[Python] Python pygame fails to output to /dev/fb1 on a Raspberry Pi + TFT screen

TL;DR


I am fiddling with a Raspberry Pi 2 and a 2.8" TFT touch screen attached to the Pi's GPIO. The Pi is also connected to a HDMI monitor.
My issue is that my Python3 pygame script is not able to use the TFT screen, but always displays on my HDMI screen instead.

Some background


I've installed the latest vanilla Raspbian ready-to-use distro and followed the TFT screen installation steps, everything works well: the TFT can display the console and X without issue. The touchscreen is calibrated and moves the cursor correctly. I can also see a new framebuffer device as /dev/fb1.

I've tried the following to test this new device:

sudo fbi -T 2 -d /dev/fb1 -noverbose -a my_picture.jpg


=> This successfully displays the pic on the TFT screen

while true; do sudo cat /dev/urandom > /dev/fb1; sleep .01; done


=> This successfully displays statics on the TFT screen

However, when I run this Python3/pygame script, the result appears in the HDMI screen consistently and not on the TFT screen:

#!/usr/bin/python3

import os, pygame, time

def setSDLVariables():
print("Setting SDL variables...")
os.environ["SDL_FBDEV"] = "/dev/fb1"
os.environ["SDL_VIDEODRIVER"] = driver
print("...done")

def printSDLVariables():
print("Checking current env variables...")
print("SDL_VIDEODRIVER = {0}".format(os.getenv("SDL_VIDEODRIVER")))
print("SDL_FBDEV = {0}".format(os.getenv("SDL_FBDEV")))

def runHW5():
print("Running HW5...")
try:
pygame.init()
except pygame.error:
print("Driver '{0}' failed!".format(driver))
size = (pygame.display.Info().current_w, pygame.display.Info().current_h)
print("Detected screen size: {0}".format(size))
lcd = pygame.display.set_mode(size)
lcd.fill((10,50,100))
pygame.display.update()
time.sleep(sleepTime)
print("...done")

driver = 'fbcon'
sleepTime= 0.1

printSDLVariables()
setSDLVariables()
printSDLVariables()
runHW5()


The script above runs as follow:

pi@raspberrypi:~/Documents/Python_HW_GUI $ ./hw5-ThorPy-fb1.py
Checking current env variables...
SDL_VIDEODRIVER = None
SDL_FBDEV = None
Setting SDL variables...
...done
Checking current env variables...
SDL_VIDEODRIVER = fbcon
SDL_FBDEV = /dev/fb1
Running HW5...
Detected screen size: (1920, 1080)
...done


I have tried different drivers (fbcon, directfb, svgalib...) without success.

Any help or idea would be greatly appreciated, I've been through a lot of doc, manuals and samples and just ran out of leads :/ Furthermore, it appears that a lot of people have succeeded in getting Python3/pygame to output to their TFT screen via /dev/fb1.

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