So you have got that AIY voice kit for Christmas, and have been playing with it, following the instructions.
It's funny, but now?
The project described in the following presents a simple device that can be build using the AIY voice HAT for the Raspberry Pi. It uses the Google voice recognition system to control LEDs and two servos, driving the arms and legs of a jumping jack by a very simple gear.
The software working in the background is a modification of the servo_demo.py script, as it has been described in the AIY voice kit manual. Just follow the instructions given there to set up hard- and software. The device itself is easy to build and requires not much handcrafting skills. In addition a cutter knife, a drill and a soldering iron would be helpful.
If you activate the voice recognition system with a wink of your hand and say ‘hands up’ the jumping jack will raise hands and legs, 'hands center' will move both servos to the middle position and on ‘hands down’ hands and legs will be lowered. On ‘left up’ the left hand and legs will be raised and on “right down” the right ones lowered, on ‘right up’ vice versa. "Dance", will make it dance, well at least kind of. It is also talking, please have a look on the attached video.
So with little efforts, you can build your own dancing, chatting and singing robot.
To simplify its usage especially by smaller children, and to enhance the ‘magic’ factor, the button on the AIY box was replaced as trigger by a proximity sensor. For its simplicity, I used a digital distance sensor breakout from Pololu which recognizes if an object is closer than 5 cm, and can be use very much like a button. LEDs do indicate when the device is waiting for orders, listening or “thinking”. Servos, sensor and LEDs are controlled by the GPIOZero software library.
The prototype was build from Forex, PVC foam plates, that can be cut very easy with a cutter knife and glued, but is also quite stable. Feel free to build a larger, nicer, improved or more fancy version, but it would be kind if you would document and present your improvements.
You may use both sides of the body, depending whether you want to present the moving gear or have a nice, children-friendly layout.
"Hampelmann" is the German term for "jumping jack", having certain connotations.
Step 1: Materials Used
Raspberry Pi 3; 32 £ at Pimoroni, UK
AIY voice Kit; 25 £ at Pimoroni, UK
Pololu digital distance sensor breakout with Sharp sensor, 5 cm; 5.90 € at Exp-tec.de
Two 9g servos
Two white LEDs and a resistor
Some headers and jumper cables
A 2 mm Forex plate, 250 x 500 mm; 1.70 € at Modulor, Berlin, Germany
M3 screws, nuts and washers, to connect all moving parts. I used six 10 and four 16 mm Nylon screws.
Six M2 screws and nuts, to fix the servos to the plates and connect the servos arms and gears.
A few drops of plastic glue
Step 2: Assembly and Usage of the Device
Concerning the AIY voice kit itself, just follow the instructions in the description that comes with the kit, including the section about the servo. I would recommend to solder several three-pin headers to the servo ports on the AIY voice breakout, so you may connect servos, sensor and LEDs very easy with the HAT.
Concerning the jumping jack, you may either use the drawings I provided here as svg- and PDF-files as a template, or just modify them according to your own ideas. You may like to keep the basic layout of the gear driving the legs and arm of the jumping jack, ensuring that the distance between the pivoting point and the gear is the same at the servo, arm and leg.
Alternatively, you may also construct a version were arms and legs are driven directly by four separate servos, or by a more advanced gear.
Using the drawing, cut the pieces from a Forex, cardboard or plywood plate and drill the holes at the appropriate positions. Glue the distance pieces to the pivoting points of arms and legs, ensuring good alignment of the holes.
Fix the servos and the moving parts to the base plate. Add the distance sensor and LED as indicated. The servos are fixed with M2 screws, all moving parts with M3 screws. I used Nylon M3 screws, but just for esthetic reasons.
Check if the servo arms are placed in the middle position. Connect servo arms and gears, I used M2 screws for this purpose.
Attach servos, LEDs and the distance sensor to the servo connectors on the AIY board. You may need some elongation/jumper cables. I attached the left servo to “servo0” (GPIO 26) the right servo to “servo2” (GPIO 13), the LEDs to “servo5” (GPIO 24), and the sensor to “servo3” (GPIO 5) on the AIY voice HAT.
Copy the provided “Hampelmann.py” file to the AIY “src” subfolder and make it directly executable for anyone. To do so, you may select the file in the file manager, then right click and select Properties, select Permissions, go to Execute, select ~ anyone. Or write “chmod +x src/Hampelmann.py” in the dev console.
Check if everything is set in place and fixed,or movable when required. Open the Dev command line, enter “src/Hampelmann.py” and start the program. If you move your hand or fingers in front of the distance sensor, the AIY unit will ask for orders and the LEDs will blink. Implemented orders are “right/left/hands up/down/center”, “dance”, “LED on/off” and “goodbye”.
Play. Move you hand in front of the sensor, speak when being asked, and give the device a little time to react. Latency is rather high. Crtl+C or “Goodbye” will stop the program.
