net.py

import subprocess
import time
import Adafruit_GPIO.SPI as SPI
import Adafruit_SSD1306
import Image
import ImageDraw
import ImageFont

# Raspberry Pi pin configuration:
RST = 24

# 128x64 display with hardware I2C:
disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST)

# Initialize library.
disp.begin()

# Clear display.
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)

# Load default font.
font = ImageFont.load_default()

#Display Image
disp.image(image)
disp.display()


#print 'Press Ctl-C to exit'

#functions
def getSnmpData (oid):
	
	try:
		data = subprocess.check_output("snmpget -v 1 -c public 192.168.0.1 " + oid, shell = True)
	except subprocess.CalledProcessError as e:
		data = e
	else:
		data = "unhandled error"
	return data;

def getSnmpInt (oid):

	try:
		data = subprocess.check_output("snmpget -v 1 -c public 192.168.0.1 " + oid, shell = True)
		data = data.split()
		data = data.pop()
	except:
		data = "0"
	return int(data)

def drawBar (x, barHeight):
	# parameters are x, y, end x, end y 
	draw.rectangle ((x, height - barHeight, x + 10, height -1), outline=255, fill=255)

def textRate (rate):
	rate = rate * 8 / 1000
	if rate < 1000:
		result = str(round(rate,1)) + ' kbps'
	else:
		result = str(round(rate/1000,1)) + ' mbps'
	return result

#defines
oidInWan = '1.3.6.1.2.1.2.2.1.10.1'
oidOutWan = '1.3.6.1.2.1.2.2.1.16.1'

lastInBytes = getSnmpInt (oidInWan);
lastOutBytes = getSnmpInt (oidOutWan);
lastTime = time.time()

maxRateIn = 565000
maxRateOut = 120000

#timed array vars
timerTime = time.time()
highestSpeedIn = 0
highestSpeedOut = 0
speedArrayIn = []
speedArrayOut = []
inMax = 0
outMax = 0

while (1):
	time.sleep(0.5)
	draw.rectangle((0, 0, width, height), outline=0, fill=0)
	
	now = time.time()
	elapsed = now - lastTime
	lastTime = now
	
	#calculate rates in and out
	inBytes = getSnmpInt (oidInWan)
	currInBytes = (inBytes - lastInBytes) / elapsed
	lastInBytes = inBytes

	outBytes = getSnmpInt (oidOutWan)
	currOutBytes = (outBytes - lastOutBytes) / elapsed
	lastOutBytes = outBytes

	#max rate last 24 hours calculations
	if currInBytes > highestSpeedIn:
		highestSpeedIn = currInBytes
	if currOutBytes > highestSpeedOut:
		highestSpeedOut = currOutBytes

	if now > timerTime + 3600:
		print '-----------------------------------------------------------------  time expired'
		timerTime = now

		speedArrayIn.append (highestSpeedIn)
		if len (speedArrayIn) > 23:
			del speedArrayIn[0]
		inMax = max(speedArrayIn)

		speedArrayOut.append (highestSpeedOut)
                if len (speedArrayOut) > 23:
                        del speedArrayOut[0]
		outMax = max(speedArrayOut)

		highestSpeedIn = 0
		highestSpeedOut = 0

		#test output
		for inSpd in speedArrayIn:
			print '--- ' + str(inSpd)
		print 'inMax ' + str(inMax)

	#adjust these in each loop in case we find a faster speed
	inMax = max(inMax, highestSpeedIn)
	outMax = max(outMax, highestSpeedOut)

	#print str(now) + '    ' + str(timerTime)
	print 'In: ' + textRate(currInBytes) + '\tOut: ' + textRate(currOutBytes) + '\tElapsed ' + str(round(elapsed,2)) + '\t\tInMax ' + textRate(inMax) + '\tOutMax ' + textRate(outMax)
	#print 'Hi In ' + str(highestSpeedIn) + '   Hi Out ' + str(highestSpeedOut)

	#draw graph
	inHeight = 0.0
	outHeight = 0.0
	if currInBytes > 0:	
		inHeight = float(currInBytes * height / inMax)  #was maxRateIn
	if currOutBytes > 0:
		outHeight = float(currOutBytes * height / outMax)  #was maxRateOut
	drawBar (0, inHeight)
	drawBar (117, outHeight)

	#write rates
	draw.text((20,44), textRate(currInBytes), font=font, fill=255)
        draw.text((20,54), textRate(currOutBytes), font=font, fill=255)
	#max rates
	draw.text((20,15), textRate(inMax), font=font, fill=255)
	draw.text((20,25), textRate(outMax), font=font, fill=255)

	#display
	disp.image(image)
	disp.display()