#!/usr/bin/env python # coding: Latin-1 # Creates a web-page interface for DiddyBorg # Import library functions we need import PicoBorgRev import time import sys import threading import SocketServer import picamera import picamera.array import cv2 import datetime import os # Settings for the web-page webPort = 80 # Port number for the web-page, 80 is what web-pages normally use imageWidth = 240 # Width of the captured image in pixels imageHeight = 180 # Height of the captured image in pixels frameRate = 10 # Number of images to capture per second displayRate = 10 # Number of images to request per second photoDirectory = '/home/pi' # Directory to save photos to jpegQuality =50 # JPEG quality level,smaller is faster,higher looks better (0-100) # Global values global PBR global lastFrame global lockFrame global camera global processor global running global watchdog running = True # Setup the PicoBorg Reverse PBR = PicoBorgRev.PicoBorgRev() #PBR.i2cAddress = 0x44 # Uncomment and change the value if you have changed the board address PBR.Init() if not PBR.foundChip: boards = PicoBorgRev.ScanForPicoBorgReverse() if len(boards) == 0: print ('No PicoBorg Reverse found, check you are attached :)') else: print ('No PicoBorg Reverse at address %02X, but we did find boards:') % (PBR.i2cAddress) for board in boards: print (' %02X (%d)') % (board, board) print ('If you need to change the I²C address change the setup line so it is correct, e.g.') print ('PBR.i2cAddress = 0x%02X') % (boards[0]) sys.exit() #PBR.SetEpoIgnore(True) # Uncomment to disable EPO latch, needed if you do not have a switch / jumper PBR.SetCommsFailsafe(False) # Disable the communications failsafe PBR.ResetEpo() # Power settings voltageIn = 1.2 * 10 # Total battery voltage to the PicoBorg Reverse voltageOut = 9.0 # Maximum motor voltage # Setup the power limits if voltageOut > voltageIn: maxPower = 1.0 else: maxPower = voltageOut / float(voltageIn) #wifi strength def WiFiSignalStrength(): # Get the WiFi signal strength using iwconfig wifiQuery = os.popen('iwconfig wlan0|grep Link|cut -d"=" -f2|cut -d" " -f1') wifiResult = wifiQuery.readlines() wifiQuery.close() # See if we are connected if len(wifiResult) == 0: # Not connected wifiStrength = 'Not connected' else: # Connected, the value we get here will be a division, e.g. 5/20 wifiResult = wifiResult[0] # Get the text wifiResult = wifiResult[:-1] # Remove the '\n' symbol from the end wifiValues = wifiResult.split('/') if len(wifiValues) == 2: # Get the percentage from the values wifiPercent = (float(wifiValues[0]) / float(wifiValues[1])) * 100.0 wifiStrength = '%.0f %%' % (wifiPercent) else: # Unexpected, show the returned text instead wifiStrength = wifiResult # Return the value return wifiStrength # Timeout thread class Watchdog(threading.Thread): def __init__(self): super(Watchdog, self).__init__() self.event = threading.Event() self.terminated = False self.start() self.timestamp = time.time() def run(self): timedOut = True # This method runs in a separate thread while not self.terminated: # Wait for a network event to be flagged for up to one second if timedOut: if self.event.wait(1): # Connection print ('Reconnected...') timedOut = False self.event.clear() else: if self.event.wait(1): self.event.clear() else: # Timed out print ('Timed out...') timedOut = True PBR.MotorsOff() # Image stream processing thread class StreamProcessor(threading.Thread): def __init__(self): super(StreamProcessor, self).__init__() self.stream = picamera.array.PiRGBArray(camera) self.event = threading.Event() self.terminated = False self.start() self.begin = 0 def run(self): global lastFrame global lockFrame # This method runs in a separate thread while not self.terminated: # Wait for an image to be written to the stream if self.event.wait(1): try: # Read the image and save globally self.stream.seek(0) flippedArray = cv2.flip(self.stream.array, -1) # Flips X and Y retval, thisFrame = cv2.imencode('.jpg', flippedArray) del flippedArray lockFrame.acquire() lastFrame = thisFrame lockFrame.release() finally: # Reset the stream and event self.stream.seek(0) self.stream.truncate() self.event.clear() # Image capture thread class ImageCapture(threading.Thread): def __init__(self): super(ImageCapture, self).__init__() self.start() def run(self): global camera global processor print ('Start the stream using the video port') camera.capture_sequence(self.TriggerStream(), format='bgr', use_video_port=True) print ('Terminating camera processing...') processor.terminated = True processor.join() print ('Processing terminated.') # Stream delegation loop def TriggerStream(self): global running while running: if processor.event.is_set(): time.sleep(0.01) else: yield processor.stream processor.event.set() # Class used to implement the web server class WebServer(SocketServer.BaseRequestHandler): def handle(self): global PBR global lastFrame global watchdog # Get the HTTP request data reqData = self.request.recv(1024).strip() reqData = reqData.split('\n') # Get the URL requested getPath = '' for line in reqData: if line.startswith('GET'): parts = line.split(' ') getPath = parts[1] break watchdog.event.set() if getPath.startswith('/cam.jpg'): # Camera snapshot lockFrame.acquire() sendFrame = lastFrame lockFrame.release() if sendFrame is not None: self.send(sendFrame.tostring()) elif getPath.startswith('/wifi-once'): # Display the WiFi signal strength httpText = '
' httpText += WiFiSignalStrength() httpText += '
' self.send(httpText) elif getPath == ('/wifi'): # Repeated reading of the WiFi strength, set a delayed refresh # We use AJAX to avoid screen refreshes caused by refreshing a frame displayDelay = int(1000 / displayRate) httpText = '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' % (displayDelay) httpText += '
Waiting for first distance reading...
\n' httpText += '\n' httpText += '\n' self.send(httpText) elif getPath.startswith('/shutdown'): # Shut the Raspberry Pi down httpText = '
' httpText += 'Shutting down...' httpText += '
' self.send(httpText) os.system('sudo shutdown -h now') elif getPath.startswith('/off'): # Turn the drives off httpText = '
' httpText += 'Speeds: 0 %, 0 %' httpText += '
' self.send(httpText) PBR.MotorsOff() elif getPath.startswith('/set/'): # Motor power setting: /set/driveLeft/driveRight parts = getPath.split('/') # Get the power levels if len(parts) >= 4: try: driveLeft = float(parts[2]) driveRight = float(parts[3]) except: # Bad values driveRight = 0.0 driveLeft = 0.0 else: # Bad request driveRight = 0.0 driveLeft = 0.0 # Ensure settings are within limits if driveRight < -1: driveRight = -1 elif driveRight > 1: driveRight = 1 if driveLeft < -1: driveLeft = -1 elif driveLeft > 1: driveLeft = 1 # Report the current settings percentLeft = driveLeft * 100.0; percentRight = driveRight * 100.0; httpText = '
' httpText += 'Speeds: %.0f %%, %.0f %%' % (percentLeft, percentRight) httpText += '
' self.send(httpText) # Set the outputs driveLeft *= maxPower driveRight *= maxPower PBR.SetMotor1(driveRight) PBR.SetMotor2(-driveLeft) elif getPath.startswith('/photo'): # Save camera photo lockFrame.acquire() captureFrame = lastFrame lockFrame.release() httpText = '
' if captureFrame is not None: photoName = '%s/Photo %s.jpg' % (photoDirectory, datetime.datetime.utcnow()) try: photoFile = open(photoName, 'wb') photoFile.write(captureFrame) photoFile.close() httpText += 'Photo saved to %s' % (photoName) except: httpText += 'Failed to take photo!' else: httpText += 'Failed to take photo!' httpText += '
' self.send(httpText) elif getPath == '/': # Main page, click buttons to move and to stop httpText = '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '
\n' httpText += '\n' httpText += '

