Donkey Car Jetson Nano Edition�Assembly Guide

Robocar Ltd

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Please contact hi@robocarstore.com for licensing this material to be used in classroom or other occasion.

Copyright © 2019 Robocar Ltd

Assemble the hardware

45 minutes

Step 1

Mount Hexagon Standoff Spacer to Base Plate��Material:

1. 4 x m2.5 x 20mm Standoff
2. 8 x m2.5 x 5mm Standoff
3. 12 x m2.5 nuts

Step 2

Attach Servo Driver, and Voltage Converter to Base Plate��Material:

• PWM Controller + 4 x m2.5 screw
• 5V converter + 2 x m2.5 screw

Step 3

Mount the standoff on the adapter

�Material:

• Adapter
• 4 x m2.5 screws and nuts

Step 4

Attach the Jetson Nano Adapter to the base Plate��Material:

• Adapter
• 4 x m2.5 screws

Step 5

Install the Wifi Card

• Unpack the Jetson Nano
• Remove the 2 module screws
• Release latches which hold the module in place
• Remove the Jetson Module from the carrier board

Step 6

• Attach the antennas to the WiFi card
• Install and secure the WiFi Card
• Install the Jetson Module back to the carrier board

Step 7

• Carefully unlock the latch of the camera interface on the board
• Attach the camera cable to the board
• Secure the camera cable using the latches

Warning: The latches are very fragile. Apply extra care when you lock and unlock the latches

Step 8

Secure the Jetson Nano on the adapter��Material:

• Jetson Nano
• 4 x m2.5 screws

Step 8

Step 9

Connect the PCA9685 to the Jetson Nano

There are four pin named GND, SCL, SDA, VCC on the PCA9685. They should be connected to the Jetson Nano pin 1,3,5, 9 correspondingly. �

Step 9

Step 10

Connect the USB cable from the 5V converter to the Jetson Nano

Step 11

Slide the camera into the cage as shown

Step 11

Step 12

Fix the cage to the base plate using the m2.6x8mm PT screws

Turn the cage and the base plate upside down will be easier to secure the cage

Step 13

Attach the splitter wire to the 5V converter

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Warning: Be careful the red wire should go to the +ve and black wire should go to the -ve. You may damage the battery and all electronics if you connect incorrectly

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Step 13

Attach the base plate on the HSP94186 RC car

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Step 13

You can secure the base plate using the clip provided

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Step 14

There are two wires coming from the ESC and the servo. They should go through the oval outlet of the base plate.

Connect the two wire to the channel 0 and channel 1 of the PCA9685

The one coming from the ESC should connect to channel 0 and the one coming from the servo should connect to channel 1

Step 14

Step 15 - Flash the SD card

• Download our pre-built image and flash the SD card using Etcher

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Download Pre-built image here:

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https://www.dropbox.com/s/uzvsmf6j3s9fqw8/jetson_nano_dk_302.zip?dl=0

Copyright © 2019 Robocar Ltd

Step 16

Install the SD card

Step 17

Connect the battery to the ESC and the 5V converter

There is a switch attached to the ESC. Turn it on if you haven’t done so.

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Step 18

You will see the Jetson Nano, 5V converter, ESC and the PCA9685 light up as this picture

The 5V converter shows the voltage of the battery and you should not use it below 7V.

Step 19 - Connect to Wifi

If you are using our pre-built image, the Jetson Nano will become a wifi hotspot.

1. Connect your PC to the hotspot�SSID: nano, Password: asdfasdf
2. Connect via SSH��Username: nano, password: asdfasdf
3. Execute the following command to connect to your wifi network��
4. For wifi network that is added previously, use the following command

$ sudo nmcli conn down id Hotspot; sleep 5; sudo nmcli device wifi connect <another_ssid> password <another_password>

$ ssh -l nano nano.local

$ sudo nmcli conn up <Conn_id>

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Step 19 - Connect to Wifi

If you are using our pre-built image, the Jetson Nano will become a wifi hotspot.

• Connect your PC back to your wifi network
• Test connection via ssh again�

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$ ssh -l nano nano.local

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Step 20 - Expand the filesystem

• Check the existing partition information���������You can see that on a 32GB SD card, the size shown is only 14GB�* This is because we shrink the partition to allow a smaller SD card image

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$ df -h

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Step 20 - Expand the filesystem

• Follow the steps of this video to expand the filesystem���������

Copyright © 2019 Robocar Ltd

Step 21 - Test PCA9685

Use this command to test

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$ sudo i2cdetect -r -y 1

Step 22 - Test Camera Connectivity

Use this command to test

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This will create a file under /tmp/test.jpg. You can use sftp to copy the file back to your local PC to check the image

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$ gst-launch-1.0 v4l2src num-buffers=1 ! jpegenc ! filesink location=/tmp/test.jpg

Step 23 - Update myconfig.py

Update the camera type

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CAMERA_TYPE = "CSIC"

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PCA9685_I2C_BUSNUM = 1

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IMAGE_W = 224

IMAGE_H = 224

CSIC_CAM_GSTREAMER_FLIP_PARM = 6

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Step 23 - Start the donkey car software

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Go to http://nano.local:8887 and you can check whether the camera is correctly attached to the system.

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$ python manage.py drive

Step 23 - Start the donkey car software

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Go to http://nano.local:8887 and you can check whether the camera is correctly attached to the system.

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$ python manage.py drive

Finished!

MM1

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Go to http://nano.local:8887 and you can check whether the camera is correctly attached to the system.

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$ sudo minicom -D /dev/ttyTHS1 -b 115200