Debug - Re-flash Microcontroller#

What you will need

  • A Duckiebot of configuration DB18 or above.

  • A stable network connection to your Duckiebot.

What you will get

  • A flashed microcontroller (not SD card) on the HUT board, with the latest code version.

Warning

This procedure is needed only if your Duckiebot does not recognize the HUT (Dashboard > Robot > Components). Although often unnecessary, it is safe to perform on any HUT of version 2.0 and above.

When and why should I run this procedure?#

This procedure flashes the microcontroller on the Duckietown HUT. This microcontroller is responsible for translating the duty cycle commands from the onboard computer to actual PWM signals that control the motors and the LEDs (because they are “addressable” LEDs) of the Duckiebots.

A typical example of when is necessary to flash the microcontroller is when commands are sent to the motors, e.g., through keyboard control, the motors signals on the dashboard/mission control show that signals are correctly being sent, but the Duckiebot does not move.

This procedure will not be useful to fix problems such as one motor working and not the other, or LEDs showing unexpected colors when the motors work.

How to flash the microcontroller#

SSH into your Duckiebot by running:

ssh duckie@![ROBOT_NAME].local

Note

All of the following instructions are run on Duckiebot throught he SSH terminal

Install the packages needed to compile the microcontroller firmware:

sudo apt-get update
sudo apt-get install bison autoconf flex gcc-avr binutils-avr gdb-avr avr-libc avrdude build-essential

Clone the firmware for the microcontroller using the following command:

git clone https://github.com/duckietown/fw-device-hut.git

Navigate inside the repository you cloned :

cd fw-device-hut

Warning: read the next passages carefully. Do not just copy and paste every line of code!

Copy the avrdude.conf file in the /etc folder of the robot. If you are running a Duckiebot with an NVIDIA Jetson Nano board run:

sudo cp _avrdudeconfig_jetson_nano/avrdude.conf /etc/avrdude.conf

else, if you have a Raspberry Pi based Duckiebot, use:

sudo cp _avrdudeconfig_raspberry_pi/avrdude.conf /etc/avrdude.conf

Then, test the avrdude and set the low-level configuration with:

make fuses

A successful outcome looks like:

avrdude: verifying …
avrdude: 1 bytes of efuse verified

avrdude: safemode: Fuses OK (E:FF, H:DF, L:E2)


avrdude done.  Thank you.

If you see the message make: warning: Clock skew detected. Your build may be incomplete. or the process is not stopping, stop the process pressing Ctrl-C and run:

find -exec touch \{\} \;

And then retry running the make fuses command.

To complete the procedure (in all cases, whether or not a warning was issued), remove all temporary files by running:

make clean

Compile the firmware and upload it to the microcontroller:

make

The resulting output should be:

```none
.....

sudo avrdude -p attiny861 -c linuxgpio -P  -q -U flash:w:main.hex

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e930d (probably t861)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
     To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "main.hex"
avrdude: input file main.hex auto detected as Intel Hex
avrdude: writing flash (2220 bytes):

Writing | ################################################## | 100% 0.75s

avrdude: 2220 bytes of flash written
avrdude: verifying flash memory against main.hex:
avrdude: load data flash data from input file main.hex:
avrdude: input file main.hex auto detected as Intel Hex
avrdude: input file main.hex contains 2220 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.58s

avrdude: verifying ...
avrdude: 2220 bytes of flash verified

avrdude: safemode: Fuses OK (E:FF, H:DF, L:E2)

avrdude done.  Thank you.
```

Remove the cloned repository to free up space:

cd .. && rm -rf fw-device-hut

and finally reboot the Duckiebot:

sudo reboot

After reboot your Duckiebot should move normally and LEDs respond nominally. The Dashboard / components page will show a green status for the HUT, too.