
|
|
||
|
|
Simply cut the cables, strip them, twist the bare wires together, and cover the connection with some heat shrink tubing.
|
||
|
|
|
||
|
|
### ~ hint
|
||
|
|
|
||
|
|
It is very **important** to ensure a good connection between the 2 cables. If the connection is weak, the microservo will not receive enough current and it will not work. **If you have access to a soldering iron, we strongly recommend that you solder this connection.**
|
||
|
|
|
||
|
|
### ~
|
||
|
|
|
||
|
|
## Direct connection
|
||
|
|
|
||
|
|
You can also connect your crocodile clips directly to the servo.
|
||
|
|
|
||
|
|
### Materials
|
||
|
|
|
||
|
|
* Cutting pliers or wire cutter
|
||
|
|
* Tape (masking, duct tape, and/or packing tape)
|
||
|
|
* 3 crocodile clips, yellow, red and black.
|
||
|
|
* 1 micro servo 9g (SG90)
|
||
|
|
|
||
|
|
### Step 1: Cut off the connector
|
||
|
|
|
||
|
|
With the cutting pliers, cut off the dark plastic connector.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 2: Strip the ends of the cables
|
||
|
|
|
||
|
|
Using the pliers or a wire stripper, strip the plastic insulation from the cables.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 3: Twist the wire strands together
|
||
|
|
|
||
|
|
Twist the strands of bare wire at the ends of the servo cables together.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 4: Crocodile clip
|
||
|
|
|
||
|
|
Cut a crocodile cable in two and strip off the insulation. If it's possible, try to use cables with colors that match the cables on the servo!
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 5: Thread the cable ends together
|
||
|
|
|
||
|
|
Place the cables next to each other...
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
... and thread them together.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### ~ hint
|
||
|
|
|
||
|
|
It is very **important** to ensure that there is a good connection between the 2 cables. If the connection is weak, the microservo will not receive enough current and it will not work. **If you have access to a soldering iron, we strongly recommend soldering this connection.**
|
||
|
|
|
||
|
|
### ~
|
||
|
|
|
||
|
|
### Step 6: Protect the connection
|
||
|
|
|
||
|
|
Protect the connection with heat shrink tubing, electrical tape, or duct tape.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 7: Repeat for all cables
|
||
|
|
|
||
|
|
Repeat the same process until all cables are connected.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
### Step 8: Testing!
|
||
|
|
|
||
|
|
It's time to test and find out if your connections are all secure and that the servo will function **when the @boardname@ is powered by battery**.
|
||
|
|
|
||
|
|
* Connect the microservo cables to these pins on the @boardname@: black to **GND**, red to **3V**, and the remaining cable to pin **0**.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
## ~ hint
|
||
|
|
|
||
|
|
When attaching the crocodile clips to the pins, don't be afraid to clamp on to the edge of the board with the clips.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
## ~
|
||
|
|
|
||
|
|
* Download the following code to your @boardname@.
|
||
|
|
|
||
|
|
```blocks
|
||
|
|
basic.forever(() => {
|
||
|
|
pins.servoWritePin(AnalogPin.P0, pins.map(
|
||
|
|
input.acceleration(Dimension.X),
|
||
|
|
-512,
|
||
|
|
512,
|
||
|
|
0,
|
||
|
|
180
|
||
|
|
))
|
||
|
|
})
|
||
|
|
```
|
||
|
|
|
||
|
|
* Test with both power sources and make sure that the servo moves when you tilt the board:
|
||
|
|
>* Connected with USB.
|
||
|
|
>* Powered by batteries **only** and not connected with USB.
|
||
|
|
|
||
|
|
## Calibrating
|
||
|
|
|
||
|
|
Use the [servo calibrator](/projects/servo-calibrator) program to determine the best angles to use for your make.
|
||
|
|
|
||
|
|
## Troubleshooting
|
||
|
|
|
||
|
|
If your servo seems to stutter and remain stuck at a particular position, it means that it's not receiving enough power. This is probably due to a weak connection or low battery level. Make sure that each connection is good and check your batteries.
|