Software to update and run a small electronic-"picture frame"-esque Lego "construction block" compatible TV
- Uses a 1.8in TFT LCD screen (JT-D1800 ?) with ST7735 controller
- Data is stored on a Windbond W25Q128FV SPI flash chip
- Loads TFT configuration + number of image + number of bytes per image from flash data
- Data is spread according to the flash memory sectors optimized to the bytes-per-image length
- Automatically switch to next image after about 5 seconds
- Supports Next and Previous switches
- The PIC16F88 assembly files of the actual firmware
- Includes a few quick macro for 16bit operations and wrapped ASM branching
- Both methods to send and receive data are shown with conventionnal loop structure and also the faster unwrapped version
A simple image library style editor to load and adjust image file to fit the TFT screen and then convert the resulting "library" in a pure flash data file readable by the TFT screen.
- Support Load library, Add library (to current library), Save Library and Export data.
- Basic list of image to load, crop/resize and change position in list
- Export to tightly packed raw data
- Convert image data to different RGB color scheme.
Software interface to use the FTDI UM245R as a software SPI interface to transfer the data file into the SPI flash chip.
- Support Windbond W25Q128FV 128mbit SPI flash devices and basic support of SST25VF016B
- Write the data according sector boundary to simplify flash chip ereases and PIC loading (i.e. 32K or 64k)
- Use the FTDI UM245R USB interface as a software emulated SPI host
- Load TFT Data Manager raw data and flash expanded data in windbond chip with proper sector alignment
The "block" is custom machined on a Taig lathe using only DRO for reference and a custom cutter for the studs.
Top and Bottom plates were actually test parts that got fused togheter with a casting of polyurethane plastic then hollowed-out by the same milling setup.
Backplate is the actual SMT PCB
- Uses CMOS 3.3V chips for MCU + EEPROM + Display
- Home-made PCB with laser printer transfer sheets
- Diode used to prevent accidental introduction of batteries in reverse oder (project is intended to be used by childen) so 4x1.5V batteries are required in the pack
- Integrated 3.3V LDO regulator
- PIC16F88 with internal 8MHz osc. Also works with external 20MHz osc by adjusting the internal timing and adding external components but turned-out to only add un-necessary complexity on the PCB witout much impact on usability
- 128Mbit/16Mbyte flash contains either 511 images in RGB444 (actually capped to 255 due to 1 byte num_image variable) or 255 RGB666 (actually RGB888 because lazyness) images
- Block Schematics
- PCBs of controller and TFT backplate
- Schematics and PCBs are available as PDF in the repository's /Schematics/ folder
