Using URSA

Here's how to use an URSA!

1. Put 8 charged NiMH batteries into the battery pack.
2. Turn the robot on by connecting the 9v snap to the battery pack.
3. The blue RSL light on the esp32 should start flashing quickly.
4. If you have a decorative shell to add, put it on now that you don't need to access the battery snap.
5. URSA needs to zero its gyroscope. Lay it down on the floor so it is not moving.
6. The flashing light should stop, turn off, and after about a second turn solid.
7. Solid RSL means the robot is ready, and disabled.
8. Open the Ursa Driver Station program on your device.
9. Open the wifi menu and connect to the wifi network named SERT_URSA_[insert the ID ## of your robot]
10. The wifi should connect (it may warn that the robot isn't a connection to the internet - true but not a problem).
11. The DS should show it is connected with an indicator and/or changing values for voltage and pitch.
12. Tip the robot upright to around its balance point.
13. Use the DS to enable the robot.
14. The robot should start to balance, you can let go, and the RSL blinks to show it is enabled.
15. Control options and exactly how they work may depend on the DS program and device. URSA is driven by setting speed and turn values.
16. URSA may not always go exactly the speed you set but you can make it go the speed you want by adjusting the value you send. For example, if you set the joystick to center and URSA keeps moving forward, you can pull back on the joystick some until the robot stops. Sometimes you have to be part of the control loop.
17. If URSA tips over (particularly likely if you drive into something, drive very fast and turn, or go on rough ground) it will automatically disable. If the robot stays connected, just tip it back up and enable again. If the batteries fall out and you lose connection start at step 1.
18. To turn URSA off, disconnect the 9v battery snap.
19. When the total battery voltage drops to about 8v the motor drivers stop working (this looks like a wheel stopping and the robot spinning and falling over). URSA needs a change of batteries.
20. The range of the wifi connection is about 100-200 feet. The signal strength should be shown by how many "bars" the DS device shows the connection with.
21. Many of URSA's parts run hot, if you can't touch a part (especially the heatsinks on the esp32 and motor drivers) give the robot a rest and check for shorts and disconnected wires. If the part isn't "ouchie ouchie" hot, just hot, that's normal.
22. The advanced settings menu (it should be in the DS somewhere, look for a boring looking button) lets you set the PID constants for both the angle controlling loop and the speed controlling loop. The robot can keep these values saved even when it is powered off, so it should start with good values. The values update live to the robot as you adjust them. See the PID page for some more information on how the PID loops work, but tuning the loops is mostly trial and error - there aren't many rules. Depending on the DS you may need to press a "save settings" button if you want the robot to keep the new settings between power cycles. If you want to revert to the saved settings there may be a "recall settings" button or you can restart the DS since it should ask for a setting recall on reconnection.
23. Disconnect the esp32's 5v pin from the rest of the circuit and disconnect the batteries before reprogramming the esp32.