UKHAS Wiki

This is in python, you can find a detailed guide on installing python on the NGW100 here. The reed_solomon library can be found on the wiki here

#!/media/mmcblk0p1/install/bin/python
 
import reed_solomon
import serial
import math
import time
import os
TRUE=1
FALSE=0
mynumber=#ha you really thought I'd post it on here?
default_target_pressure=40
start_altitude=200                 #sampling starts here
limit=[10000,20000]                #our altitude ranges for the different samples
callsign="AOPP"
logname="flightlog.txt"
global Jxpoints
global Jypoints
global Iterations
global Roottwomgovercda
 
 
def gps_status():
	print 'Retrieving GPS status'
	gpspos_parts[0]=''	
	while not gpspos_parts[0]=='$GPGGA':
		gpspos=ser_gr.readline()
		gpspos_parts = gpspos.split(',')
	if ((gpspos_parts[6]=='2') or (gpspos_parts[6]=='3')): #2D or 3D fix
		print 'GPS fix' , gpspos_parts[6] , 'ie valid'
		gpsstatus=TRUE
	else:
		print 'GPS fix' , gpspos_parts[6] , 'ie not valid'
		status=FALSE
	return status
 
def gps_data():
	print 'Retrieving GPS data'
	gpspos_parts[0]=''	
	while not gpspos_parts[0]=='$GPGGA':
		gpspos=ser_gr.readline()
		gpspos_parts = gpspos.split(',')
	gpstime=3600*float(gpspos_parts[1][0:2])+60*float(gpspos_parts[1][2:4])+float(gpspos_parts[1][4:])
	latitude=float(gpspos_parts[2][0:2])+float(gpspos_parts[1][2:])/60.0 
	if gpspos_parts[3]=="S":
		latitude=-latitude
	longitude=float(gpspos_parts[4][0:3])+float(gpspos_parts[4][3:])/60.0
	if gpspos_parts[5]=="W":
		longitude=-longitude
	altitude=float(gpspos_parts[9])
	return gpstime,latitude,longitude,altitude
 
def db_stats():
	ser_daughter.write("V1\r\n")      #the high voltage values
	V1=ser_daughter.readline()
	ser_daughter.write("V2\r\n")
	V2=ser_daughter.readline()	
	ser_daughter.write("V3\r\n")
	V3=ser_daughter.readline()
	ser_daughter.write("I\r\n")        #the total ioniser current
	IC=ser_daughter.readline()
	ser_daughter.write("B\r\n")        #battery voltage
	VB=ser_daughter.readline()
	ser_daughter.write("D\r\n")        #pressure difference
	PD=ser_daughter.readline()
	ser_daughter.write("T\r\n")        #new - temperature sensor, to be fitted
	TS=ser_daugher.readline()
	return V1,V2,V3,IC,VB,PD,TS
 
def HV_enable(n);
	stringy='H'+str(n)+"\r\n"
	ser_daughter.write(stringy)
	print ser_daughter.readline()
 
def Set_pressure_target(P);
	ser_daughter.write('P'+str(P)+"\r\n")
 
def Updatepredict(Seconds,North,East,Altitude):
	global Predictedn	                                      #means they keep their values
	global Predictede	
	global Oldeast
	global Oldnorth
	global Oldseconds
	global Oldaltitude
	if Iterations==0:
		Predictedn=North
		Predictede=East
		Oldeast=East                                            #start
		Oldnorth=North
		Oldaltitude=Altitude
		Oldseconds=Seconds
	Deltae=East-Oldeast
	Deltan=North-Oldnorth
	Deltaa=Altitude-Oldaltitude
	Deltat=Seconds-Oldseconds
	Averagealt=(Oldaltitude+Altitude)/2
	Oldeast=East
	Oldnorth=North
	Oldaltitude=Altitude
	Oldseconds=Seconds
	if Deltaa>0:
		K=Roottwomgovercda*0.90909*math.exp(Averagealt/16000)  #we now have the velocity of decent
		print "Descent velocity=",K
		K=Deltaa/K                                            #time of decent for this layer
		print "descent time=",K
		K=K/Deltat                                            #weighting for this layer
		print "Layer weighting=",K
		K=K+1                                                 #need to account for ascent drift
		Predictedn+=K*Deltan
		Predictede+=K*Deltae
	print "predicted north=",Predictedn
	print "predicted east=",Predictede
	return Predictedn,Predictede
 
