FM VERİCİ

As inspired by Simple SD Audio Player by ChaN, this project uses Microchip's PIC18F2550 to read RIFF WAVE files, and display some file information on the N6610 LCD; And then it will play the audio itself through PIC's PWM with a simple RC filter on the output pin. The hardware actually comes from my previous project, and I just attached a ready-made audio amp (w/ speaker) for the demo.
Schematic:
Due to PIC's peripheral limitations, I only set the PWM frequency to 187.5kHz and not the 250kHz carrier frequency originally used by ChaN, because it's the maximum PWM frequency than can still get an 8-bit resolution of the duty cycles (=48MHz/256). It is also possible to use R-2R ladder in stead of (low-pass) filtering the PWM output since there still enough unused digital output pins for this approach.
On the software part, I wasn't able to make a good data buffering as good as what ChaN did. It's noticeable with WAVE files with higher bit-rates (=SampleRate*NumChannels*BitsPerSample). Nevertheless, it can still support up to 48kHz sampling rate, but with only Mono channel and 8-bits/sample resolution.

demo video:


Source code(PICC-18) with and without LCD: PIC18 SD WAV Audio Player

My on-going project: currently porting the code to STM32F103RB for additional features.

Some useful software (shareware) tools:
TextAloud - Text to Speech software
Switch Sound File Converter-multi format audio file converters

It is similar to my first PIC SD BMP Reader , and almost the same circuit except for the LCD. This time I now use a Nokia 6610 LCD. The LCD is capable of displaying 4096 colors, but for code simplicity I just operate it at 8-bit (256 colors) resolution.

Diagram:
This project is capable of reading bitmap file using common format (24-bit per pixel), with size (width and height) equal to or less than 132 pixels at both side.

demo video:



Source code + diagram: PIC18 SD BMP Reader 2.rar


similar project at Hack-a-day: How-to: Digital picture frame, 100% DIY
-it uses PIC24FJ64 in stead of pic18f2550

This project uses Microchip's PIC18F2550 and Nokia 3310 LCD to read and display images from BMP files on the SD/MMC cards. Although the display itself is monochrome, it still supports 24-bpp (bits per pixel), 8-bpp, 4-bpp, and 1-bpp (monochrome) Bitmap files (*.BMP) with size of 84x48 pixels. It uses the Petit FAT File System Module by ChaN.

Diagram and simulation:
Actual circuit:


Demo video:


forum link: Petit FAT File System (w/ Proteus ISIS simulation)

Source code(PICC18) + simulation(ISIS) + others: PIC18 SD BMP Reader.rar

references for BMP file format:
Wiki BMP file format
atlc.sourceforge bmp format
MSDN Types of Bitmaps

The original source code for this project is copied from Martin Thomas' Simple STM32 Digital Picture Frame

The application reads picture-files in standard Windows BMP-format from a SD-Card and shows them on a 2.8" color-LCD-module (320*240 px).

The application also uses the FAT File System Module by Chan, on which M. Thomas ported to work on STM32 SPI interface. Additional information about this project can be found on the link above.


Some of the minor modifications I made were:

• I've modified the LCD driver so that it will work on my unit. My unit got the ILI9320 LCD controller.
  
• I didn't utilize the USART interface (but this can be easily enabled in the code). In stead of sending the "information" through this interface , some of them are being displayed on the LCD itself (e.g. bitmap filenames).
  
• I've enabled the two push-buttons on the board. The first one toggles between "Play" and "Pause"; and the other one is to "Restart" the "slide-show" from the beginning.
  

demo video:


Modified Source Code (Keil RVMDK + uVision 4): Digital Picture Frame.rar