cpr-documentation/components/husky_a300/husky_a300_electronics_tray.mdx at 2be75123cf5c19ad4da4828b6db377062155d9a8 · nvanheyst/cpr-documentation

Electronics Tray

Top Plate Removed, With The Husky's Front Surface On The Right Side Of The Image

Once you have opened Husky's top, the first thing you see is the Electronics Tray. This tray includes the:

Husky's System Interface Assembly circuit board
Primary computer
IMU
Optional secondary computer or graphics card, (not shown in the image)
Optional USB hub, (not shown in the image)

You may want to remove the Electronics Tray to access the integration bay under the tray, or to maintain Husky's Batteries and Power Distribution components.

Hinging The Electronics Tray

Tray Hinged, And Then Held With A Prop Rod

To hinge the tray:

Shut off the Circuit Breaker
Remove the Top Plate or Enclosure from the Husky
Disconnect the motor cables, (2 per motor, so 8 cables total)
Disconnect the computer's Ethernet cable from the network switch
Disconnect the large orange connector near the rear-right of the robot. This connector provides main power, and mobility power to the Electronics Tray.
Remove the tray's 2 front screws
Loosen the tray's 2 rear screws, (these will become the tray's hinge pin)
Lift the front of the tray

:::note

When reinstalling the tray:

Torque the tray's 4 screws to 3 N·m.

:::

:::danger Exposed +V Batteries

Lifting the tray will expose Husky's batteries. The batteries's exposed +V terminals are always live, even when Husky's circuit breaker is in the Off position. The batteries are fused, but can still produce an electric arc if shorted to ground.

Wear protective equipment to guard your skin and eyes.

Keep the workspace clean, without any combustable materials nearby.

Review your workplace's safety procedures related to fires of LiFePO₄ batteries.

:::

Removing The Electronics Tray

Tray Removed, But Still Tethered By The USB And HDMI Cables

To remove the tray:

Return the tray to the level position, (not hinged)
Take pictures of all the cables and connections to the System Interface Assembly. The cables have labels with names that match the PCBA's silkscreen, but pictures will help you reinstall these cables later.
Disconnect all the cables, _(listed from the left side of the robot, towards the right)_:
1. _(Any cables from your custom integration)_ 2. Front Ethernet cable to the newtwork switch, _(which should have been removed in the previous step)_ 3. 2X Wi-Fi, _(plastic bracket's W1 and W2)_ 4. Current Sensor, _(BATTERY I)_ 5. HMI Display, _(USER INTERFACE)_ 6. Battery CANbus, _(CAN_BAT)_ 7. 2X Status Lights, _(STATUS 1, STATUS 2)_ 8. 2X Large VBAT Contactors, _(UP CTCR1, UP CTCR2)_ 9. 2X Shunt Brake Contactors, _(AUX/SB CTCR1, AUX/SB CTCR2)_ 10. 2X Mobility Contactors, _(M CTCR1, M CTCR2)_ 11. 4X Fans, _(FAN 1, FAN 2, FAN 3, FAN 4)_ 12. Optional, Wireless Emergency Stop Cable, _(W ES)_ 13. Wireless Emergency Stop Disable Keyswitch, _(W ES BYP)_ 14. 2X Emergency Stop Buttons, _(ES1, ES2)_ 15. Limit Switch, _(CHRG INTL)_ 16. Network Switch Power, _(SYS4)_ 17. Main Ground, _(GND)_ 18. Low Battery Shutdown, _(CB KILL)_ 19. Main Contactor, _(MAIN CTCR)_ 20. System Standby Power, _(VSTBY)_ 21. Tray Bond, _(Tray's threaded stud, without identification)_ 22. Leave the USB cable connected 23. Leave the HDMI cable connected 24. Large orange connector _(V MOT and V SYS, which should have been removed in the previous step)_
Remove the tray's 2 rear screws
Lift the tray out of the Husky. Note that the tray is still tethered to the Husky with a USB cable and a HDMI cable. Rotate the tray, and set it behind the Husky.
Disconnect the USB and HDMI cables from the Husky's Debug HMI area.