-------------------- Tech Support Tips/Troubleshooting/Common Issues --------------------

Bricked Atmega32U4 (i.e. your Pro Micro disappeared from your Device Manager)

Timing Issues w/ USB Communication through CDC

Interrupts Atmega32u4's built in CDC driver for USB communication can have timing issues when messing with the watchdog timer, sleep modes, and timer interrupts. I am unsure of how to fix this issue if you continue to use code that interferes with the CDC. I recommend trying a different method than using the interrupt timers.

Wrong Bootloader It's possible to brick your ATmega32U4 w/ Arduino bootloader if you used the wrong board selection with the wrong frequency. If you upload the wrong frequency, the IC will not be able to understand any new code that is being uploaded. It expects to have code that is compiled for another bootloader, instead of using its configured frequency with the oscillator.

When either of these cases happens, the device manager is not able to recognize the device and is usually seen as an "unknown device" when the microcontroller runs the sketch. There are ways to recover the an Atmega32U4 (i.e. LilyPad Arduino USB - Atmega32U4 board, FioV3 - Atmega32U4, Pro Micro 5V/16Mhz, Pro Micro - 3.3V/8Mhz, etc) if this happens. Check below for more information:

Here is a more in depth tip on recovering Atmega32U4s with different bootloaders listed in the product page's tech tips tab:

• 5V/16MHz Pro Micro

• 3.3V/8Mhz Pro Micro

• 3.3V/8MHz FioV3

• 3.3V/8MHz LilyPad Arduino - USB

• 3.3V/8MHz QDuino

 
Pro Micro Not Executing Code w/ Remote Power?

If your Pro Micro works on a computer but does not when you power it remotely with a external power supply, it's possible there is a piece of code waiting for a a serial connection before the rest of the code executes. Makes sure that you do not have this in your code when the Atmega32U4 is not connecting to a computer's COM port:

void setup(){
    Serial.begin(9600);
    while(!Serial){
    ; // wait for serial port to connect. Needed for native USB
    }
 }

The CDC port of the Atmega32U4 based Arduinos might be causing the microcontroller to get stuck in the loop => https://www.arduino.cc/en/Serial/IfSerial .

Issues Installing the Drivers?

I just tested a 5V Pro Micro on a Windows 10 and I did not have any issues installing the drivers. The driver files do not indicate it is for Windows 10 but it somehow was able to still work. I recommend trying to follow the instructions listed on the hookup guide for more information => https://learn.sparkfun.com/tutorials/pro-micro--fio-v3-hookup-guide#installing-windows . The only difference is that you are using signed drivers. Therefore, there will not be a pop up window with a warning message that shows up. By unzipping the downloaded files, you will find the signed drivers probably in a location similar to this:

C:\...\Arduino_Boards-master\Arduino_Boards-master\sparkfun\avr\signed_driver

Try using the latest drivers in GitHub if you still have issues => https://github.com/sparkfun/SF32u4_boards/tree/master/sparkfun/avr/signed_driver

USB Port Issues and Drivers

You can have issues using the Pro Micro if you are connecting to a USB3 port. The drivers will not install correctly unless they use a computer with USB2.0 port.

There was an issue when a customer was using it on a Windows 7 64-bit OS. When connecting to a USB3 port the Pro Micro can report the hardware ID as:

USB\VID_1B4F&PID_9206

When connected to a USB2 port the Pro Micros should report the hardware ID as:

5V/16MHz

USB\VID_1B4F&PID_9206&REV_0100&MI_00
USB\VID_1B4F&PID_9206&MI_00

3.3V/8MHz

USB\VID_1B4F&PID_9204&REV_0100&MI_00
USB\VID_1B4F&PID_9204&MI_00

The current version of the SparkFun FioV3 should be:

USB\VID_1B4F&PID_F101&REV_0100&MI_00
USB\VID_1B4F&PID_F101&MI_00

Arduino Error

If your Pro Micros were working initially and then you have this error output after updating to Arduino v1.6.9, you might need to uninstall/delete the preferences.txt file:

.
.
.
exec: "avr-g++": executable file not found in %PATH%
Error compiling for board SparkFun Pro Micro 5V/16MHz

There was a case where a customer had to reinstall Arduino IDE v1.6.9 a few times before getting their code to compile

"To clean uninstall or reinstall, after doing Windows Uninstall, you have to rename or delete the preferences.txt file. Its path is given at the bottom of the File->Preferences dialog..."

