This is a small program showing the API.
Note: pins that are set as inputs are pulled up.
#!/usr/bin/python3
# In this example the LED on the NodeMCU board can be toggled
# by a button connecting D1 to GND.
from nodemcu import NodeMcu, NodeMcuError, D
from time import sleep
from sys import exit
from common import getIPPort
try:
mcu = NodeMcu(getIPPort())
mcu.setOutput(D[0])
mcu.setInput(D[1])
print("Press button on D1 to toggle LED")
bit = False
changeOk = True
while True:
mcu.write(D[0], bit)
n = mcu.read(D[1])
# when the button is pressed n == False
if n == False and changeOk:
# only toggle the led when the button has been released since the last change
bit = not bit
changeOk = False
elif n == True:
# when the button is released, allow the user to toggle the LED again
changeOk = True
except NodeMcuError as e:
print("error:", e)The truth values True and False are used to describe HIGH and LOW states, respectively.
$ cd client
$ python3 example_test_pins.py 192.168.x.y
Measure the pins with a multimeter or wire LEDs to them.
$ cd client
$ python3 example_blink_led.py 192.168.x.y
$ cd client
$ python3 example_led_button.py 192.168.x.y
Pressing the button turns the LED off if turned on and vice-versa.
$ cd client
$ python3 example_7seg_display.py 192.168.x.y
This example needs a bit more complex wiring. It also uses a 74HC595 shift register. The image below shows the display counting from 0 to 9. Unfortunately, one of the segments was not properly connected by the breadboard.
