I have been having a lot of fun with my Beaglebone Black now that wifi is up and running smoothly (can't believe it took so long to get a good adapter!). One of the most recent acquisitions was a Bosche BME280 sensor - tiny, with readouts of temperature, barometric pressure, and humidity - i guess smartphones are getting smarter?
Well, thankfully I didn't have to shell out an outrageous amount of dinero for this sensor. You can get 'em for less than a Hamilton on-line, so I popped for a pair. I used Matt Hawkin's excellent bme280.py script as an accessible Python lib (simply drop it in the same folder as your script), and just used the function to get the data:
from bme280 import readBME280All
the original script returns many digit accuracy - too many for the oled, so i trimmed the output, converted from Centigrade to Fahrenheit and hectopascals to inches of mercury:
return "%.2f degrees F" % (((temperature)*9/5)+32)return "%.2f inches mercury" % ((pressure)/33.8638866667)return "%.2f%% humidity" % humidity
#!/usr/bin/env python
# bbssd.py version 0.6 - a simple system monitor for the
# Beaglebone Black GNU/Linux SBC
# kg4zqz.blogspot.com
# adapted from rmhull's wonderful ssd1306 Python lib
# crafted for the dual-color 128x96 OLED w/yellow top area
# 070916 - initial version ported from a version for the Raspberry Pi
# shows date, wlan0 IP address, memory, and sd card usage
# 070916 - added Beagle splash screen, kernel version and serial #
# 071016 - added uptime, wifi sig strength, screen cleanup
# 072616 - added text wrap to uptime screen
# 081416 - added BME280 weather sensor data/readout
#
# note: it was a bear to get all the needed software libs for
# the Pillow install - must have libjpeg6-dev and associated zlib pkgs!
import os
import psutil
from lib_oled96 import ssd1306
from time import sleep
from datetime import datetime
from PIL import ImageFont, ImageDraw, Image
from smbus import SMBus # These are the only two variant lines !!
i2cbus = SMBus(2) # NOTE: Beaglebone Green Wireless uses bus 2!
oled = ssd1306(i2cbus)
draw = oled.canvas
while True:
# "draw" onto this canvas, then call display() to show on the OLED.
draw = oled.canvas
# show SPLASH screen
# set font to 17 for yellow area splash title
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), 'BEAGLEBONE', font=font, fill=1)
# put on the dawg, which is capital 'S' in the below font
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/Doggon.ttf', 50)
draw.text((1, 23), ' S', font=font, fill=1)
# now show splash screen, then sleep, then clear for next screen
oled.display()
sleep(3)
oled.cls()
# set up, display overall stats screen
# set font to 13 for yellow area
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 13)
# get, display date and time
draw.text((1, 1), str(datetime.now().strftime('%a %b %d %H:%M:%S')), font=font, fill=1)
# reset font for four smaller lines
font = ImageFont.truetype('FreeSans.ttf', 10)
# get, return Linux kernel version
def uname_r():
k = os.popen('uname -r')
rev = str(k.read())
# strip out trailing chars for cleaner output
return "KERNEL: %s" % rev.rstrip('\r\n')
# display kernel version
draw.text((1, 15), uname_r(), font=font, fill=1)
# get, return wlan0's current IP address
def wlan_ip():
f = os.popen('ifconfig wlan0 | grep "inet\ addr" | cut -c 21-33')
ip = str(f.read())
# strip out trailing chars for cleaner output
return "WIFI IP: %s" % ip.rstrip('\r\n')
# display the IP address
draw.text((1, 28), wlan_ip(), font=font, fill=1)
# get amount of free memory
def mem_usage():
usage = psutil.virtual_memory()
return "MEM USED: %s KB" % (int(str(usage.used)) / 1024)
# display amount of free memory
draw.text((1, 41), mem_usage(), font=font, fill=1)
# get disk usage
def disk_usage(dir):
usage = psutil.disk_usage(dir)
return "SD CARD USED: %.0f%%" % (usage.percent)
# display disk usage
draw.text((1, 53), disk_usage('/'), font=font, fill=1)
# now show the entire stats screen, then clear
oled.display()
sleep(5)
oled.cls()
# read bme280 data - limit 2-digit accuracy
def get_temp():