 
def are_we_inside(gpstime,Xpos,Ypos,altitude):
	count=False
	for g in range(len(Jxpoints)-1):
		if g==len(Jxpoints)-1:
			gplus=0
		else:
			gplus=g+1
		if ((Jypoints[g]>Ypos and Jypoints[gplus]<Ypos) or (Jypoints[g]<Ypos and Jypoints[gplus]>Ypos))and((Jxpoints[g]-Xpos)+(Ypos-Jypoints[g])*(Jxpoints[gplus]-Jxpoints[g])/(Jypoints[gplus]-Jypoints[g])>0):
			count=not count
	print 'we are inside=',count
	return count
 
def load_kml(filepath):
	xpoints=[]
	ypoints=[]
	found=False	
	for line in open(filepath,'r').readlines():
		if not line.find("<coordinates>")==-1:
			found=True
		if not line.find("</coordinates>")==-1:
			found=False		
		if found:
			line_split=line.split(',')
			if len(line_split)==3:			
				xpoints+=[float(line_split[0])]
				ypoints+=[float(line_split[1])]
	return xpoints,ypoints
 
def send_sms(s,target,smscen):
	target=str(target)
	smscen=str(smscen)
	if not (len(target)==12 and len(smscen)==12):
		print "phone numbers incorrect lenght"
		return -1
	if len(s)>160:
		print "text is too long"
		return -1
	E=0
	D=1
        stringy=""
	t=""
	Bitstring=[0]
	for G in s:
		Numb=ord(G)
   		for M in range(7):
			if (Numb >> M) & 1:
				Bitstring[E]+=D
			D*=2
    			if D==256:
				D=1
				E=E+1
				Bitstring.append(0)
	print "SMS"
	stringy="AT+CMGS="+str(14+(int(len(s)*7/8)+1))
	print stringy
	#ser_phone.write(stringy)
	#print ser_phone.readline()
	stringy="0791"
	for g in range(6):
		stringy+=(smscen[2*g+1])
		stringy+=(smscen[2*g])
	stringy+="11000C91"
	for g in range(6):
		stringy+=(target[2*g+1])
		stringy+=(target[2*g])
	stringy+="0000AA"             #PDU string to Mobile
	stringy+="%.2X" % len(s)
	for G in Bitstring:
		stringy+="%.2X" % G
	stringy+=chr(026)
	#ser_phone.write(stringy)
	#print ser_phone.readline()
	print stringy
	return 0
 
def get_smscen():
	ser_phone.write("AT+CSCA?")
	s=ser_phone.readline()
	s=s.split('"')
	return s[1:]
 
def cutdown():
	ser_gr.write("Cutdown...   ")
	shutdown()
	os.system("echo 0 > /config/gpio/cutterone/enabled")      #payload release
	time.sleep(6)
	os.system("echo 1 > /config/gpio/cutterone/enabled")      #and we are on the way down
	print "released"
 
def shutdown():
	HV_enable(0)             #all off
	Set_pressure_target(0)	 #pump off
	time.sleep(1)            #wait, to avoid smoke contamination
	os.system("echo 0 > /config/gpio/cuttertwo/enabled")      #cut plunger 
	time.sleep(3)
	os.system("echo 1 > /config/gpio/cuttertwo/enabled")	
	print "plunger cut"
	ser_gr.write("Shutdown\r\n")
 
finally:
	log.close()
 
