The Ravel kit on Zelbinium

Online demonstrations - Ravel kit

Mon, 01 Jan 0001 00:00:00 +0000

Online demonstrations with the Ravel kit#

For use with a simulator (more information here):

Wokwi simulation;

configuration: .

Run button to (re)launch the application. The source code can be modified.

Headless (without GUI)#

Reset#

Resetting the kit

import ucuq ucuq.ravel.raz()

Buzzer#

Beep#

import ucuq FREQ = 440 buzzer = ucuq.ravel.Buzzer() buzzer.on(FREQ) ucuq.sleep(1) buzzer.off()

Scales#

import ucuq FREQ_LOW = 220 FREQ_HIGH = 880 DELAY_TIME = .1 NUM_STEPS = 24 buzzer = ucuq.ravel.Buzzer() coeff = (FREQ_HIGH/FREQ_LOW)**(1/NUM_STEPS) for i in range(NUM_STEPS): buzzer.on(int(FREQ_LOW * coeff ** i)) ucuq.sleep(DELAY_TIME) for i in range(NUM_STEPS + 1): buzzer.on(int(FREQ_HIGH / coeff ** i)) ucuq.sleep(DELAY_TIME) buzzer.off()

RGB Ring#

Plain#

import ucuq R = 10 G = 8 B = 1 ring = ucuq.ravel.Ring() ring.fill((R, G, B)).write()

Rainbow#

import ucuq, random MIN = 1 MAX = 5 ring = ucuq.ravel.Ring() for _ in range(15): for led in range(8): ring.setValue(led, tuple((lambda: random.randint(MIN, MAX))() for _ in range(3))).write() ucuq.sleep(.03) ucuq.sleep(2) ring.fill((0, 0, 0)).write()

LCD#

Simple display#

NAME = """ """.strip().rjust(16) import ucuq lcd = ucuq.ravel.LCD() lcd.putString("Greetings".ljust(16) + NAME).backlightOn()

Waves#

import ucuq DELAY = 0.07 COUNT = 2 lcd = ucuq.ravel.LCD() lcd.uploadUpwardGaugeChars().backlightOn() gauges = () def mirror(str): return str[:8] + tuple(str[i] for i in range(7, -1, -1,)) def morph(a, b): steps = max(abs(x - y) for x, y in zip(a, b)) for s in range(1, steps): ucuq.sleep(DELAY) lcd.putUpwardGauges(0, [int(ai + s / (steps - 1) * (bi - ai)) for ai, bi in zip(a, b)]) for j in range(0, 32 * COUNT): gauges = ((abs((j + 16) % 32 - 16),) + gauges)[:16] ucuq.sleep(DELAY) lcd.putUpwardGauges(0, gauges) morph(gauges, mirror(gauges)) for j in range(0, 32 * COUNT): gauges = ((abs((j + 16) % 32 - 16),) + gauges)[:16] ucuq.sleep(DELAY) lcd.putUpwardGauges(0, mirror(gauges)) morph(mirror(gauges), (0,) * 16) ucuq.sleep(DELAY) lcd.backlightOff()

OLED#

Text#

import ucuq, datetime oled = ucuq.ravel.OLED() oled.text("We are the".center(16), 0, 20).text(f"{datetime.datetime.now().strftime("%d/%m/%Y %H:%M").center(16)}", 0, 40).show()

Drawing#

import ucuq oled = ucuq.ravel.OLED() oled.draw("03c00c30181820044c32524a80018001824181814812442223c410080c3003c0", 16, mul=4, ox=32).show()

Animation#

NOTE: It may take some seconds for the animation to start…

Ravel kit API

Mon, 01 Jan 0001 00:00:00 +0000

Ravel Kit API#

This API is designed for the Ravel Kit and extends the UCUq API. To simplify implementation, it abstracts away the hardware-specific aspects (communication protocols, pins used, etc.).

Buzzer#

ucuq.ravel.Buzzer() (constructor): returns an object for manipulating the buzzer;
for other methods, see ucuq.Buzzer

Ring#

ucuq.ravel.Ring(<offset>) (constructor): returns an object for manipulating the RGB ring. <offset> defines the LED with index 0.
for other methods, see ucuq.WS2812

OLED#

ucuq.ravel.OLED() (constructor): returns an object for manipulating the OLED display;
for other methods, see ucuq.SSD1306_I2C.

LCD#

ucuq.ravel.LCD() (constructor): returns an object for manipulating an LCD display;
for other methods, see ucuq.HD44780_I2C.

Upper#

ucuq.ravel.Upper() (constructor): returns an object for controlling the upper servo;
Upper.set(<value>): sets the servo to the value <value> (between 0 and 6554, inclusive);
Upper.get(): returns the servo’s position;
Upper.park(): sets the servo to its rest position.

Lower#

ucuq.ravel.Lower() (constructor): returns an object used to manipulate the upper servomotor;
for other methods, see ucuq.ravel.Upper.

Ravel#

ucuq.Ravel() (constructor): returns an object used to manipulate the entire kit;
Ravel.raz(): resets all components of the kit;
Ravel.buzzer(): returns the kit’s Buzzer object;
Ravel.ring(): returns the kit’s Ring object;
Ravel.lcd(): returns the kit’s LCD object;
Ravel.oled(): returns the kit’s OLED object;
Ravel.upper(): returns the kit’s Upper object;
Ravel.lower(): returns the kit’s Lower object;
Ravel.displayRingGauges(): displays a gauge on the LCD showing the RGB values of each LED in the ring; requires a prior call to LCD.uploadUpwardGaugeChars().

Constants#

SERVO_MAX: maximum value for the position of the Upper and Lower servos;
RING_MAX: maximum value for each color (R, G, and B) of the Ring LEDs;
RING_SIZE: number of LEDs in the ring;
OLED_WIDTH: number of horizontal pixels on the OLED screen;
OLED_HEIGHT: number of vertical pixels on the OLED screen;
LCD_WIDTH: number of characters per line on the LCD display;
LCD_HEIGHT: number of lines on the LCD display.

Building the Ravel kit

Mon, 01 Jan 0001 00:00:00 +0000

Building the Ravel Kit#

NOTE: click on a photo to view an enlarged version.

Overview of Components#

A photo showing almost all the components in the kit. The only ones missing are those related to the servos.

The Microcontroller#

The microcontroller is an ESP32-C3 SuperMini.

The Buzzer#

The buzzer is a passive buzzer, meaning you can adjust the frequency of the sound it emits, unlike an active buzzer. It is driven by a PWM signal. Additionally, you can influence the pitch and volume of the sound to some extent by adjusting the PWM signal ratio.