It works fine when the board is plugged into the Mac via USB, but once I disconnect from there and plug the board into a usb 5v charger the sketch doesn’t seem to boot.
Please post your full sketch.
If possible, you should always post code directly in the forum thread as text using code tags:
- Do an Auto Format (Tools > Auto Format in the Arduino IDE or Ctrl + B in the Arduino Web Editor) on your code. This will make it easier for you to spot bugs and make it easier for us to read.
- In the Arduino IDE or Arduino Web Editor, click on the window that contains your sketch code.
- Press “Ctrl + A”. This will select all the text.
- Press “Ctrl + C”. This will copy the selected text to the clipboard.
- In a forum reply here, click the “Reply” button.
- click on the reply field.
- Click the </> button on the forum toolbar. This will add the forum’s code tags markup to your reply.
- Press “Ctrl + V”. This will paste the sketch between the code tags.
- Move the cursor outside of the code tags before you add any additional text to your reply.
- Repeat the above process if your sketch has multiple tabs.
This will make it easy for anyone to look at it, which will increase the likelihood of you getting help.
If the sketch is longer than the 9000 characters maximum allowed by the forum, then it’s OK to add it as an attachment. After clicking the “Reply” button, you will see an “Attachments and other settings” link.
When your code requires a library that’s not included with the Arduino IDE please post a link (using the chain links icon on the forum toolbar to make it clickable) to where you downloaded that library from or if you installed it using Library Manger (Sketch > Include Library > Manage Libraries in the Arduino IDE or Libraries > Library Manager in the Arduino Web Editor) then say so and state the full name of the library.
-Can I reset the board completely (as in factory reset)?
-What are the functionalities of the reset button (apart from the obvious reset) and why does pulse yellow after being pressed twice?
When you press the reset button twice you put the board into bootloader mode, where it waits for an upload without running your sketch. The reason this is useful is because the USB code that causes your Nano 33 BLE Sense to be recognized as a serial port on your computer is running in the background on the same microcontroller your sketch code is running on. This means that a bug in your code can break the USB functionality and cause the Nano 33 BLE to no longer be recognized by the computer. That would break the ability to upload a new sketch. Luckily, the bootloader code that facilitates the uploads to the microcontroller runs in a special section that is not affected by your sketch code and runs its own USB code. So you can recover from that situation by putting the board in bootloader mode, selecting the port from the Arduino IDE’s Tools > Board menu (the board may have a different port when in bootloader mode than when running your sketch), and then doing an upload.