Changes in the project

A project log for nWatch

Selfmade watch that helps You learn STM32 programming.

peter-wasilewskiPeter Wasilewski 01/09/2016 at 21:170 Comments

Hello !

I can imagine it's been a while since I last wrote, but I'll try to make it up in this entry.

Since last time I've made some major changes. I decided to use ILI9320 lcd ( which

is at my place, and soon 'll be tested), also I'll buy an 2,2" touch panel for this

display. I was very unhappy to make this change in the project, but it was necessary

to keep the watch in good shape. Honestly these nokia's lcd's are slow, have only 8

bit parallel bus, and what is very annoying - almost impossible to see in the sun (

maybe I got the chinnese version :P ). Besides that they support only 24bit/pixel

colour depth and the sizes are 2,4" ( too big for a wristwatch) and 2,0 " ( too

small to make a PCB, and I couldn't find the matching touch panel).

I've also decided to use stm32f429 in bga package as well as the SRAM memory. That means I have to make an 4-layer PCB ( "make" is not the good word - "order" would be better - I'm not crazy :) ). New microcontroller gives me new features such as Graphic accelerator and higher core freqency.

Though I didn't stop creating the firmware. I kept the promise and made a menu with an MP3 player “app”. As You are able to see in the video the songs are picked randomly, using the STM's random number generator. The whole MP3 app is a bit down, but it's going to be fixed soon .

The menu runs on FreeRTOS, and of course Stmwin library is used. In

the video You can see the unbelievable features of this LIb, for instance smooth

scroling, without flickering. The memory fot Stemwin is allocated on external SRAM

and is almost as fast as the internal memory.

Yesterday I managed to run Bluetooth 4.0, and now I'm going to take care of communication between the watch and the smartphone.

One more thing I have to tell You about. That is the Freertos Trace - a very helpful

software while developing a RTOS application. It shows You the timings, priorities

and tasks in graphic way. The demo version is enough for basic purposes.

Now it's time for some pictures and videos ;) .

In the left top corner the original case of the 2.2' lcd ( making the real dimensions like it was 2,4" ), next to it on the right a 2,4" touch panel ( sold with 2,2" lcd ) on the bottom the LCD I want to put, and the 2,2" touch.

comparison of the new display and actual nWatch.

Regarding the video that you're about to see - the colour of the menu is so yellow due to fact that library cannot support 24 colour depth using the MEMDEVICE mechanism, which handles the flickering ( so for now I have to use 16bit/px).

Till next time,