Troubleshooting

This page documents common problems and their solutions.

Hardware problems

The status LED is throbbing and I can’t upload my program!

The LED throbs when there has been a failed software assertion.

You can still reprogram by resetting the board and uploading during the short window when the bootloader waits for a program.

To make this window longer (it can be hard to get the timing right), use perpetual bootloader mode.

My board is bricked! I can’t upload via the bootloader no matter what!

Use the hardcoded serial STM32 serial bootloader to re-flash the bootloader.

If it really is bricked, and you think it’s our fault, contact us!

My 5v peripheral doesn’t work! (I2C, SPI, USART, etc)

Yup, the Maple is a 3.3v board. You may need to use a level converter. See the compatibility, GPIO, or other hardware specific documentation for more information.

The reset and D38/serial buttons don’t seem to work reliably!

A few rev3 boards shipped in May-June 2010 may have had unreliable buttons; see the errata page for details. We’re happy to replace these for you!

Installation problems

I don’t have root/administrator access!

There are probably hacks or work-arounds to getting programs uploaded without higher level system permissions. If you can access USB character devices (ACM or ttyUSB style), you should be able to communicate with the Maple and reprogram using an FTDI converter and the serial bootloader, but we haven’t tried.

[Linux] I don’t use udev!

There is probably a simple way to get autoconfiguration working with devfs; in the meantime, you could try running the entire IDE as root.

IDE problems

[Mac OS X] The “Board” and “Serial Port” menu items are missing!

Sometimes this happens if you try to compile or upload without having a board selected. The work-around is to restart the IDE. Mysterious!

Common compiler problems

NullPointerException

A classic! Make sure you have selected a board from the pulldown menu.

undefined reference to setup()/loop()

Your sketch/program either does not include one of the setup() or loop() functions, or it was not found by the compiler. Your program must include both void setup() and void loop() functions; they don’t have to do anything, but they must be there.

You can start with an example program (to see one in the IDE, click on File > Examples > Stubs > BareMinimum) to get the basic structure. See also the language documentation.

This is a common error when your entire sketch is blank.

error: 'Serial' was not declared in this scope

The classic Arduino has only one USART device and uses the unique name “Serial” to control it. Larger devices like the Arduino Mega and the Maple have multiple USARTS referred to as Serial1, Serial2, etc. You probably want Serial2 on the Maple; that’s the one connected to pins D0 and D1. See also the USART docs.

File(s) not found

There is an intermittent bug with the temporary directory build system that on occasion will lose many of the #included libmaple files. If you recompile everything, it should be fine.

Common upload problems

My program is too large!

First, make sure you’re using the FLASH target instead of RAM; there is several times more FLASH memory available for user programs.

No DFU capable USB device found

This probably means you don’t have a Maple plugged in or powered on. Try unplugging and plugging your Maple or pressing the RESET button.

This can also happen if you disable the USB peripheral, e.g. using SerialUSB.end().

I have multiple Maples installed; how do I know which one will get flashed?

Because the Maple IDE uses DFU to upload programs, you can’t select a particular Maple from the Serial Port menu to upload to a particular board. There’s no solution to this problem for now: you’ll have to just plug in the Maples one at a time. If this is a real problem let us know and we’ll see if we can come up with a better solution.

My flash programs don’t seem to stick; they behave like they are RAM!

If you have uploaded a program to RAM, this will take priority over any program subsequently uploaded to flash. We’ll be removing this bug in a later version of the bootloader. For now, you can fix this by unplugging your Maple to clear the contents of RAM, then plugging it back in.

If you are using the Unix toolchain, Make sure you make clean when switching between FLASH and RAM targets; make isn’t smart enough to rebuild everything that needs to be for the new target.

Command-line issues

[Linux] cdc_acm 3-1:1.0: no more free acm devices

This is a nasty one! It means that all 32 possible CDC_ACM serial devices (/dev/ttyACM25, etc.) have been used up.

The usual cause is using a serial port monitor and not closing it before restarting the Maple or uploading a new program. The operating system doesn’t like that, and locks up that device. After reset the Maple comes back up as a new device. If you develop heavily and don’t restart you’ll blow right through all 32 devices.

The lazy solution is to always close the monitor before restarting, and if you get this error in dmesg after a dfu-util “Not Found” error, restart you machine.

The hacker solution is to restart your cdc_acm kernel module. On Ubuntu 09.10, this goes a little something like:

$ sudo rmmod cdc-acm
$ sudo insmod /lib/modules/2.6.31-20-generic/kernel/drivers/usb/class/cdc-acm.ko

Tips and Tricks

Perpetual Bootloader Mode

In this mode, Maple stays a DFU device and does not jump to user code until the next reset. This is useful for guaranteeing that your Maple will be available for reprogramming.

To put your Maple into perpetual bootloader mode:

1. Plug your Maple into the USB port.
2. Hit the reset button on your Maple (it’s the small button at the bottom left, labeled RESET). Notice that it blinks quickly 6 times, then blinks slowly a few more times.
3. Hit reset again, and this time push and hold the other button during the 6 fast blinks (the button is on the top right; it is labeled BUT). You can release it once the slow blinks start.