Using my 1.8 TFT as a Raspberry Pi status display

I have been experimenting with my Raspberry Pi TFT display these few days with the intention to use it as a misc status display, heavily influenced by Mark‘s work. I collect most of my house’s telemetrics to an emoncms installation running on the server where I host this blog, so I will pull some of the data I need to visualize from there. I would be showing information such as

• Room temperatures (transmitted by multiple Funky+DS18B20)
• Outside air temperature and humidity (measured with Funky+DHT22)
• Heat pump telemetrics (power consumption, multiple temperature measurements as described here)
• House power consumption as described here 
• Solar hot water tank telemetrics (gathered as explained here and here)
• Misc weather data from Weather Underground, data collected using the method I explained here

The python script is pretty self-explanatory, it uses pygame to generate the screens on the framebuffer device. This is work in progress, I will expand the script with IR remote control with Funky, so I can chose which specific page to show or other functions that I haven’t decided on yet.

I think that pulling and displaying satellite weather data from Weather  Undergound for my area is pretty cool too:

Another cool part is displaying overlayed emoncms data for outside/ room temperatures and heat pump power usage as per my post here; I use a slightly simplified chart sized down to 160×128 pixels and display that one too:

 No room for legends but I already know the colors by heart 🙂

Yet another cool thing is to overlay weather icons on the outside temperature page, using Weather Undergound API to get actual icon:

The code

#!/usr/bin/python

import pygame
import sys
import time
from time import strftime
import os
import httplib
import urllib
import json

time_stamp_prev=0

#Set the framebuffer device to be the TFT
os.environ["SDL_FBDEV"] = "/dev/fb1"

#Get emoncms feed latest data
def getFeedVal(feedId):
	conn = httplib.HTTPConnection("*******SITE**********")
	conn.request("GET", "/emoncms3/feed/value.json?apikey=*******API**********&id=" + feedId)
	response = conn.getresponse()
	#print response.status, response.reason
	data = response.read()
	conn.close()
 	return data

def getWUnder():
	global time_stamp_prev
	# Only fetch latest data once every while, or we will violate WU's rules
	if (time.time() - time_stamp_prev) > 15*60:
		time_stamp_prev = time.time()
		f = urllib.urlopen('http://api.wunderground.com/api/*******W.U. key**********/geolookup/conditions/q/sofia.json')
		json_string = f.read()
		parsed_json = json.loads(json_string)
		#temp_c = parsed_json['current_observation']['temp_c']
		#print "Current temperature in %s is: %s" % (location, temp_c)
		#Also see http://www.wunderground.com/weather/api/d/docs?d=resources/icon-sets
		iconurl = parsed_json['current_observation']['icon_url']
		urllib.urlretrieve (iconurl, "graph.gif")
		f.close()

		#http://www.wunderground.com/weather/api/d/docs?d=layers/satellite
		urllib.urlretrieve ("http://api.wunderground.com/api/*******W.U. key**********/satellite/q/KS/Sofia.gif?width=160&height=128&basemap=1","satellite.gif")

def displayTime():
#    """Used to display date and time on the TFT"""
    screen.fill((0,0,0))
    font = pygame.font.Font(None, 50)
    now=time.localtime()

    for setting in [("%H:%M:%S",60),("%d  %b",10)] :
         timeformat,dim=setting
         currentTimeLine = strftime(timeformat, now)
         text = font.render(currentTimeLine, 0, (0,250,150))
         Surf = pygame.transform.rotate(text, -90)
         screen.blit(Surf,(dim,20))

def displayText(text, size, line, color, clearScreen):

    """Used to display text to the screen. displayText is only configured to display 
    two lines on the TFT. Only clear screen when writing the first line"""
    if clearScreen:
        screen.fill((0, 0, 0))

    font = pygame.font.Font(None, size)
    text = font.render(text, 0, color)
    textRotated = pygame.transform.rotate(text, -90)
    textpos = textRotated.get_rect()
    textpos.centery = 80   
    if line == 1:
         textpos.centerx = 90
         screen.blit(textRotated,textpos)
    elif line == 2:
        textpos.centerx = 40
        screen.blit(textRotated,textpos)

def main():
	global screen
	pygame.init()

	size = width, height = 128, 160
	black = 0, 0, 0

	pygame.mouse.set_visible(0)
	screen = pygame.display.set_mode(size)

#HP boiler=11
#Solar boiler=16
#Living room t=76
#Kids room t=18
#Outside temp=71
#Outside humidity=70

	while True:

		getWUnder()

		displayTime()
		pygame.display.flip()
		time.sleep(10)

		displayText('Outside Temp', 30, 1, (200,200,1), True )
		displayText(getFeedVal("71") + "C", 50, 2, (150,150,255), False )

		graph = pygame.image.load("graph.gif")
		graph = pygame.transform.rotate(graph, 270)
		graphrect = graph.get_rect()
		screen.blit(graph, graphrect)

		pygame.display.flip()
		time.sleep(10)

	 	displayText('Out. Humidity', 30, 1, (200,200,1), True )
		displayText(getFeedVal("70") + "%", 50, 2, (150,150,255), False )
		pygame.display.flip()
		time.sleep(10)

	 	displayText('Solar boiler', 30, 1, (200,200,1), True )
		displayText(getFeedVal("16") + "C", 50, 2, (150,150,255), False )
		pygame.display.flip()
		time.sleep(10)

	 	displayText('HP Boiler', 30, 1, (200,200,1), True )
		displayText(getFeedVal("11") + "C", 50, 2, (150,150,255), False )
		pygame.display.flip()
		time.sleep(10)

		urllib.urlretrieve ("http://******* path to my site**********.php", "graph.png")
		graph = pygame.image.load("graph.png")
		graph = pygame.transform.rotate(graph, 270)
		graphrect = graph.get_rect()
		screen.fill(black)
		screen.blit(graph, graphrect)
		pygame.display.flip()
		time.sleep(10)

		graph = pygame.image.load("satellite.gif")
		graph = pygame.transform.rotate(graph, 270)
		graphrect = graph.get_rect()
		screen.fill(black)
		screen.blit(graph, graphrect)
		pygame.display.flip()
		time.sleep(10)

if __name__ == '__main__':
    main()

To autostart the script on boot I did

sudo nano /etc/init.d/tft

and the tft script goes like this:

#! /bin/sh

# If you want a command to always run, put it here

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting TFT status display.."
    sudo python /home/pi/python/pg.py &
    ;;
  stop)
    ;;
  *)
    echo "Stopping TFT.."
    killall python
    exit 1
    ;;
esac

Finally, these commands will register your script to run at boot and shutdown:

sudo chmod +x  /etc/init.d/tft
sudo update-rc.d tft defaults