Pro Micro with Visual Studio

An alternative to programming the Arduino IDE is using Visual Studio. A customer was able to upload code to their Pro Micros using Visual Studio. Here are some tips from the customer:

"The Visual Studio IDE (C++ installation with Visual Micro Arduino add-on) is significantly easier to use than stock Arduino IDE. Furthermore, unlike Arduino which compiles all files every time, Visual Studio recompiles only changed source files, greatly speeding up the debug/test cycle. The Visual Micro Arduino add-on will work with the ProMicro provided ProMicro already works with the Arduino IDE (Arduino 1.0.6 is known to work with ProMicro and with VS2010). The Visual Micro add-on requires Arduino software to be installed because it invokes their gnu cross-compiler and linker. For BlinkProMicro to run: a) do not select a programmer as suggested by the Visual Micro site, and b) to see serial data appear in the monitor, be sure to check DTR at the bottom of the monitor window."

Problems Opening a COM port on Linux

There was a customer that had an issue on their Ubuntu Linux preventing them from accessing the enumerated port when a Pro Micro was connected. There is a fix by configurating some settings. Check below for more information:

"On Ubuntu Linux, the modem manager was grabbing the Pro Micro as soon as it was plugged in, preventing anything else, such as the Arduino IDE from being able to open the port. This is apparently a known issue, but I had to go search it down, as there is no mention of it here...

Fix:

sudo echo 'ATTRS{idVendor}=="1b4f", ENV{ID_MM_DEVICE_IGNORE}="1"' > /etc/udev/rules.d/77-arduino.rules

I found the explanation and fix on http://starter-kit.nettigo.eu/2015/serial-port-busy-for-avrdude-on-ubuntu-with-arduino-leonardo-eth/"

Issues Uploading on Linux

If you have problems uploading code with this error using the Pro Micro on a Linux machine:

 avrdude: ser_recv(): programmer is not responding
 avrdude: butterfly_recv(): programmer is not responding

try following these instructions from Arduino => http://forum.arduino.cc/index.php?topic=217910.0. They need to change some udev rules. There was a customer had the same problem but got it working after changing the settings.

Arduino IDE Automatically changing COM ports

If you are using a device with the Atmega32U4 (like the Pro Micro or Arduino Fios) Arduino v1.6.3 will keep the same COM port after uploading. If you upload code using Arduino v1.6.5, the IDE will switch the COM port automatically when it is in bootloader mode. Once the sketch runs, the Arduino IDE v1.6.5 will not automatically switch it back to the COM port that the sketch runs on. You need to manually select the COM port if you want to upload or use the serial monitor.

Uploading with XBee Attached to FioV3

When an XBee is attached to the FioV3, you are able to still upload code. Looking at the Eagle files, the USB data lines are tied to the USB data pins of the Atmega32U4. This should be a separate line compared to the hardware UART lines that the XBee is attached to. The Atmega32U4 communicates with the hardware UART pins with the serial and serial1 functions. I tested this case 4 times and was able to still upload code to the FioV3 and connect to the XBee through the XCTU.

Sending Characters through XBees with FioV3's Header Sockets

Not seeing serial data when an XBee is attached to the FioV3? Make sure to use the correct function as stated in Example 1 of this tutorial. Feel free to use this modified serial passthrough code based on some of Jim's example codes [ https://github.com/bboyho/Atmega32U4Serial_Passthrough/blob/master/Atmega32U4Serial_Passthrough.ino ].

With Arduino 1.6.6, the Arduino add-on package that is linked by this tutorial has some deprecated path variables that can be fixed, but you can avoid this issue by following the instructions for the adding sparkfun's boards to the board manager and using that to install the Arduino add-on here: https://github.com/sparkfun/Arduino_Boards

How to make a USB Powerbank keep providing power?

