NodeMCU Projects: Difference between revisions
→Analog Temperature Meter
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__TOC__
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= Small Projects =
== Playing with GPIO ==
<syntaxhighlight lang="python">
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)
</syntaxhighlight>
== Fading an LED ==
<syntaxhighlight lang="python">
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)
</syntaxhighlight>
== 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
<syntaxhighlight lang="python">
servo = machine.PWM(machine.Pin(12), freq=50)
servo.duty(40)
servo.duty(115)
servo.duty(77)
</syntaxhighlight>
*Random movements:
<syntaxhighlight lang="python">
servo = machine.PWM(machine.Pin(12), freq=50)
while True:
servo.duty(urandom.getrandbits(8))
time.sleep(1)
</syntaxhighlight>
== One Wire DS18B20 Temp Sensor ==
<syntaxhighlight lang="python">
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()
</syntaxhighlight>
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