Raspberry Pi User Guide

Setting up the system

Required hardware

  • AD-96TOF1-EBZ development kit

  • Raspberry Pi The system was tested on Raspberry Pi3 Model B V1.2 and Raspberry Pi 4. It can work on other models that have a CSI camera interface input.

  • Raspberry Pi 5V power supply

  • To run the system in standalone mode, besides the accessories that are provided in the AD-96TOF1-EBZ box you’ll need an additional HDMI cable to connect to a monitor and a USB keyboard and mouse

  • RPi camera cable for connection between RPi and AD-96TOF1-EBZ

Modifying the AD-96TOF1-EBZ to work with the RPi

For the AD-96TOF1-EBZ rev.B to work with the RPi the following changes must be made on the camera board:

  • short pins 2 and 3 on JP1. JP1 is located underneath the laser board so the laser board must be first detached from the camera board to have access to this solder jumper

  • short R98 and R109

  • move the S1 switch to position 1 - to the dot on the switch

For the AD-96TOF1-EBZ rev.C to work with the RPi the following changes must be made on the camera board:

  • move the S1 switch to position 1 - to the dot on the switch

  • set the S5 switch 1 to OFF and all the other S5 switches to ON

Power on sequence

  • Plug the SD card into the Raspberry Pi SD card slot. To benefit from the most recent software updates it is highly recommended to update the SD card with the latest SD card image

  • Connect the HDMI cable from the monitor to the Raspberry Pi HDMI connector

  • Connect the RPi camera cable between the RPi and the P1 connector of the ToF board

  • Connect a USB mouse and keyboard to the Raspberry Pi. It’s possible to use either a mouse & keyboard combo or a separate mouse and keyboard

AD-96TOF1-EBZ rev.B

  • connect the I2C1 of the Raspberry Pi to AD-96TOF1-EBZ development kit. Please use jumper wires and the table below.

Raspberry Pi GPIO Header (J8)

AD-96TOF1-EBZ pin header (P4)

Pin 3 (SDA)

Pin 17

Pin 21

Pin 5 (SCL)

Pin 15

Pin 19

  • take care that the jumper wire connected to RPi header Pin 3 must be split in two and routed to both Pin 17 and Pin 21 on camera PCB. The same for SCL wire

RPi connections rev. B

AD-96TOF1-EBZ rev.C

RPi connections rev. C

  • connect the 5V power supply to the camera board and set the camera power switch S2 to on. Once the camera board is powered up the DS1 LED will turn on

  • connect the 5V power supply to the Raspberry Pi. Once power is connected to the Raspberry Pi the system will boot the Linux OS from the SD card.

Power off sequence

  • Open a terminal and type sudo poweroff. This will safely power off the Raspberry Pi and ensure that the SD card is properly unmounted

  • remove the 5V supply from the Raspberry Pi

  • Set the camera board power switch to off

Troubleshooting

  • Linux does not boot

    • The SD card is corrupted and this prevents the system from booting. Reflash the SD card with the SD card image.

Running the evaluation application

Once Linux boots you’ll see on the HDMI monitor the Linux desktop and on the top left corner a shortcut to the evaluation application. Double clicking on the icon will start the evaluation application. A console window will open to show the application’s status and, after a few seconds, the evaluation application GUI will be displayed.

aditof-demo

When starting the application, a terminal window will open to display status messages (also warning and error messages, in case there are any issues). Shorty the main window will show up.

The evaluation application allows to do live streaming of depth and IR data as well as recording the depth and IR data and playing back from a file. The depth data is displayed as a color map ranging from warm to cold colors as the distance from the camera increases. A point in the middle of the depth image shows the distance in mm to the target.

There are 3 operating modes that determine the range of the system:

  • Near - 25cm to 80cm

  • Medium - 30cm to 4.5m (Rev.B: 80cm to 3m)

  • Far - 300cm to 600cm

When in a certain operating mode the system will measure distances outside of the mode’s range but those will not be accurate.

The system is factory calibrated to achieve high accuracy in all the operating modes for indoor environments. It is possible to recalibrate the system for your specific operating conditions by using the calibration procedure and tools provided here.

The evaluation application also displays the temperature in deg C of the camera (AFE) and laser boards as read from the temperature sensors installed on each board.

The framerate at which data is acquired from the system is constantly updated on the GUI. The camera board outputs data at 30 frames per second (fps), but due to USB connection limitations, the host PC acquires the frames at a lower rate.

Enabling the point cloud display in aditof-demo

  • The demo application has the capability to display a point cloud image if it detects an OpenCV module called viz.

Unfortunately OpenCV does not provide binaries for this module so a manual build is needed. The steps required to install OpenCV and include it in the project are presented here: Windows Linux

  • If aditof-demo finds all the OpenCV required modules a button in the interface will allow you to display the point cloud. By toggling the button a separate window will appear.

aditof-demo

Important

Due to the limited computation speed of DragonBoard410c it is recomended to enable the point cloud only in the desktop sdk

Troubleshooting

  • The demo application hangs after closing the main window

    • Due to some limitations the application always hangs if it is closed using the regular X button from the window top bar (title bar). To avoid this unpleasant hang, we’ve made available a second X button in the top right corner right above the title bar that can be used to safely close the demo application. We hope this to be a temporary workaround.