1.44 TFT LCD ST7735S is not working as expected

[mnrozhkov]

Hi! I have this 1.44" SPI 128x128 TFT LCD Display (RED PCB V1.1) with following specs: conf/st7735.conf:

--display=st7735
--interface=spi
--spi-bus-speed=16000000
--gpio-reset=24
--gpio-data-command=23
--gpio-backlight=18
--width=128
--height=128

1) When running an example sudo python examples/3d_box.py -f conf/st7735.conf , there is nothing on the screen! Even the backlight is not enabled.

2) After I connect gpio-backlight pin directly to 3.3V source - it works fine

Notes:

1. It seems that code can't reach/control some of the required GPIO or numbering is wrong. (I've used BCM numbering)

2. When I follow 'Python usage' instructions nothing happens when I try 'draw.rectangle' or 'draw.text'

3. When I try to get the 'device' object details in runtime (run with -f conf/st7735.conf), I see the unexpected arguments for screen size (my LCD has width=128, height=128):

   luma.lcd.device.st7735 at 0x765da3b0 (
   bounding_box = (0, 0, 159, 127),
   framebuffer = luma.core.framebuffer.diff_to_previous at 0x765da7f0 (
     bounding_box = (0, 0, 160, 128),
     image = PIL.Image.Image at 0x76359b90 (
         category = 0,
         format = None,
         format_description = None,
         height = 128,
         im = ImagingCore at 0x76d6afa0 (
             bands = 3,
             id = 22136808,
             mode = 'RGB',
             ptr = PyCapsule at 0x7655f020 (),
             size = (160, 128),
             unsafe_ptrs = ((...), (...), (...), (...), (...), ..., (...), (...), (...), (...), (...))
           ),
         ...,
         palette = None,
         pyaccess = None,
         readonly = 0,
         size = (160, 128),
         width = 160
       )
   ),
   height = 128,
   mode = 'RGB',
   rotate = 0,
   size = (160, 128),
   width = 160
   )

Do you have any suggestions?

[rm-hull]

See the comment in #39 - i took a decision (wrongly) to hardcode the resolution to 160x128 thinking that was the only resolution. I will push a change so it supports 128x128 but it won't be for another few days.

As to the issue with the backlight, i don't know. I have bought one of these devices but haven't had the chance to plug it in. I will update the ticket with my findings

[rm-hull]

@mnrozhkov there is a new version that supports 128x128 variants of this device. If you upgrade with:

$ sudo -H pip install --upgrade luma.core luma.lcd

The backlight was originally written for the PCD8544 which is enabled as active-low, whereas the ST7735 enables the backlight as active-high. It is now configurable, so supports either setting.

Lastly, if you then pull from master for the luma.examples repo, and you should find a conf/st7735_128x128.conf file with the correct settings (well, this works on the 128x128 device I have).

Let me know how you get on,

[thijstriemstra]

@mnrozhkov any news?

[mnrozhkov]

@rm-hull thanks a lot! It works well. I've updated library and changed conf.

I use LCD to build eyes for my robot. I'll share with you how it will word as soon as I finish this. Your library is priceless help for our project!

Best wishes!