The script in question displays the IP address of a raspberry pi, and a voltage that the raspberry pi is reading from an i2c bus, on an i2c OLED screen. Same as with the other tutorial, https://www.linuxshelltips.com/run-python-script-ubuntu-startup/ it was placed in /bin, I put the same permissions, same owner, and both were placed in the non-sudo crontab. Logically, there must be something about the script that makes a run on boot not work, despite it working when when I write "python3 display_battery*_*IP.py" in terminal. Any help would be greatly appreciated.
This is my first time posting on stakcoverflow, so my apologies if this is messy, the code has a bunch of comments because I first need to get it running properly without the additional functions:
import readline
from telnetlib import IP
import time
import Adafruit_GPIO.SPI as SPI
import Adafruit_SSD1306
from std_msgs.msg import String
from std_msgs.msg import Float32
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
import rospy
import re
import subprocess
import smbus
# Raspberry Pi pin configuration:
RST = None # on the PiOLED this pin isnt used
# Note the following are only used with SPI:
DC = 23
SPI_PORT = 0
SPI_DEVICE = 0
# Beaglebone Black pin configuration:
# RST = 'P9_12'
# Note the following are only used with SPI:
# DC = 'P9_15'
# SPI_PORT = 1
# SPI_DEVICE = 0
# 128x32 display with hardware I2C:
disp = Adafruit_SSD1306.SSD1306_128_32(rst=None, i2c_bus=1, gpio=1)
bus = smbus.SMBus(1)
# Initialize library.
disp.begin()
disp.clear()
disp.display()
# Create blank image for drawing.
# Make sure to create image with mode '1' for 1-bit color.
width = disp.width
height = disp.height
image = Image.new('1', (width, height))
# Get drawing object to draw on image.
draw = ImageDraw.Draw(image)
# Draw a black filled box to clear the image.
draw.rectangle((0,0,width,height), outline=0, fill=0)
# Draw some shapes.
# First define some constants to allow easy resizing of shapes.
padding = -2
top = padding
bottom = height-padding
# Move left to right keeping track of the current x position for drawing shapes.
x = 0
# Load default font.
font = ImageFont.load_default()
IP_prev = 'No IP'
IP_filt = ''
# ro red voltage and current from Arduino Nano through I2C
# for code on the arduino:
nano_addr = 12 # I2C adress of nano (setted in software!)
voltage_reg_nano = 0 # value to send to arduino to get voltage read back
# Calibration values for converting from raw digital binary form to decimal form
# Calibration values were manualy calibrated to +- 0.1V acuracy!
calVoltageA = 11
calVoltageB = 0.0
calCurrent = 37.8788
calCurrentOffset = 0.33
# init of I2C bus with arduino nano conected
bus = smbus.SMBus(1)
xavier_IP = ""
system_voltage = 0
system_current = 0
func = 1
def func_check(func):
if func == 1:
draw.text((x, top+16), "Wellness: 1 ", font=font, fill=255)
return 0
else:
draw.text((x, top+16), "Xavier: 0", font=font, fill=255)
return 1
def read_voltage():
# Sometimes an I/O timeout or error happens, it will run again when the error disappears
try:
# arduino is configure to send voltage data on "register" 0, current on 1
# data is sent in 2 bytes, because to big for one I2C message
voltage_msg = bus.read_i2c_block_data(nano_addr, 0, 2)
# conversion to get real voltage
# measurement up to 1023, so to big for 7bit I2C messages. Sends MSB first, then LSB, then remap to 0-5V
x = (((voltage_msg[0]&0x7) << 7) + voltage_msg[1]) * 5/1023.0
system_voltage = x * calVoltageA + calVoltageB
#####################################################################################################################
#voltage_msg = bus.read_i2c_block_data(nano_addr, 0, 2)
# conversion to get real voltage
# measurement up to 1023, so to big for 7bit I2C messages. Sends MSB first, then LSB
#system_voltage = float((((voltage_msg[0]&0x7) << 7) + voltage_msg[1])) * calVoltageA + calVoltageB
#####################################################################################################################
#print("Gone through loop")
#print(system_voltage)
return system_voltage
except IOError:
print("Bus IOerror")
return 0
def read_current():
try:
current_msg = bus.read_i2c_block_data(nano_addr, 1, 2)
# conversion to get real voltage
x = float((((current_msg[0]&0x7) << 7) + current_msg[1])) * 5 / 1023.0
system_current = (x - calCurrentOffset) * calCurrent
#rospy.loginfo(f"Current : {self.system_current}A")
except IOError:
print("BUS error")
while True:
cmd = "ip -4 -o address show dev eth0 | awk '{print $4}'"
# Draw a black filled box to clear the image.
IP_bytes = subprocess.check_output(cmd, shell = True )
IP_str = IP_bytes.decode('utf-8')
IP_str.split('/')
#print(IP_str)
draw.rectangle((0,0,width,height), outline=0, fill=0)
#with open("xavier_IP.txt", "r") as f:
# xavier_IP = f.readlines()
voltage_str = str(round(read_voltage(), 1))
#print(voltage_str)
#read_current()
func = func_check(func)
# Shell scripts for system monitoring from here : https://unix.stackexchange.com/questions/119126/command-to-display-memory-usage-disk-usage-and-cpu-load
# Write two lines of text.
draw.text((x, top), "IP: " + IP_str, font=font, fill=255)
draw.text((x, top+8), "Voltage: "+ voltage_str, font=font, fill=255)
#draw.text((x, top+16), "Xavier: "+ xavier_IP, font=font, fill=255)
# Display image.
disp.image(image)
disp.display()
time.sleep(1)
Another script with the exact same OLED display setup worked on boot just fine, the difference here is the reading of voltage through the i2c bus and the display of it on the OLED, so I highly doubt the issue is related to the OLED part of the question itself. I have tried changing the permissions and ownership of the script, I have both done sudo crontab -e, and non-sudo. Before I put the script in /bin, I made a directory called ./bootscripts and attempted to make a cronjob using that placement (I am a big newbie, so I thought it might make a difference for all I know).