You may modify the file using Nano or another simple text editor.
Remarks: Please be aware that some words and terms are recognized as words starting with a capital letter, as ‘Center’ or ‘Right Center’, as others are not, e.g. ’right up’. You have to use the exact form given back by the voice recognition module to trigger some action.
Step 3: The Python Script
As mentioned previously, the script is based on the servo_demo.py script from the AIY voice instructions, with some additions. The first version is the Hampelmann.py file you will find attached. AngularServo from GPIOZero allows to restrict the action range of the servo and to define exactly how far shall move.
But I prefer the British voice over the original one. And the device can also speak, but not understand (?), English, German, Italian, French and Spanish. Below you find the Hampelmann2.py script, with the British voice, and a bit of Italian and German. Please keep in mind that you have to make the scripts executable to run them.
<p>#!/usr/bin/env python3<br># This script is an adaption of the servo_demo.py script for the AIY voice HAT, # optimized for the AIY jumping jack import aiy.audio import aiy.cloudspeech import aiy.voicehat from gpiozero import LED from gpiozero import AngularServo from gpiozero import Button from time import sleep def main(): recognizer = aiy.cloudspeech.get_recognizer() recognizer.expect_phrase('right up') recognizer.expect_phrase('right down') recognizer.expect_phrase('Right Center') # the capital letters are there on purpose recognizer.expect_phrase('left up') recognizer.expect_phrase('left down') recognizer.expect_phrase('left Center') recognizer.expect_phrase('hands up') recognizer.expect_phrase('hands down') recognizer.expect_phrase('hands Center') recognizer.expect_phrase('Dance') recognizer.expect_phrase('LED on') recognizer.expect_phrase('LED off') recognizer.expect_phrase('goodbye') aiy.audio.get_recorder().start() servo0 = AngularServo(26, min_angle=-40,max_angle=40) # 1st connector, GPIO 26 servo2 = AngularServo(13, min_angle=-40,max_angle=40) # 3rd connector, GPIO 13 led0 = LED(24) # LEDs are connected to servo5/GPIO 24 distance= Button(5) # distance sensor connected to servo3/GPIO 05 # others: GPIO 6 at servo1, 12 at servo4 aiy.audio.say("Hello!", lang="en-GB") aiy.audio.say("To start, move your hand close to the sensor", lang="en-GB") while True: led0.on() # LEDs on print("To activate voice recognition, move a hand near to the distance sensor, then speak") print('Expected keywords are: hands/left/right up/down/center, ') print('LED on/off, dance and goodbye.') print() distance.wait_for_press() print('Listening...') aiy.audio.say("Please give your orders", lang="en-GB") led0.blink() # light blink text = recognizer.recognize() if text is None: aiy.audio.say('Sorry, I did not hear you.', lang="en-GB") else: print('You said "', text, '"') # Lets you check the systems interpretation if 'right up' in text: print('Moving servo0 to maximum position') servo0.angle=35 elif 'right down' in text: print('Moving servo0 to minimum position') servo0.angle=-35 elif 'Right Center' in text: #correct captials are critical print('Moving servo0 to middle position') servo0.angle=0 elif 'left up' in text: print('Moving servo2 to maximum position') servo2.angle=-35 elif 'left down' in text: print('Moving servo2 to minimum position') servo2.angle=35 elif 'left Center' in text: print('Moving servo2 to middle position') servo2.angle=0 elif 'hands up' in text: print('Moving servo2 to maximum position') servo2.angle=-35 servo0.angle=35 elif 'hands down' in text: print('Moving servo2 to minimum position') servo2.angle=35 servo0.angle=-35 elif 'hands Center' in text: print('Moving servo2 to middle position') servo2.angle=0 servo0.angle=0 elif 'LED off' in text: print ('switching off external LED 0') led0.off() elif 'LED on' in text: print ('switching on external LED 0') led0.on() # light elif 'dance' in text: print ('now performing dance number one') aiy.audio.say("Well, I will try my best!", lang="en-GB") led0.on() # lights on for i in range (3): servo0.angle=0 servo2.angle=0 sleep(1) servo0.angle=35 servo2.angle=-35 sleep(1) servo0.angle=0 servo2.angle=-35 sleep(1) servo0.angle=-25 servo2.angle=0 sleep(1) servo0.angle=30 servo2.angle=20 sleep(1) servo0.angle=0 servo2.angle=0 led0.off() # light off elif 'goodbye' in text: aiy.audio.say("Goodbye", lang="en-GB") aiy.audio.say('Arrivederci', lang="it-IT") aiy.audio.say('Auf Wiedersehen', lang="de-DE") servo0.angle=0 servo2.angle=0 led0.off() sleep (3) print('bye!') break else: print('no keyword recognized!') aiy.audio.say("Sorry, I did not understand you", lang="en-GB") if __name__ == '__main__': main()</p>