Fitra - Arc Reactor using ESP32 and Web of Things

Requirements

Requirement tools:

• SparkFun ESP32 Thing
• Jumper Male-Male 20cm
• Battery Lipo 3.7v 1000mAh
• Rainbow LED WS2812
• Solder
• Solder Iron

HOW TO

Datasheet and Soldering

The following datasheet is advised by my friend from SurabayaPy Tegar Imansyah

Connect SparkFun and Rainbow LED WS2812 with jumper by using the following schema

SparkFun	Jumper	LED WS2812
13	Connect to	DIN
VBAT/VUSB	Connect to	VCC
GND	Connect to	GND

Use VBAT for battery power and VUSB for USB power

Flashing Loboris Micropython

Clone the fork of Loboris Micropython repository, this repository has been updated to allow PUT command to work with microWebSrv and fix for microWebSocket based on this branch and latest update from Loboris master branch

$ git clone https://github.com/ariestiyansyah/MicroPython_ESP32_psRAM_LoBo.git

Config the micropython and build the Firmware

$ cd MicroPython_ESP32_psRAM_LoBo/MicroPython_BUILD/
$ ./BUILD.sh menuconfig
$ ./BUILD.sh

Flash it

$ ./BUILD.sh --port /dev/tty.usbserial-DN03F9EP flash

SparkFun connected to my mac using /dev/tty.usbserial-DN03F9EP port, this will be different on each device, check it using following command

$ ls /dev/tty.usbserial*

Install Gateway

Follow instruction from https://github.com/mozilla-iot/gateway/blob/master/README.md to install Mozilla Gateway in your Raspberry Pi or PC/Mac.

Web of Things Micropython

Clone fitra project

$ git clone https://github.com/ariestiyansyah/fitra.git

Hierarchy of fitra project

.
├── README.md
├── config.py
├── connect.py
├── main.py
├── src
│   ├── neopixel
│   │   ├── np.py
│   ├── upy
│   │   ├── README.md
│   │   ├── copy.py
│   │   ├── eventemitter.py
│   │   ├── logging.py
│   │   ├── types.py
│   │   └── uuid.py
│   └── webthing
│       ├── action.py
│       ├── event.py
│       ├── property.py
│       ├── server.py
│       ├── thing.py
│       ├── utils.py
│       └── value.py
├── start.py
└── webserver.py

Rename file config.example.py to config.py, change variable SSID and PASSWORD value with wifi credentials, for example

SSID = 'FITRA'
PASSWORD = 'bahagialah'

Sync local files to ESP32 by using rshell, you can also use ampy :) mine is rhsell.

$ rshell -a --buffer-size=30 -p /dev/tty.usbserial-DN03F9EP
fitra> rsync -v . /flash
fitra> repl
>>> Control-D # Soft reset

You will see spining LED in neopixel now.

Adding RGB function and Property

Create sample display_odd function to display LED in odd number by

# src/neopixel/np.py
def display_odd(np, delay=DELAY, color=COLOR, saturation=SATURATION, brightness=BRIGHTNESS, clear=True):
    for reactor in REACTORS:
        if reactor % 2 == 1:
            continue
        np.setHSB(reactor, color, saturation, brightness, 1, False)
        np.show()
        time.sleep_ms(delay)
    if clear:
        np.clear()

Add property to enable it in gateway

# webserver.py
self.add_property(
	Property(self,
		'odd',
		Value(self.odd, self.oddReactor),
		metadata={
			'@type': 'OnOffProperty',
			'label': 'Display Odd Reactor',
			'type': 'boolean',
			'description': 'Turn on the Reactor',
		}))

Convert RGB to Hex

This function contributed by my partner in crime Ady Rahmat MA

# webserver.py
def convertToRgb(self, color):
    red = int(color[1:3], 16) / 256 * 100
	green = int(color[3:5], 16) / 256 * 100
	blue = int(color[5:7], 16) / 256 * 100
	return (red, green, blue)

def convertToHex(self, color):
    return int(hex(int(color[1:], 16)), 16)
    hex_color = self.convertToHex(self.color)
    hue, saturation, brightness = self.np.RGBtoHSB(hex_color)

Lesson Learned

all problems found during the experiment.

