Raspberry Pi Weather Station

On 19 June, the USB temperature sensor I ordered from Amazon arrived. This sensor is now hooked up to my Raspberry Pi, which is taking the temperature every 10 minutes, drawing graphs, then uploading them here. Here is a brief outline of how I set this up (I'm writing this nearly two weeks after I did it so if you can't follow any of the steps let me know and I'll try to work out what I've missed out):

Reading the Temperature

I found this code and adapted it to write the date, time and temperature to a text file. I then set cron to run this every 10 minutes. It writes the data to a text file (/var/www/temperature2) in this format:

2013 06 20 03 50,16.445019 2013 06 20 04 00,16.187843 2013 06 20 04 10,16.187843 2013 06 20 04 20,16.187843

Plotting the Graphs

I found a guide somewhere on the internet about how to draw graphs with Python using Pylab/Matplotlib. If you have any idea where this could be, comment below and I'll put a link here.

In the end my code looked like this:

import time import matplotlib as mpl mpl.use('Agg') import matplotlib.pylab as plt import matplotlib.dates as mdates ts = time.time() import datetime now=datetime.datetime.fromtimestamp(ts) st = mdates.date2num(datetime.datetime(int(float(now.strftime('%Y'))),int(float(now.strftime('%m'))),int(float(now.strftime('%d'))),0,0,0)) weekst = st-int(float(datetime.datetime.fromtimestamp(ts).strftime('%w'))) f=file('/var/www/temperature2','r') t=[] s=[] tt=[] ss=[] u=[] v=[] g=[] h=[] i=[] weekt=[] weektt=[] weeks=[] weekss=[] mini=1000 maxi=0 cur=-1 datC=0 for line in f: fL=line.split(",") fL[0]=fL[0].split(" ") if cur==-1: cur=mdates.date2num(datetime.datetime(int(float(fL[0][0])),int(float(fL[0][1])),int(float(fL[0][2])),0,0,0)) datC=mdates.date2num(datetime.datetime(int(float(fL[0][0])),int(float(fL[0][1])),int(float(fL[0][2])),int(float(fL[0][3])),int(float(fL[0][4])),0)) u.append(datC) v.append(fL[1]) if datC>=st and datC<=st+1: t.append(datC) s.append(fL[1]) if datC>=st-1 and datC<=st: tt.append(datC+1) ss.append(fL[1]) if datC>=weekst and datC<=weekst+7: weekt.append(datC) weeks.append(fL[1]) if datC>=weekst-7 and datC<=weekst: weektt.append(datC+7) weekss.append(fL[1]) if datC>cur+1: g.append(cur) h.append(mini) i.append(maxi) mini=1000 maxi=0 cur=mdates.date2num(datetime.datetime(int(float(fL[0][0])),int(float(fL[0][1])),int(float(fL[0][2])),0,0,0)) mini=min(float(fL[1]),mini) maxi=max(float(fL[1]),maxi) g.append(cur) h.append(mini) i.append(maxi) plt.plot_date(x=t,y=s,fmt="r-") plt.plot_date(x=tt,y=ss,fmt="g-") plt.xlabel("Time") plt.ylabel("Temperature ($^\circ$C)") plt.title("Daily") plt.legend(['today','yesterday'], loc='upper left',prop={'size':8}) plt.grid(True) plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%H:%M')) plt.gcf().subplots_adjust(bottom=0.15,right=0.99) labels = plt.gca().get_xticklabels() plt.setp(labels,rotation=90,fontsize=10) plt.xlim(st,st+1) plt.savefig('/var/www/tempr/tg1p.png') plt.clf() plt.plot_date(x=weekt,y=weeks,fmt="r-") plt.plot_date(x=weektt,y=weekss,fmt="g-") plt.xlabel("Day") plt.ylabel("Temperature ($^\circ$C)") plt.title("Weekly") plt.legend(['this week','last week'], loc='upper left',prop={'size':8}) plt.grid(True) plt.gca().xaxis.set_major_formatter(mdates.DateFormatter(' %A')) plt.gcf().subplots_adjust(bottom=0.15,right=0.99) labels = plt.gca().get_xticklabels() plt.setp(labels,rotation=0,fontsize=10) plt.xlim(weekst,weekst+7) plt.savefig('/var/www/tempr/tg2p.png') plt.clf() plt.plot_date(x=u,y=v,fmt="r-") plt.xlabel("Date & Time") plt.ylabel("Temperature ($^\circ$C)") plt.title("Forever") plt.grid(True) plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%d/%m/%y %H:%M')) plt.gcf().subplots_adjust(bottom=0.25,right=0.99) labels = plt.gca().get_xticklabels() plt.setp(labels,rotation=90,fontsize=8) plt.savefig('/var/www/tempr/tg4p.png') plt.clf() plt.plot_date(x=g,y=h,fmt="b-") plt.plot_date(x=g,y=i,fmt="r-") plt.xlabel("Date") plt.ylabel("Temperature ($^\circ$C)") plt.title("Forever") plt.legend(['minimum','maximum'], loc='upper left',prop={'size':8}) plt.grid(True) plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%d %b')) plt.gcf().subplots_adjust(bottom=0.15,right=0.99) labels = plt.gca().get_xticklabels() plt.setp(labels,rotation=90,fontsize=8) plt.savefig('/var/www/tempr/tg3p.png')

If there's anything in there you don't understand, comment below and I'll try to fill in the gaps.

Uploading the Graphs to catsindrag.co.uk

Finally, I wrote a php script to upload the graphs to catsindrag.co.uk/weather:

$filename=Array("tg1p.png","tg2p.png","tg3p.png","tg4p.png"); for($i=0;$i<count($filename);$i++){ $localfile="/var/www/tempr/".$filename[$i]; $fp = fopen($localfile, "r"); $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "ftp://USERNAME:PASSWORD@catsindrag.co.uk/sites/www.catsindrag.co.uk/public_html/weather/".$filename[$i]); curl_setopt($ch, CURLOPT_UPLOAD, 1); curl_setopt($ch, CURLOPT_INFILE, $fp); curl_setopt($ch, CURLOPT_INFILESIZE, filesize($localfile)); curl_exec($ch); curl_close($ch); }

I hope this was vaguely interesting/useful. I'll try to add more details and updates over time. If you are building something similar, please let me know in the comments; I'd love to see what everyone else is up to.