This is code to run the LEDs in an infinity mirror while running on a Raspberry Pi Pico-W. It also contains a simulator for creating new display modes.
The main files are as follows
mirror.py- the main code to run on the picomodes/- a directory of "modes" for the mirror - edit__init__.pyto add new onesREADME.md- this filerp2mirror_boot- set the pico to boot the coderp2mirror_run- send the code to the picorp2run- run a bit of code on the picosecrets.py- contains WiFi access for the pico - not checked insim.py- the simulator - run this to test the modes on your computer
Note that secrets.py should have your WiFi access details for use by the pico only.
SSID = "yourssid"
PASSWORD = "your password"The infinity mirror has a half silvered mirror and a fully silvered mirror about 3 cm apart. Around the edge of that gap there are 34 neopixels controlled by the pico. The pico also has three analogue potentiometers (knobs) which have the function:
- Brightness
- Hue
- Speed
These can be interpreted by the running mode however its wants, but it
should try to obey the Brightness knob so as not to suprise the
user.
There are two buttons also, mode forward and mode backwards.
The current installed modes are
colour_temp_lights- all lights on at an adjustable colour temperaturehsv_lights- all lights on with an adjustable Hue, Saturation and Valuehsvwaves- waves of HSV around the lightsled_test- turns one LED on at a timesoftglow- soft RGB glowhsv_spin- spinning Hue with controllable saturation and speedchristmas- red and green christmassy lightstemperature- shows the temperature. Number of on LEDs is temp in C with flashing showing partial.time- shows analogue time with 3 LEDS - Red is Hours, Green is Mins, Blue is Seconds
First make sure you have pygame installed.
Then run python3 sim.py to run the simulator.
You can control the simulator with the mouse
- Click LEFT, RIGHT to change mode
- Mouse wheel to change brightness (knob 0)
- SHIFT mouse wheel for hue (knob 1)
- CTRL mouse wheel for speed (knob 2)
- SHIFT+CTRL mouse wheel for temperature
To write a new mode, copy and rename one of the existing ones and add
it to modes/__init.py in the order that you want it.
Note that the modes run under both python3 and micropython so a little care is needed. Test first with the simulator.
Each mode should have this structure:
class Mode:
NAME = "Name of your mode - printed to the serial console"
def __init__(self, mirror):
self.mirror = mirror
# more stuff
def update(self):
"""
Update mirror with the current state
This is called 25 times per second.
"""
# Plot your mode on the LEDs hereThe mode is passed in a mirror object which has the following
methods you can use. This is a different object when running under
micropython or the simulator, but python's duck typing takes care of
it.
class Mirror:
def __setitem__(self, index, value):
"""
We use mirror[0] = color to set colours
"""
def __getitem__(self, index):
"""
Read the value set by __setitem__
"""
def fill(self, col):
"""
Set all the LEDs to col
"""
def local_time(self):
"""
Returns the broken down local time like time.localtime()
"""
def knob(self, i):
"""
Read the ADC as a floating point number 0..1
"""
def knob_brightness(self):
"""
Brightness knob as a floating point number 0..1
"""
def knob_hue(self):
"""
Hue knob as a floating point number 0..1
"""
def knob_speed(self):
"""
Speed knob as a floating point number 0..1
"""
def temperature(self):
"""
Return the temperature of the board in C as a floating point number
"""The Mirror object also has an attribute n which is the number of LEDs.
Note that colours are specified as tuples (red, green, blue) and the
range should be from 0..255 for each value.
Here is a collection of notes made while building the project.
