.. |br| raw:: html

      <br>

.. _ex_pp:

Point Perfect
=============

PointPerfect is an advanced GNSS augmentation data service designed from the ground up to be accurate, reliable, and immediately available. |br|
The service answers the fast-growing demand for high precision GNSS solutions: UAV, service robots, machinery automation, AD and ADAS, lane-accurate navigation, and telematics.

This example application connects to the PointPerfect service and runs a callback function everytime it receives a message. |br|
The callback function prints the "callback" word, message topic, message length and 10 first digits of the message payload.

.. note:: Make sure to adapt the network connection to yours (fixed IP or DHCP) by setting the Parameters class variables. |br| You need to download from u-blox Thingstream portal the credentials in JSON format and save them on the SBC memory without changing the name. |br| Please enter your PointPerfect credentials id on the pp_id parameter and set the topic on the topic variable.

::

	import time
	import network
	import uasyncio as asyncio
	import sbc
	import asmqtt
	import ujson

	class EGM:
		def __init__(self):
			self.par = self.Parameters()
		
		class Parameters:
			def __init__(self):
				self.uart_baud_rate = '115200'
				self.lan_dhcp = True
				self.lan_ip = '10.0.0.1'
				self.lan_sn = '255.255.255.0'
				self.lan_gw = '10.0.0.2'
				self.lan_dns = '8.8.8.8'
				self.pp_active = True
				self.pp_srv = 'pp.services.u-blox.com'
				self.pp_id = '02e7321d-f6fe-41a2-b493-92996c0a4e20'
				self.pp_topic = '/pp/ip/eu'
				
	def connectNetwork():
		try:
			lan.active(True)
			if(not egm.par.lan_dhcp):
				lan.ifconfig((egm.par.lan_ip, egm.par.lan_sn, egm.par.lan_gw, egm.par.lan_dns))
			while(lan.status() != 3):
				print('Connecting to LAN')
				time.sleep(1)
			print('LAN connected, configuration (ip, subnet, gateway, dns): ', lan.ifconfig())
			return(1)
		except:
			print("Check Ethernet cable is properly plugged")
			return(0)

	lan = network.LAN()
	egm = EGM()

	while(connectNetwork() == 0):
		time.sleep(1)

	def is_connected(lan):
		status = lan.phy_status()
		auto_negotiation_complete = (status>>5)&0x01
		link_up = (status>>2)&0x01
		return auto_negotiation_complete and link_up

	async def task_network(lan):    
		while(True):
			if(not is_connected(lan)):
				print("not is_connected(lan)")
				while(not is_connected(lan)):
					while(connectNetwork() == 0):
						await asyncio.sleep(1)
			else:
				print("is_connected(lan)")
				while(is_connected(lan)):
					await asyncio.sleep(1)
			await asyncio.sleep(1)
			
	async def task_point_perfect(client_id, server, port, key, cert, topic):
		ssl_params={"key" : key, "cert": cert, "server_side":False, "server_hostname":server, "do_handshake": True}
		mqtt = asmqtt.asMQTTClient(client_id, server, port=port, ssl=True, ssl_params=ssl_params)
		
		async def callback(topic, msg):
			print("callback", topic, len(msg), msg[0:10])
			print(msg)
			
		mqtt.set_callback(callback)
		
		await mqtt.connect()
		await mqtt.subscribe(b"/pp/ubx/0236/ip")
		await mqtt.subscribe(topic)
		
		while(True):
			await mqtt.wait_msg()
			await asyncio.sleep(0.1)
		
		await mqtt.disconnect()

	loop = asyncio.new_event_loop()
	loop.create_task(task_network(lan))

	try:
		fl = open('device-'+egm.par.pp_id+'-ucenter-config.json', "rb")
		pp_json_credentials = ujson.loads(fl.read())
		fl.close()
		pp_key = sbc.cert_tools.pem2der(pp_json_credentials['MQTT']['Connectivity']['ClientCredentials']['Key'])
		pp_cert = sbc.cert_tools.crt2der(pp_json_credentials['MQTT']['Connectivity']['ClientCredentials']['Cert'])
		
		loop.create_task(task_point_perfect(egm.par.pp_id, egm.par.pp_srv, 8883, pp_key, pp_cert, egm.par.pp_topic))
		print("Point Perfect initialized")
	except Exception as e:
		print('Problem starting Point Perfect, exception: ', e)
		try: print('Point Perfect server response: ' + str(response.content))
		except: pass

	loop.run_forever()