\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '

\n' httpText += '\n' httpText += '

\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '

\n' httpText += '\n' httpText += '\n' httpText += '
\n' httpText += '\n' httpText += '\n' self.send(httpText) elif getPath =='/stream': # Streaming frame, set a delayed refresh displayDelay = int(1000 / displayRate) httpText = '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '\n' httpText += '
\n' httpText += '\n' % (displayDelay) httpText += '\n' httpText += '\n' httpText += '\n' self.send(httpText) else: # Unexpected page self.send('Path : "%s"' % (getPath)) def send(self, content): self.request.sendall('HTTP/1.0 200 OK\n\n%s' % (content)) # Create the image buffer frame lastFrame = None lockFrame = threading.Lock() # Startup sequence print ('Setup camera') camera = picamera.PiCamera() camera.resolution = (imageWidth, imageHeight) camera.framerate = frameRate print ('Setup the stream processing thread') processor = StreamProcessor() print ('Wait ...') time.sleep(2) captureThread = ImageCapture() print ('Setup the watchdog') watchdog = Watchdog() # Run the web server until we are told to close httpServer = SocketServer.TCPServer(("0.0.0.0", webPort), WebServer) try: print ('Press CTRL+C to terminate the web-server') while running: httpServer.handle_request() except KeyboardInterrupt: # CTRL+C exit print ('\nUser shutdown') finally: # Turn the motors off under all scenarios PBR.MotorsOff() print ('Motors off') # Tell each thread to stop, and wait for them to end running = False captureThread.join() processor.terminated = True watchdog.terminated = True processor.join() watchdog.join() del camera PBR.SetLed(True) print ('Web-server terminated.')