Bootstrap
Ok, so you're ready for some robot code. Here is a bootstrap, the minimum you need to talk to the controller app. Don't worry if it looks a little daunting. You just need to copy this to a file on your robot and run it. Of course it won't make it do anything, it will just print out the data it gets to the console. It is written in CPython.
#!/usr/bin/env python3
import socket
import random
import os
hostName = socket.gethostname()
hostIPA = socket.gethostbyname(hostName)
print("hostIP",hostIPA)
port = random.randint(50000,50999)
os.system('setfont Lat15-TerminusBold32x16')
print("host",hostIPA)
print("port",port)
online = True
backlog = 1
size = 1024
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((hostIPA,port))
s.listen(backlog)
try:
client, address = s.accept()
while online:
data = client.recv(size)
decoded = data.decode('utf-8')
if decoded:
print("data",decoded)
except AssertionError as error:
print("Closing app socket",error)
client.close()
s.close()
exit()
Bootstrap II
Here is another bootstrap. It is the same thing, but written in MicroPython this time. It looks a little different cause I needed different code to get the IP address and I added a special method to display the port number using images since it is not possible to change the tiny text size with MicroPython. The images I used are display in a line next to the code.
#!/usr/bin/env pybricks-micropython
from pybricks import ev3brick as brick
from time import sleep
import time
import random
import socket
import os
​
hostname = os.popen('hostname -I').read().strip().split(" ")
print("hostname address",hostname[0])
hostIPA = hostname[0]
millis = int(round(time.time()))
print(millis)
random.seed(millis)
port = random.randint(50000,50999)
brick.display.clear()
brick.sound.beep(2)
def bigText(No):
xCord = 25
portText = str(port)
for figure in range(len(portText)):
no = portText[figure:figure+1]
no2display = "/home/robot/robot/No" + no + ".png"
brick.display.image(no2display,(xCord,0),clear=False)
xCord = xCord + 25
online = True
bigText(port)
sleep(12)
brick.sound.beep(4)
ai = socket.getaddrinfo(hostIPA,port)
addr = ai[0][-1]
backlog = 5
size = 1024
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(addr)
s.listen(backlog)
try:
res = s.accept()
while online:
client_s = res[0]
#client_addr = res[1]
data = client_s.recv(1024)
decoded = data.decode('utf-8')
if decoded:
print("data",decoded)
except AssertionError as error:
print("Closing socket",error)
client_s.close()
s.close()
