pxt-calliope/docs/device/usb.md

Running programs on your micro:bit

How to compile, transfer, and run a program on your micro:bit.

While you're writing and testing your programs, you'll mostly be running them in the simulator, but once you've finished your program you can compile it and run it on your micro:bit.

The basic steps are:

1. Connect your micro:bit to your computer via USB
2. Click Download and download the .hex file
3. Copy the .hex file from your computer onto the micro:bit drive

Requirements

You need the following things to transfer and run a script on your micro:bit:

• A-Male to Micro USB cable to connect your computer to your micro:bit. This is the same cable that is commonly used to connect a smart phone to a computer.
• A PC running Windows 7 or later, or a Mac running OS X 10.6 or later

Step 1: Connect your micro:bit to your computer

First, connect the micro:bit:

1. Connect the small end of the USB cable to the micro USB port on your micro:bit.

2. Connect the other end of the USB cable to a USB port on your computer.

Your computer should recognise your micro:bit as a new drive. On computers running Windows, MICROBIT appears as a drive under Devices and drives. On a Mac it appears as a new drive under Devices.

Windows

Mac

Step 2: Download your program

1. Open your project on codethemicrobit.com
2. Click Download
3. When prompted, choose to save the compiled file onto your computer. The prompt will be different depending on which browser you are using, or whether you are using a Windows computer or a Mac

Windows

Chrome

Your .hex file appears as a download at the bottom of the browser. Click on the arrow next to the name of the file and then click Show in folder.

Drag and drop the .hex file from the download folder onto the MICROBIT drive.

Firefox

A window will appear asking whether you want to save or open the .hex file. Select Save File and then select OK.

The file will then appear in your downloads in the top right of your browser. Click the folder icon next to the filename to open it in Windows Explorer.

Drag and drop the .hex file from the download folder onto the MICROBIT drive.

Microsoft Edge

A message will appear at the bottom of the browser asking what you want to do with the file. Click Save:

Then click Open folder and drag and drop the file from your Downloads to your MICROBIT drive.

Internet Explorer

A message will appear at the bottom of the browser asking what you want to do with the file. Click Save:

Then click Open folder and drag and drop the file from your Downloads to your MICROBIT drive.

Mac

Safari

When you select Download in Safari a file called Unknown will be downloaded into your Downloads folder. Open your Downloads folder and drag and drop the file onto your MICROBIT drive, under Devices:

Firefox

A dialogue box will appear, asking whether you would like to open or save your hex file. Select Save file and click OK and the file will then appear in your downloads in the top right of your browser. Right click on the file and click on Show in Finder and the file will appear in your downloads folder. Select the file and drag and drop it onto your MICROBIT drive.

Chrome

When you select Download in Chrome, the file will appear at the bottom of the browser. Click on the small arrow and select Show in Finder. This will show the file in your download folder. Drag and drop the file onto your MICROBIT drive.

Step 3: Transfer the file to your micro:bit

• Once you've found the folder containing your .hex file, drag and drop it onto your MICROBIT drive
• If you're using Windows, you can use Send to as described below
• The LED on the back of your micro:bit flashes during the transfer (which should only take a few seconds).
• Once transferred, the code will run automatically on your micro:bit. To rerun your program, press the reset button on the back of your micro:bit. The reset button automatically runs the newest file on the micro:bit.

Send to: If you're using Windows you use Send to in File Explorer:

• In File Explorer, right-click on the hex file (created in Step 2 above), choose Send to, and then MICROBIT.

By copying the script onto the MICROBIT drive, you have programmed it into the flash memory on the micro:bit, which means even after you unplug the micro:bit, your program will still run if the micro:bit is powered by battery.

If you want to save time, you can use the micro:bit uploader to automatically deploy hex files to your micro:bit. It works on Windows and is compatible with any browser.

Troubleshooting

You can’t drag and drop more than one hex file at once onto your micro:bit. If you try to drag and drop a second hex file onto your micro:bit before the first file has finished downloading, then the second file may fail in different ways.

When the first program has been written to the micro:bit, the drive will disengage. If you drag and drop a second file at this point it may not find the drive and the second write will fail.

The errors may look like this:

Windows

Mac

Or it may appear that there are two hex files on your micro:bit so the micro:bit won’t be able to run multiple files. To rectify this, unplug your micro:bit and plug it in again. Make sure that your micro:bit appears as MICROBIT and not MAINTENANCE.

See also

Run code in a browser