from bme280 import readBME280All
temperature,pressure,humidity = readBME280All()
# return "%sF" % str(((temperature)*9/5)+32)
return "%.2f degrees F" % (((temperature)*9/5)+32)
def get_pressure():
from bme280 import readBME280All
temperature,pressure,humidity = readBME280All()
# return "%s hPa" % str(pressure)
return "%.2f inches mercury" % ((pressure)/33.8638866667)
def get_humidity():
from bme280 import readBME280All
temperature,pressure,humidity = readBME280All()
# return "%s percent" % str(humidity)
return "%.2f%% humidity" % humidity
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 13)
draw.text((1, 1), 'Ambient Conditions', font=font, fill=1)
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 12)
draw.text((1, 20), get_temp(), font=font, fill=1)
draw.text((1, 35), get_pressure(), font=font, fill=1)
draw.text((1, 50), get_humidity(), font=font, fill=1)
oled.display()
sleep(5)
oled.cls()
# begin series of LARGE stats
# LARGE display - get wifi wlan0 signal strength
def get_wifi():
cmd = "iwconfig wlan0 | grep Signal | /usr/bin/awk '{print $4}' | /usr/bin/cut -d'=' -f2"
strDbm = os.popen(cmd).read()
dbm = int(strDbm)
quality = 2 * (dbm + 100)
if strDbm:
return("{0} dbm = {1}%".format(dbm, quality))
else:
return("No Wifi")
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), 'WIFI SIGNAL', font=font, fill=1)
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 15)
draw.text((1, 30), get_wifi(), font=font, fill=1)
oled.display()
sleep(3)
oled.cls()
# LARGE display - uptime
def get_uptime():
uptime = os.popen("uptime")
ut = str(uptime.read())
# strip out trailing chars for cleaner output
return "%s" % ut.rstrip('\r\n')
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), ' UPTIME', font=font, fill=1)
# now smaller font needed and wrap text to show info
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 11)
import textwrap
lines = textwrap.wrap(get_uptime(), width=25)
# what 'line' to start info
y_text = 20
w = 1 # we'll always start at left side of OLED
for line in lines:
width, height = font.getsize(line)
draw.text((w, y_text), line, font=font, fill=1)
y_text += height
oled.display()
sleep(4)
oled.cls()
# LARGE display - wlan0's IP address
def wlan_lip():
f = os.popen('ifconfig wlan0 | grep "inet\ addr" | cut -c 21-33')
ip = str(f.read())
# strip out trailing chars for cleaner output
return "%s" % ip.rstrip('\r\n')
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), ' IP ADDRESS', font=font, fill=1)
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 16)
draw.text((1, 30), wlan_lip(), font=font, fill=1)
oled.display()
sleep(3)
oled.cls()
# LARGE display - amount of free memory
def mem_usagel():
usage = psutil.virtual_memory()
return "%s KB" % (int(str(usage.used)) / 1024)
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), 'MEM USED', font=font, fill=1)
draw.text((1, 30), mem_usagel(), font=font, fill=1)
oled.display()
sleep(3)
oled.cls()
# LARGE display - Beaglebone's serial number
def get_serial():
serial = os.popen('/usr/local/bin/get_serial_no')
snum = str(serial.read())
# strip out trailing chars for cleaner output
return "%s" % snum.rstrip('\r\n')
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 17)
draw.text((1, 1), 'SERIAL NBR', font=font, fill=1)
# now smaller font needed
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 15)
draw.text((1, 30), get_serial(), font=font, fill=1)
oled.display()
sleep(3)
oled.cls()
# get, return current local WX
def do_wx():
f = os.popen('/usr/local/bin/currentwx')
wx = str(f.read())
# strip out trailing chars for cleaner output
return "%s" % wx.rstrip('\r\n')
# display the WX
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 13)
draw.text((1, 1), 'CURRENT WEATHER:', font=font, fill=1)
font = ImageFont.truetype('/home/debian/Downloads/ssd1306-master/FreeSans.ttf', 12)
draw.text((1, 15), ' PINELLAS PARK, FL', font=font, fill=1)
draw.text((1, 41), do_wx(), font=font, fill=1)
oled.display()
sleep(3)
oled.cls() # Oled still on, but screen contents now blacked out
No comments:
Post a Comment