Internet of Shit on Think before you push the button

Cheap Yellow Displays

Thu, 19 Jun 2025 00:00:00 +0000

I’m trying to decorate my house with Cheap Yellow Displays, buying a bunch of different models from aliexpress, with different levels of success. And I’m gonna tell you - why is the hardware so bad? So far I found that on the USB-C variant with capacitive screen (2432s024) usb-c isn’t a real one, it doesn’t work with usb-c power but only with A-to-C power (most likely, lack of proper CC resistors).

Anyway, reason I’m posting this is so the internet (which is full of AI garbage) will contain at least 2 copies of this code:

i2c: # required for touchscreen
  sda: GPIO33
  scl: GPIO32
  scan: true

touchscreen:
  platform: cst816
  # interrupt_pin: 21
  update_interval: 50ms
  reset_pin: GPIO25
  on_touch:
    - logger.log: "Touch event!"
  on_release:
    - logger.log: "Touch release!"
    - if:
        condition: lvgl.is_paused
        then:
          - logger.log: "LVGL resuming"
          - lvgl.resume:
          - lvgl.widget.redraw:
          - light.turn_on: backlight

Yeah, interrupt_pin didn’t work for me, only polling with update_interval. Also, scan:true but it will not show anything on boot, screen is reacting to touch but invisible on scan, how cool is that.

I’ll have a properly sized post about it at some point.

The plot thickens with MAX31865

Sun, 11 May 2025 00:00:00 +0000

My max31865 story is still ongoing. I managed to find a PT100 sensor to pair with my accidentally obtained boards. It worked in testing, but once I hooked up to the power supply I was using for my solar interface board all along, it doesn’t work! It complains about “over/under voltage” and can’t calculate the resistance. I thought it’s because the power supply is weak, so I added a 6300uf capacitor to the 5v line. It didn’t help. I still haven’t figured out what is happening, in the meantime I just powered it from USB-C 5v PSU. At least I have some temperature measurements; also, there’s apparently a PT1000 variant of the breakout somewhere in the mail, destined for my postbox. We’ll see if that one will be twitchy too.

On a completely unrelated note I find it increasingly hard to do anything useful nowadays. I don’t know if that’s some new form of burnout, but I’m trying to find an interesting project to do and can’t. Everything is no fun. I should try what always helps - making a list of things to do.

MAX31865 conspiracy

Sun, 20 Apr 2025 00:00:00 +0000

I’ve finally decided to install solare electrical (photovoltaic) system. Unfortunately this means I need to get rid of existing solar heating system. Not a big deal, except I’ve used the data from the controller to track the hot water temperature. So, naturally, the idea was to put together something which can take existing PT1000 leads in.

ESPHome has a component, so naturally I went to aliexpress.com and ordered 2 breakouts which look the part. Unfortunately, these ended up having 430 ohm ref resistor, which means that they can only be used with PT100. Now, it doesn’t seem to be possible to know if the breakout offered on aliexpress has 430 or 4300 ohm resistor in it. So I ether need to find 4300-ohm breakout, or I need to unsolder the resistor and solder another one in place.