Overview

The four motor was prototyped with a protoboard pCB and a PCA9685 as a PWM expander. Now it is hand solderable featuring the TLC5940 and 2 L293D H-Bridges. 4 H-bridges are driven by 8 outputs of a PCA9685. The PCA talks to the client via I2C.

The used the four motor kit to build a mecanum car. The car moves forwards and backwards, and turns like a tank by applying power to only one side. In regards to circuitry, the Mecanum car is a bit more complicated than our other projects, however it is a great project to pursue if you would like to learn more about how to properly drive and control motors with our platform.

Add Image, Fritzing or animated gif here

Things used in this project

Hardware components

Tools Used

Story

The Idea

The Quantum revision on the Four Motor kit was built to familiarize our users with using PWM expander chips and H-bridges with our platform with a fun and approachable project.

Video

Build Process

Step 1: PCB Assembly and Soldering

Download the Four Motor DIY Kit Bill of Materials:

Gather your Four Motor Kit PCB and all required components listed in the BOM.

It is especially important to follow the BOM exactingly as it tells you where to place the components on the PCB. The fifth column on the BOM is the “parts” column. This column designates which position on the PCB you are to pace the component. For example, if under the parts column you have a resistor labeled r1 you would then find the position marked r1 on the PCB and place the resistor there.

Using some form of work holder is advised. You can find a list of suitable work holders on our Recommended Tools List.

Step 2: Connecting the Motors to the board

Here you can see the junctions labeled M1 → M4. These are the terminals to which you will connect your motor leads.

The junctions are paired together as follows: (M1,M3) and (M2,M4). It is important that for each of these pairs you match which leads from the motors go into the terminals labeled X and Y. If you don’t, the directions from your motors will be out of sync. In the table below I will show you how we wired our motors to the terminals.

With your terminal orientation settled, you can then attach your motors to the mecanum frame. With our Mecanum Kit, the each motor is attached via 2 Allen Screws as seen here:

Take care to ensure that your paired motors (M1,M3) are on one side, and (M2,M4) are on the other. If you don’t your motor directions will be out of sync.

Step 3: Wiring your Four Motor to the Builder Base

Once all of your motors are wired and mounted you can connect your PCB to the Builder Base. You can follow along to the diagram and table below to ensure you have the appropriate wiring.

Step 4: Build the Firmware

Navigate to the Firmware Builder and create a new Firmware file. We named ours Mecanum Kit.

Next, click the “+ Add Hardware” button and find the Motor device via the search bar, select it, name it, and then click “Add Hardware”. We named ours Motor FL.

Now, repeat these steps three more times, naming the Motors Motor FR, Motor RR, and Motor RL.

You should now have four motor devices in your firmware file.

To configure the drivers for the Motor FL device, select the TLC5940 Driver from the driver dropdown menu.

Now, set the pins accordingly:

Repeat these steps for the three remaining motors. You can find the proper pin configurations in the table below.

You have now finished configuring your firmware, so save your firmware by clicking the “Save button at the bottom of the screen.

Now you can upload your firmware to the client you have attached to the Mecanum car.

Step 5: Build the Application

Navigate to the Applications page and click the “+ Create New Button”, name your application, and click create.

You will now be directed to the App Builder Canvas.

Using the search bar in the left hand tool-bar search for the Motor code object and drag four of them onto the canvas.

Name the Motor Objects as we do, this will help you to identify the motors during the application mapping. To rename them, click on the motor object and change the name in the properties panel on the right.

In order to save the names you must click the “save properties” button at the bottom of the properties tab.

Next, search for the “Manual Ranging” code object using the search bar and drag two of them onto the canvas.

Configure each manual Ranging object as follows:

Next, connect each of the Value out ports from the Manual ranging objects to the Motor objects as follows:

Now search for the “Joystick” object and drag two of them onto the canvas. Name one Joystick Left, and the other Joystick Right.

Now connect the Y-Axis ports from the Joystick objects to the Manual Ranging objects as follows:

Now, in this state your Mecanum Kit App will work with a joystick, but we are going to finish the App by also making it steerable using the dashboard interface.

Find the Digital Toggle Code object, drag three of them onto the screen, and name them.

Connect the Digital Toggle objects to the manual ranging objects as follows:

Now, we just need to add buttons, so search for them and add three of them to your application.

Connect the Button objects to the Digital Toggle objects as follows:

Congrats, your app is now complete!

Hit “Save App” and go back to your applications page.

Step 6: Map Your Application

You should now be back on the Apps page.

Find your “Mecanum KIT” app and hit the play button.

A list containing all of the devices in your application will expand.

Next click on the “Motor RL” device and the client dropdown menu will appear on the right.

Select the Motor RL driver from the dropdown menu and hit “Done”.

Repeat the same steps for the Motor FL,RR, and RL devices, ensuring that you match the device name to the object name.

Now, you can map the Joystick Devices in the same way, but make sure that you match the Left and Right Joystick drivers with the Left and Right Joystick devices.

If you have yet to build a Joystick project you can find out how to build one here:

Joystick DIY Kit

Notice how the status symbols have changed to green checkmarks.

Step 7: Run the Application!

Next, hit “Save + Run”

Congratulations! Your Mecanum project is now complete, have fun!

Code

Gallery

Resources