preenfm Forum

PreenFM => preenfm2 and preenfm3 => Topic started by: served on May 14, 2023, 01:41:42 PM

Title: Custom Pfm3 screen development.
Post by: served on May 14, 2023, 01:41:42 PM
Hello.

We have been dreaming of a custom made screen for PFM3.
There is always issues with the chineese versions. They come in different shapes. Some have completely wrong PCB layout for the SD card. Some have a different PCB diemensions. Some dont work at all due to bad quality or broken screen.
So me as a Preen builder have always struggled witht screens. You never know whats in the box.

Took some time, but finally I found time to make my own pcb for the screen.

Some notes on the process.

* MicroSD card instead of SD.
* no touchscreen pins
* 1.6mm pcb thickness.
* 3.3V for the screen and SD card. Chineese screens are using lower voltages for some reason.
* voltage regulator in bigger package for better heat dissipation. Pcb layout adjusted to support it.
* 3 Separate voltage rails and filtering groups for microSD card, screen logic and screen background light. This will take care of the wandering pulses in power rails.

The screens will be prebuilt in PCB fab except the glassbody, this has to be hand soldered.
We will test all the screens before shipping.

https://vandaal-electronics.com/wp-content/uploads/2020/11/20230509_091927-scaled.jpg (https://vandaal-electronics.com/wp-content/uploads/2020/11/20230509_091927-scaled.jpg)

https://vandaal-electronics.com/wp-content/uploads/2020/11/20230509_091920.jpg (https://vandaal-electronics.com/wp-content/uploads/2020/11/20230509_091920.jpg)
Title: Re: Custom Pfm3 screen development.
Post by: Groundloop on May 14, 2023, 03:49:04 PM
This is super interesting. Will these be suitable for DIY builds with the faceplate/ 3D printed case or are they tailored for the metal case you sell?
Title: Re: Custom Pfm3 screen development.
Post by: served on May 14, 2023, 08:06:57 PM
Physically they are the same as the chineese. There are no difference if you use metal case or 3d print.
Idea was to ship it with metal case to save on shipping. But I can send the screen separately no problem.