NodeMCU Config
Micropython
Basics
- Installing:
sudo pip install esptool esptool.py --port /dev/ttyUSB0 erase_flash esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 ~/Desktop/esp8266-20171101-v1.9.3.bin
- Check the firmware integrity:
import esp esp.check_fw()
- Connecting via Terminal:
sudo apt install picocom picocom /dev/ttyUSB0 -b115200
- Connecting via REPL(web):
import webrepl_setup
If you disabled automatic start-up on boot, you may run configured daemon on demand using:
import webrepl webrepl.start()
- Checking filesystem:
import os os.listdir()
- Create directories:
os.mkdir('dir')
- Remove Files:
os.remove('data.txt')
- Writing Data to files:
f = open('data.txt', 'w') f.write('some data') f.close()
- Reading data:
f = open('data.txt') f.read() f.close()
- Checking Machine Frequency & Overclocking:
import machine machine.freq() # get the current frequency of the CPU machine.freq(160000000) # set the CPU frequency to 160 MHz
- Check AP Name:
import network ap = network.WLAN(network.AP_IF) print(ap.config('essid'))
- Change AP name and password:
import network ap = network.WLAN(network.AP_IF) ap.active(True) ap.config(essid='MyESP8266', authmode=network.AUTH_WPA_WPA2_PSK, password='mypassword') print(ap.config('essid'))
- Boot Process:
As a final step of boot procedure, main.py is executed from filesystem This file is a hook to start up a user application each time on boot (instead of going to REPL). For small test applications, you may name them directly as main.py but instead it’s recommended to keep your application(s) in separate files, and have just the following in main.py:
import my_app my_app.main()
- Upload data using Serial Port
sudo pip install adafruit-ampy ampy --port /dev/ttyUSB0 put ~/Desktop/main.py
Deep-sleep mode
- This shut down the ESP8266 and all its peripherals & also WiFi.
- But not including the real-time-clock, which is used to wake the chip.
- This drastically reduces current consumption and is a good way to make devices that can run for a while on a battery.
- You Must connect GPIO16 to the reset pin.
import machine
# configure RTC.ALARM0 to be able to wake the device
rtc = machine.RTC()
rtc.irq(trigger=rtc.ALARM0, wake=machine.DEEPSLEEP)
# check if the device woke from a deep sleep
if machine.reset_cause() == machine.DEEPSLEEP_RESET:
print('woke from a deep sleep')
# set RTC.ALARM0 to fire after 10 seconds (waking the device)
rtc.alarm(rtc.ALARM0, 10000)
# put the device to sleep
machine.deepsleep()
Code Snipets
Playing with GPIO
import machine
import time
import urandom
pin = machine.Pin(2, machine.Pin.OUT)
def toggle(p):
p.value(not p.value())
while True:
time.sleep_ms(urandom.getrandbits(8))
toggle(pin)
Fading an LED
import time, math
import machine
led = machine.PWM(machine.Pin(2), freq=1000)
def pulse(l, t):
for i in range(20):
l.duty(int(math.sin(i / 10 * math.pi) * 500 + 500))
time.sleep_ms(t)
while True:
pulse(led, 20)
Control a hobby servo
Hobby servo motors can be controlled using PWM. They require a frequency of 50Hz and a duty between about 40 and 115, with 77 being the center value.
- Manual Movements
servo = machine.PWM(machine.Pin(12), freq=50)
servo.duty(40)
servo.duty(115)
servo.duty(77)
- Random movements:
servo = machine.PWM(machine.Pin(12), freq=50)
while True:
servo.duty(urandom.getrandbits(8))
time.sleep(1)
One Wire DS18B20 Temp Sensor
import time
import machine
import onewire, ds18x20
# the device is on GPIO12
dat = machine.Pin(12)
# create the onewire object
ds = ds18x20.DS18X20(onewire.OneWire(dat))
# scan for devices on the bus
roms = ds.scan()
print('found devices:', roms)
# loop 10 times and print all temperatures
for i in range(10):
print('temperatures:', end=' ')
ds.convert_temp()
time.sleep_ms(750)
for rom in roms:
print(ds.read_temp(rom), end=' ')
print()
- References
{{#widget:DISQUS
|id=networkm
|uniqid=NodeMCU Config
|url=https://aman.awiki.org/wiki/NodeMCU_Config
}}