We live in an age in which robots seem to become competitors. But what if they become personal assistants for everyone?
The basic idea of CaRo is to develop a cost-effective and easy to build robot. It is not a robotic arm that needs a lot of motors and a lot of material for a wide reach of action. CaRo is no bigger than a shoe box and still has a raach of action of several meters. The accuracy and reliability is not very high yet. CaRo is therefore currently regarded as a toy. On my homepage you can see what can become of CaRo.
Step 1: Hardware
- Crickit for Feather
- Adafruit Feather Board 32u4 BLE 3
- servo motors, continuous rotation
- power supply
- 3D printed parts (frame, 3 cable reels, housing)
- screws (diameter 2.5 mm)
- rope, tearproof, 1mm diameter (e.g. Dyneema for kitesurfing)
- 3 wall hooks
CaRo is controlled by the Adafruit Feather microcontroller. It is the same microcontroller as the MovingLight project and has an integrated Bluetooth module.
Crickit is a platform for creative robotics and has a lot of slots and pins for motors, lights, sensors and other parts. The 5V power supply is used for all motors and the feather microcontroller. CaRo needs 3 motors. Due to the fact that Crickit has just 2 DC motor slots, we used Servo motors.
The 3d printed frame holds the Servos and the electronics. But only the used Servos fit into the frame. Check the dimensions. The frame and coils are necessary. The case is not necessary.
Servo motors are often supplied with adapters. The coils can be attached to them. To hang CaRo you need 3 hooks and a thin (diameter 1mm) and tearproof rope.
Attention: Only servo motors with the following dimensions fit into the frame:
This servo motor were used:
Continuous Rotation Servomotor (FeeTech FS5103R) Dimensions: 37mm x 54mm x 20mm / 1.5" x 2.1" x 0.8"
Step 2: Assembly
The assembly is very simple. If not already done the headers have to be soldered to the microcontroller and Crickit platform.
- First screw the servo motors to the frame.
- Then the frame can be screwed to the lower housing.
- Then screw the cable reels onto the servo motors.
- Attach Crickit and Feather.
- Mount the upper housing.
However, it should be mentioned that the housing is not absolutely necessary.
Step 3: Software
The code is written in Arduino and the final file can be downloaded. Three libraries must be installed, which are listed at the beginning of the code. The token from the Blynk app must also be inserted.
Install the Blynk app on your smartphone and log in. Create a new project and give it a name. As Device select Arduino Uno and as Connection Type BLE. Then click on Create Project and you will get a token which you have to insert into the code. Explanations of the code can be found in the annotations inside the code.
To add buttons, tap on the surface and select an object from the widget bar. It needs two joysticks. The first joystick is for forward, backward, left and right. And the second joystick for up and down movement. Joystick 1 runs on the virtual pin V0 and Joystick 2 runs on virtual pin V1. The data to be transferred ranges from 0 to 180.
The BLE button enables a Bluetooth connection to the feather. Select the feather from the list. The app can then be started by pressing the play button.
Step 4: Test Run
Sometimes the servo motors have to be calibrated with a small screw. So that the motors do not move when no signal is sent.
By changing the code, the movement of the motors can be changed and optimized.
It is possible to mount adapters on the bottom side.
Step 5: Files
Get the 3D files for printing and the Arduino code.