LED on USB power vs Battery power

The led does not run normally when connected with USB Power, it will run smoothly on battery power.

Could not enter raw repl

rshell -a --buffer-size=30 -p /dev/tty.usbserial-DN03F9EP                              [19:09:48]
Connecting to /dev/tty.usbserial-DN03F9EP ...
b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x9as' [size: 2555904; Flash address: 0x190000]\r\n----------------\r\nFilesystem size: 2341888 B\r\n           Used: 142080 B\r\n           Free: 2199808 B\r\n----------------\r\n"
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1186, in connect
    ip_address = socket.gethostbyname(port)
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/rshell", line 11, in <module>
    load_entry_point('rshell==0.0.14', 'console_scripts', 'rshell')()
  File "/usr/local/lib/python3.7/site-packages/rshell/command_line.py", line 4, in main
    rshell.main.main()
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 2712, in main
    real_main()
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 2674, in real_main
    connect(args.port, baud=args.baud, wait=args.wait, user=args.user, password=args.password)
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1192, in connect
    connect_serial(port, baud=baud, wait=wait)
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1216, in connect_serial
    dev = DeviceSerial(port, baud, wait)
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1462, in __init__
    Device.__init__(self, pyb)
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1269, in __init__
    elif not self.remote_eval(test_unhexlify):
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1379, in remote_eval
    return eval(self.remote(func, *args, **kwargs))
  File "/usr/local/lib/python3.7/site-packages/rshell/main.py", line 1357, in remote
    self.pyb.enter_raw_repl()
  File "/usr/local/lib/python3.7/site-packages/rshell/pyboard.py", line 187, in enter_raw_repl
    raise PyboardError('could not enter raw repl')
rshell.pyboard.PyboardError: could not enter raw repl

CPU Halted, lol

/Users/ariestiyansyah/code/research/github/ariestiyansyah/esp32/fitra> repl
Entering REPL. Use Control-X to exit.
repl_serial_to_stdout dev = <rshell.main.DeviceSerial object at 0x102a58cc0>
>
MicroPython ESP32_LoBo_v3.2.24 - 2018-09-06 on ESP32 Rizky with ESP32
Type "help()" for more information.
>>>
>>> import machine
>>> np = machine.Neopixel(machine.Pin(13), 24)
>>> np.deinit()
>>> np = machine.Neopixel(machine.Pin(13), 24)
Guru Meditation Error: Core  1 panic'ed (LoadProhibited). Exception was unhandled.
Core 1 register dump:
PC      : 0x400e0027  PS      : 0x00060031  A0      : 0x800e01a8  A1      : 0x3ffb1fb0
A2      : 0x00000018  A3      : 0x00000000  A4      : 0x00000000  A5      : 0x00000000
A6      : 0x00000000  A7      : 0x00000004  A8      : 0x0ffd114c  A9      : 0x00000000
A10     : 0x00000009  A11     : 0x00000000  A12     : 0x00002000  A13     : 0x3ff44024
A14     : 0x00000000  A15     : 0x00060923  SAR     : 0x0000000b  EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000018  LBEG    : 0x4000c28c  LEND    : 0x4000c296  LCOUNT  : 0x00000000
Core 1 was running in ISR context:
EPC1    : 0x400e0027  EPC2    : 0x00000000  EPC3    : 0x00000000  EPC4    : 0x40083410

Backtrace: 0x400e0027:0x3ffb1fb0 0x400e01a5:0x3ffb1fe0 0x40082779:0x3ffb2010 0x400e03ef:0x00000000

CPU halted.

serial port pyboard closed