My code works fine when plugged into a computer, and it also works fine when powered by a USB Powerbank, for a while (20-30 seconds). But, the current draw is relatively low (10mA most of the time, up to 200 mA when a micro-servo is active). The powerbank is going into an "auto-off" mode (I assume because the average power draw is so low). I have considered adding a resistor to increase the power draw, but this seems silly for a battery powered device.

I was wondering if anybody had code/tips for how to "fake" being a phone and telling the USB charger to keep providing power even though the current draw was low via the USB port?

Do I still need to do all that complicated installing addons & drivers when using Pro-Micro with ArduinoIDE 1.8.5? I mean that when I choose board with atmega32u4 and right COM I was able to use SparkFun Blinkes! sketch as it is but I'm having trouble with some other sketches. And I find RXled & TXled controlling bit tricky too, any tips for that? For example I wasn't able to dim them. Thanks.

-SuperNoob

I'm confused about the pin mapping. If I use raw0 = analogRead(A6); // pin 4 raw1 = analogRead(A7); // pin 6 then A6 and A7 seem to be the correct way around. But if I do raw0 = analogRead(4); // pin A6 raw1 = analogRead(6); // pin A7 then the inputs are reversed, but according to the diagram, A6=pin 4 and A7 = pin 6. Have I got it wrong?

I seem to have bricked both ProMicro's I ordered. One of them I have been able to recover with the double tap to the reset button and quickly uploading it to the bootloader serial.

The other I can't seem to do the same trick. The bootloader serial port shows up on my mac for 8 seconds as it should, if I do nothing: crw-rw-rw- 1 root wheel 18, 109 Mar 15 12:21 /dev/cu.usbmodem14131 but then as soon as I hit upload in the Arduino IDE, it disappears again, and the IDE complains it can't find the board.

Any tips welcome.

The V1.3B (Pro_Micro_v13b.pdf) schematic identifies D9 shared with A8, but the Hookup Guide shows D9 shared with A9, and D8 shared with A8. There is no A9 on the schematic. Can anyone help clear up the confusion please? Thanks

Correction to guide: TXLED1 turns off LED... not on...

Hi,

i ve a little problem with the pro micro. it always connects as usb-hid-device :

Bus 001 Device 089: ID 2341:8036 Arduino SA Leonardo (CDC ACM, HID)

when i double shorten rst & gnd it will be for 8seconds:

Bus 001 Device 092: ID 2341:0036 Arduino SA

but there is no /dev/ttyUSBx so i cant select a port in ARDUINO 1.6.8 (tools\port\serial ports are grayed there are only tools\port\"/dev/ttyUSB0, /dev/ttyUSB1") if i connect a arduino uno or via ftdi an arduino mini i'll get "/dev/ttyUSB2" and i can program it.

i also tried this: sudo echo 'ATTRS{idVendor}=="1b4f", ENV{ID_MM_DEVICE_IGNORE}="1"' > /etc/udev/rules.d/77-arduino.rules but no success =(

i can see with dmesg how the MICRO switches (disconnect after 8sec and reconnect as HID-Device). Perhaps i forgot a special kernel option (make menuconfig)

thanks for help

Hello, I am not quite sure why, but the current release of the Arduino IDE (1.6.7) is throwing the following error:

exit status 1 'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?

Thoughts?

Is there any way to get the Pro Micro to work with 64 bit Windows 7? The only drivers I can find are for 32 bit systems.

my mac is not recognizing the fio v3. I am running yosemite - any ideas on how I can get it to recognize?

I goofed :-(, excellent tuto !

What is the type of the USB connector? There are several types of the mini and micro. Thanks

I'm a bit confused on the FIO hookup guide. I was under the impression the I2C connections are on A4 & A5. Though the image shows them on D2 & D3. Which is correct?

It looks like pins 14 and 17 are swapped on the hookup guide (hopefully not swapped on the board!).

Can you confirm/deny this is the case?

As mentioned in this tutorial the Arduino add files on do not work for Arduino V1.5. I have fixed this and put up a set of files that work with Arduino V1.5.5 These are available from http://www.forward.com.au/pfod/ArduinoProgramming/FioV3/index.html