MicroBlocks

MicroBlocks is a blocks language (like Scratch) that makes it easy for beginners (9 years to adults) to program DUELink boards. A huge benefit of MicroBlocks is that it is live and interactive: users can click commands to see what they do and they can test their scripts as they work.

Yet in spite of its apparent simplicity, MicroBlocks is a fast, powerful programming language with the ability to interface with peripherals via GPIO, I2C, SPI, and serial and nearly 200 extension libraries. In fact, some hardware designers prefer MicroBlocks for rapid prototyping and testing because of its fast, interactive development cycle.

There are two ways to use MicroBlocks with DUELink:

1. Run MicroBlocks directly on DUELink modules/boards Standalone.
2. Use MicroBlocks to control Tethered Modules.

tip

Most product pages include Tethered and Standalone sample projects.

An example of Standalone is when loading and running MicroBlocks directly on boards like DueSTEM or Ghizzy.

A tethered example can be micro:bit that is controlling LED RGB3. The LinkBit adaptor is here to give micro:bit the needed Downlink interface.

It is also possible to combine both options! In this case, MicroBlocks will run Standalone on a DUELink board, that is also Tethered to one, or more, DUELink modules. This can for example be CincoBit running MicroBlocks firmware and user blocks Standalone that is controlling LED RGB3 module.

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MicroBlocks Standalone

While you can load MicroBlocks to make any DUELink module run Standalone, the ones recommended on the educators page make it especially easy to get started.

Installing the Firmware

Educational-tailored boards automatically ship with MicroBlocks preloaded. You can skip this section in most cases. However, everything you need for loading MicroBlocks firmware is on loader.duelink.com/microblocks.

tip

You don't need to install MicroBlocks firmware every time you use MicroBlocks, only if you want to update to a newer version or switch between MicroBlocks and DUELink firmware.

Connecting the Board

You can run MicroBlocks in a Chrome or Edge browser by visiting microblocks.fun and clicking the Run button in the top bar menu or by clicking this link.

You can also download a stand-alone app for Windows, macOS, or Linux from the MicroBlocks Download page.

The first step is to connect to the board.

note

Linux may require an extra step to ensure that the user has access to USB serial devices. See the Linux tab in the Computer Setup section of the MicroBlocks Get Started page.

Click the Connect button in the MicroBlocks editor:

Select Connect (USB) from the menu:

Select the DUELink MicroBlocks board in the dialog that appears, then click the Connect button:

If you do not see your DUELink MicroBlocks board, make sure it is connected with a good USB cable, then click its reset button.

When the board is connected, the Connect button will turn green and the name of the board will appear next to it:

With the board connected, click the file icon and select New from the menu:

MicroBlocks will load a set of libraries that can be used with that board:

To verify that everything is working, click on the set user LED block in the Output category:

On most DUELink boards, this will turn on the green STAT LED. On the CincoBit, which does not have a STAT LED, it will turn on the middle LED in the 5x5 LED display.

Coding in MicroBlocks

MicroBlocks is a live coding environment so you can test as you code and try out blocks to discover what they do.

Click on a block or script to run it:

Drag blocks into the scripting pane and assemble them to create scripts.

Your code is stored in persistent flash memory and can run even when the board is not connected to the MicroBlocks editor.

Scripts starting with a when started block will run when the board is powered on.

MicroBlocks supports concurrency. Up to ten scripts can run at the same time.

Examples

Here is a simple script for the CincoBit:

Here is a similar script using the ClipIt's A touch pad:

These scripts will switch from a "smile" to a "frown" on the CincoBit based on the pressed button.

This script displays the light level as a bar graph on the PixoBit and DueSTEM. It also shows the temperature on the DueSTEM:

In addition to its many built-in blocks, MicroBlocks has nearly 200 libraries that support additional features and peripherals. Click the Add Library button to add libraries.

MicroBlocks Pin Numbers

On the CincoBit and PixoBit, MicroBlocks uses the same edge connector pin numbers as the micro:bit. Pins 0, 1, and 2 are the three alligator clip connections with holes on the left side of the edge connector.

On the CincoBit:

• pin 9 is the analog light sensor
• pin 21 is the buzzer

On the PixoBit:

• pin 21 is the buzzer
• pin 22 is the display reset pin
• pin 23 is the analog light sensor

On all other DUELink boards, MicroBlocks uses standard DUELink pin numbers. Pins 0-9 and 17 are capable of analog input. The pin numbers are marked on the DueSTEM and most other microcomputer boards. You can always find the pin numbers for a given board on its schematic.

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Tethering Modules

MicroBlocks can be running on any board, that then control other DUELink modules. For example, MicroBlocks can be running on a micro:bit that is connected to LED RGB3 module. LinkBit adapter is needed since micro:bit does not have a JST connector.

Another example is with MicroBlocks running on PixoBit that is connected to a few modules.

In either case, the first module is the only one running MicroBlocks. The other tethered modules would be running DUELink official firmware, which is listening to commands coming from MicroBlocks.

Connections

If you are running MicroBlocks on a DUELink board/module, connect the Downlink (D) connector on that board...

...to the Uplink (U) connector of the next DUELink module.

Modules can optionally mounted on a Holey Board.

If you are running MicroBlocks on a non-DUELink board, connect the Daisylink module chain to your board's I2C or UART pins. For example, if you have a micro:bit, you can use a LinkBit.

When using multiple DUELink modules, modules are daisy-chained together by connecting the Downlink (D) connector of one module to the Uplink (U) connector of the next (see Daisylink).

tip

Always connect a Downlink (D) connector to an Uplink (U) connector. Nothing will work if a D is connected to a D or a U to a U anywhere in the chain.

