Project 4 XGO Wave Hand

Ⅰ. Teaching Aims

Recognize the three joints of Upper / Middle / Lower, and focus on the combined control of Middle and Lower.
While sitting, wave the claw three times by repeat.
After the action is completed, play a beeping sound as multimodal feedback.
Understand the importance of XGO reset pose for clearing cumulative errors.

XGO + Foxbit + MicroBlocks IDE.
XGO battery power ≥ 60 %.
MicroBlocks status bar shows a green dot, and the development board model is Foxbit.
Test XGO init and XGO reset pose.
Leave a gap in front of the desktop to prevent the claw from hitting objects.


Functions	Make the dog sit steadily
Tips	It’s safer to sit firmly before waving claw

Functions	The front paws swing back and forth
Parameter sample	30 / −30 / 0
Tips	angle > 0 ＝ Wave forward

Functions	Flexion and extension of the wrist
Parameter sample	10 / 0
Tips	Change posture in coordination with Middle

Functions	The sequence of circular claw swings
Parameter sample	3 times
Tips	At the end of the loop, be sure to return to the original position

Functions	Give the servo time to be in place
Parameter sample	500 ms
Tips	delay ≥ 300 ms for clearer movement
`play tone Note ms`
Functions	Beeping sound
Parameter sample	G5 120 ms
Tips	Put it after the loop

Drag in the initialization block: when started → XGO init → XGO reset pose → XGO action Sit Down
Piece the main action logic as shown:
Click ▶Run, and the dog will “wave while sitting × 3” and then reset.

Online code: Click here

Why must Sit Down first and then wave the claw?
What will happen if the Lower joint is not reset to 0° and this cycle is repeated many times?
How to change “wave once” into a waveOnce() custom Block, and then call it by repeat?

Questions	Possible causes	Solutions
Sit down but do not wave	`repeat` is empty or omits joint instructions inside	Check the loop content
The amplitude is too small	Middle° is too low	Set up to 25–35°
“wrist” is not bent	Lower° = 0°	set 8–12°
The servo is shaking/screaming	The angle exceeds the limit or touches the table	Reduce the angle and remove the obstacle
The second and third movements are deformed	There is a lack of reset within the loop	After each waving, set Middle, Lower = 0°
The program ends in a strange posture	Forgot `XGO reset pose`	Add it before the end