 
print 'AOPP aerosol experiment running'
ser_gr=serial.Serial('/dev/ttyS2',4800, timeout=2, rtscts=1)    #we have a CTS line from the radio
ser_daughter=serial.Serial('/dev/ttyS1',19200, timeout=2)
ser_phone=serial.Serial('/dev/ttyS0',9600,timeout=4)
print 'serial is open to gps,radio, and daughterboard'
ser_gr.write("Hello world")
reed_solomon.setup_rs()
ser_gr.write(reed_solomon.encode_string("Hello, I am a reed solomon encoded string :P"))
while not gps_status:
	ser_gr.write("waiting for the gps to lock")
print 'ok, gps is ready, we are at:'
ser_gr.write("GPS locked")
print gps_data
print 'now probing daughterboard'
print db_stats()
print 'DANGER: turning on HV1'
HV_enable(1)
print 'HV1 on, probing board'
print db_stats()
print 'testing other HV channels'
for x in [2,3]:
	time.sleep(1)
	HV_enable(x)
	print 'HV channel' + str(x) + 'stats:' + db_stats()
HV_enable(0)
print 'ok, now testing the pump @ 20%'
Set_pressure_target(20)
for i in range(20):
	print db_stats()
	time.sleep(1)
Set_pressure_target(0)
for i in range(6):
	print db_stats()
	time.sleep(1)
print 'Testing done'
print 'opening KML cutdown file'
Jxpoints,Jypoints=load_kml('/media/mmcblk0p1/cutdown.kml')
print Jxpoints,Jypoints
print 'testing phone'
ser_phone.write("AT")
print ser_phone.readline()
smscen=get_smscen()
send_sms("hello world",mynumber,smscen)
ser_daughter.flushinput()
count=0
iterations=0
layercounter=0
cut_down=''
system_vector=gps_data()
maxaltitude=system_vector[3]
log=open("/media/mmcblk0p1/"+logname,"a+")
print 'ok launch the fucking balloon'
while 1:
	print 'in loop'
	iterations+=1
	system_vector=gps_data()
	daughter_board=db_stats()
	datastring=str(system_vector)+str(daughter_board)+cut_down
	log.write(datastring+"\r\n")
	ser_gr.write(reed_solomon.encode_string(callsign+datastring)))         #all our telemetery over the radio link
	if count=2:
		send_sms(datastring,mynumber,smscen)                  #every third time
		count=0
		os.system("sync")
	count+=1
	if system_vector[3]/100>layercounter:                                 #100m altitude layers
		layercounter+=1                                               #we move up a layer
		if !are_we_inside([0]+Updatepredict(system_vector)+[0]):      #update and check against the polygon
			print "geofence cutdown"
			log.write("geofence cutdown\r\n")		
			cutdown()
			cut_down='CG'
	if system_vector[0]-startuptime>max_flight_time:
		print "time cutdown"
		log.write("time cutdown\r\n")
		cutdown()
		cut_down='CT'
	if daughter_board[4]<battery_limit:
		print "voltage cutdown"
		log.write("voltage cutdown\r\n")		
		cutdown()
		cut_down='CB'
	if system_vector[3]-maxaltitude<-100:
		print "balloon popped"
		log.write("balloon popped\r\n")
		shutdown()
		cut_down='BP'
	if system_vector[3]>maxaltitude:
		maxaltitude=system_vector[3]
	if system_vector[3]>start_altitude:
		print 'turning on the pump (setting pressure target)'
		HV_enable(1)
		Set_pressure_target(default_target_pressure)
		log.write("HV1 on\r\n")
	if system_vector[3]>limit[1]:                                #set the right HV channel for the altitude                                
		if system_vector[3]<limit[2]:
			HV_enable(2)
			log.write("HV2 on\r\n")
		else
			HV_enable(3)
			log.write("HV3 on\r\n")
	time.sleep(10)                                              #10 seconds sleep