Disconnect USB/power before connecting or disconnecting modules. No worries, as not doing so will not cause any damage to the modules. This is only because DUELink Daisylink is a smart but that resolves module addressing automatically but it only does it on power up.

Daisylink Library

We maintain a set of libraries to simplify the use of MicroBlocks with DUELink. DUELink Daisylink is one of these libraries and it is used to access and control Tethered modules, which can be one module or a Daisylink of modules. In either case, we need this DUELink Daisylink library.

In the MicroBlocks editor, click the Add Library button:

then from Libraries select Kits and Boards and then DUELink Daisylink library:

In this example setup, CincoBit is the board running Standalone and MicroBlocks is loaded and is running on it. The tethered LED RGB3 is is running the official DUELink firmware and is controlled by commands coming from CinoBit.

From the DUELink Daisylink library palette click on the connected? block to verify that your LED RGB3 is connected and detected by CincoBit:

tip

Modules can't be connected/disconnected live. If you don't get a positive response, check your wiring and power cycle the entire chian by unplugging and re-plugging the USB cable..

In this Daisylink example, there is only one device, which is LED RGB3, and it is address 1. If you have another module connected downlink to LED RGB3 it will become device address 2. You can use select device block to select the desired device, and then use the connected? block again to verify that the selected device is functional.

tip

Device address 1 is automatically selected on power up. If you only need to use device address 1, there will be no need to use the select device block.

Module Drivers

Modules drivers come in handy when they are tethered. For example, LED RGB3 ship preloaded with DUELink official firmware and Driver Script. The driver gives you a set of functions that you can access externally, without needing to understand how the module works nor needing to look at schematics. Those functions are documented under the individual product pages, under the Driver tab.

In this case, LED RGB3 includes SetLed(i, c) function, which sets an LED at i index (0 to 2) to c a hexadecimal RRGGBB color (e.g. FF0000 is red).

The DUELink Daisylink library includes helper blocks to build these function. Here is an example of a helper block set RGB3 led that takes the 2 needed argument, the LED index and its color.

tip

The Tethered Samples MicroBlock Project found on individual product pages include examples on how to utilize that module's specific driver. In some cases, the wrappers are in a separate library that can be extracted.

Daisylink Example

This script will sequence through the RGB3 module's LEDs with different colors when the A button is pressed:

The results will look like this:

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MicroBlocks Everywhere!

We recommend starting with MicroBlocks on the boards recommended for educators. From there, all other modules can be daisylinked as shown in the previous section. However, it is possible to run MicroBlocks on any DUELink module, allowing it to run Standalone! For example, you can install MicroBlocks on the LED RGB3 and control the LEDs directly from MicroBlocks.

Since LED RGB3 does not have a USB connector, you will need an adapter such as USB Hook.

Just like before, to install MicroBlocks firmware on a board, you need to set the board in DFU mode. You can do so using the Erase All feature explained earlier. The other option was to force DFU mode using the LDR button. These boards do not have an LDR button but you can accomplish the same results by inserting a small metal paper clip (or a wire) between 2 special small pads, while powering up the board. See the Loader page for full details.

Please note, once once you have MicroBlocks firmware installed on the RGB3 module, you no longer have the DUELink firmware and module Driver Script. Controlling the module's hardware must be done 100% with MicroBlocks code. For modules with simple hardware such as LEDs, buttons, and analog sensors, the MicroBlocks code is easy to write. However, more complex modules such as displays and SD card readers are best used as Daisylinked modules so one can take advantage of the hardware support built into the DUELink standard firmware. For example, instead of loading MicroBlocks directly on the SD Card module and worrying about file system and SD drivers, use MicroBlocks firmware on CincoBit, which is then connected to the SD Card module that is running the DUELink standard firmware and Driver Script.

Additional Libraries

When connected to one of the educational boards, MicroBlocks adds the relevant libraries automatically. For example, when a new project is created while connected to a CincoBit board, MicroBlocks adds the LED Display library.

Beyond what is already included in MicroBlocks editor, we also provide additional MicroBlocks libraries. Download the library you need from the Downloads page and add it to your MicroBlocks project by using the Add Library button or by dropping the library file onto the MicroBlocks editor.

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Linux Support

Linux may require an extra step to ensure that the user has access to USB serial devices. See the Linux tab in the Computer Setup section on MicroBlocks Get Started website.

Linux users are expected to know how to set permissions but here is an example script to get you started.

#!/bin/bash

echo "Adding user to dialout group for serial port access..."
sudo usermod -aG dialout $USER

# Check if user was added to dialout group
if id -nG "$USER" | grep -qw "dialout"; then
    echo "User $USER added to dialout group successfully."
else
    echo "Failed to add user to dialout group. Please check permissions."
    exit 1
fi

echo "Creating udev rule for STM32 DFU mode..."

# Add the udev rule for STM32 DFU mode (Vendor ID: 0483, Product ID: df11)
echo 'SUBSYSTEM=="usb", ATTR{idVendor}=="0483", ATTR{idProduct}=="df11", MODE="0666"' | sudo tee /etc/udev/rules.d/99-stm32-dfu.rules > /dev/null

# Reload udev rules to apply the changes
sudo udevadm control --reload-rules

echo "Permissions set successfully!"
echo "For changes to take effect:"
echo "- You need to log out and log back in for the group changes (serial port access) to take effect."
echo "- After logging in again, you should have access to both serial and DFU mode without requiring sudo."

echo "If you are unsure about how to log out, please simply restart your system."

Save the above script into a .sh file and give it executable permissions (chmod +x). Now, you can run the .sh file and then reboot (or re-login), for the system to take effect.

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MicroBlocks Resources

These are some useful resources:

• MicroBlocks Main Website
• User Guide
• Blocks Reference
• Libraries Reference
• Learning Guides