Project 2 XGO’s First Step

Ⅰ. Teaching Aims

  1. Master the positive/negative values of XGO walk step size and their relationship with the direction of travel and speed.

  2. Use wait … ms to control the duration of one gait.

  3. Write the minimum walking script of “forward - pause - backward” and add a beeping prompt sound.

Ⅱ. Pre-class Check

  • XGO + Foxbit + MicroBlocks IDE.

  • XGO battery power ≥ 60 %.

  • The ground/desktop is flat, and the straight path is no less than 60 cm.

  • MicroBlocks status bar shows a green dot, and the development board model is Foxbit.

  • Run XGO init and XGO reset pose to confirm that everything is normal.

Ⅲ. Key Blocks Analysis

Img

Functions

Keep walking and set the step size

Value range

−100 ~ 100; Positive for forwards, negative for backwards

Fallible points

0 → not move

Img

Functions

Pause the script to maintain the current gait

Value range

ms; 1000 ms = 1 s

Fallible points

Treat milliseconds as seconds

Img

Functions

The buzzer plays notes

Value range

Note C4–B6；ms > 0

Fallible points

Forget the duration → Long beeping

Ⅳ. Test 1: Minimum Walking Script

  1. Retain the first three lines of initialization:

    Img

  2. Add 4 instructions in sequence:

    Img

  3. Click ▶Run and the XGO will perform “Forward - beep - Backward - beep”.

Online code: Click here

Ⅴ. Test 2: Start/Stop Beeping+ Walking

Requirement:

  1. Play C5 once at the beginning and once at the end of the action.

  2. The walking sequence is “forward → stop → backward → stop”.

Reference script:

Img

Online code: Click here

Ⅵ. Quiz

  1. Why does walk step size remain in effect until the next walk instruction appears?

  2. What will happen if we change wait to 100 ms? Try to find the minimum available waiting value.

  3. If you want XGO to make a “woof” sound (buzzer) while moving, where should the play tone be inserted?

Ⅶ. FAQ

Questions

Possible causes

Solutions

Only move forward,
never backward

Forgot to write negative step size

Check the script sequence

Shake/slip while walking

Excessive step size or slippery ground

Reduce the step size;
Pad with cardboard

No sound in the buzzer

The channel is occupied
or the volume is 0

Restart the IDE;
Check the volume slider

Be imbalance while walking

Voltage drop

Pause the test and charge it