Install micropython firmware from here
https://www.raspberrypi.com/documentation/microcontrollers/micropython.html
Note using Pico W version rp2-pico-w-20230116-unstable-v1.19.1-803-g1583c1f67.uf2
rshell to communicate with Pico W and send / receive files.
sudo apt install python3-rshell
Could also use Thonny.
rshell - can cp things to /pyboard
Use repl then type
import machine
led = machine.Pin("LED", machine.Pin.OUT)
led.off()
led.on()
Micropython quick start docs are here: https://docs.micropython.org/en/latest/rp2/quickref.html
RP2 micropython comes with built in neopixel library
This should set the LED to a pink color
from neopixel import NeoPixel
import machine
pin = machine.Pin(0)
pixels = NeoPixel(pin, 1)
pixels.fill((255, 5, 20))
pixels.write()
The ordering of RGB seems to be wrong - this is easily fixed with
NeoPixel.ORDER = (0, 1, 2, 3)
So
from neopixel import NeoPixel
NeoPixel.ORDER = (0, 1, 2, 3)
import machine
pin = machine.Pin(0)
pixels = NeoPixel(pin, 1)
pixels.fill((255, 5, 20))
pixels.write()
To start a python program at boot copy it as main.py using rshell
home/ncw> cp /pyboard/softglow.py /pyboard/main.py
Copying '/pyboard/softglow.py' to '/pyboard/main.py' ...
The pico will now run this program on powerup and rshell will no longer work.
If rshell is not working because a main.py has been installed.
Use
picocom /dev/ttyACM0 -b115200
Then press CTRL-C until you see
Traceback (most recent call last):
File "main.py", line 27, in <module>
KeyboardInterrupt:
MicroPython v1.19.1-803-g1583c1f67 on 2023-01-16; Raspberry Pi Pico W with RP2040
Type "help()" for more information.
>>>
Then type this to remove the main.py
import os
os.listdir("/")
os.remove("main.py")
Then enter CTRL-d to soft reset the pico.
CTRL-a CTRL-x to exit picocom
rshell should work again.
Can use rshell interactively, but it can be scripted also
rshell --quiet cp softglow2.py /pyboard/softglow2.py
rshell --quiet "repl ~ exec(open('softglow2.py').read())"
This is embodied in the rp2run script.
From the data sheet
VBUS is the 5V input from the micro-USB port, which is fed through a Schottky diode to generate VSYS. The VBUS to VSYS diode (D1) adds flexibility by allowing power ORing of different supplies into VSYS.
and later
The simplest way to safely add a second power source to Pico is to feed it into VSYS via another Schottky diode (see Figure 15). This will 'OR' the two voltages, allowing the higher of either the external voltage or VBUS to power VSYS, with the diodes preventing either supply from back-powering the other.
We will run the LEDs directly from an external 5V power supply. Since the RP SYS input range is 1.8V to 5.5V we don't need to worry about a diode drop, so any silicon diode should be fine.
- So via a diode connect external 5V PSU to VSYS
- Leave VBUS unconnected (since it connects directly to the USB power)
This will allow us to connect a computer and not blow up the computer with the external 5V PSU.
You will need to make a file called secrets.py to make the WLAN work
with the contents:
SSID = "your access point SSID"
PASSWORD = "you access point password"
This file isn't checked in to the repo and is in .gitignore.
The Board and LEDs take 1.22A with them all white on at maximum brightness. With all the LEDs off the current draw is 30 mA. So each LED is taking 35 mA maximum with the board taking 30 mA. Measured with a 20A multimeter inline.
| Activity | Amps |
|---|---|
| LEDs off | 0.03 |
| Time | 0.07 |
| Temp | 0.40 |
| Christmas | 0.30 |
| HSV Spin | 0.60 |
| All white | 1.22 |
The data sheet says
Default output constant current value 12mA, high constant current accuracy, easy to reduce the power consumption of built-in lamp beads
Which aparently means 12mA per LED colour (Red, Green or blue) for a total of 36 mA which agrees pretty well with the measured 35 mA.
This 12 mA per colour is quite obvious in a later table in the datasheet (headings translated from Chinese).
| Luminous Color | Dominant Wavelength (nm) | Luminous Intensity (mcd) | Working Current (mA) | Working Voltage (V) |
|---|---|---|---|---|
| R | 620-630 | 600- 800 | 12 | 2.0-2.2 |
| G | 515-525 | 1300-2000 | 12 | 3.0-3.3 |
| B | 460-470 | 400- 500 | 12 | 3.0-3.3 |
