Messages

1

TinyDuino Processors & TinyShields / Re: Taking and saving video to SDCard

« on: May 21, 2019, 01:04:51 PM »

Hi Nefariis.  That sounds like an interesting project, especially considering that there is 32KB of total SRAM available to the processor of the TinyScreen+ or TinyZero.  A single 16-bit 160x120 QQVGA camera frame will use 38,400 bytes of RAM (160x120x2 bytes).
This won't fit in whatever is left of your 32KB of RAM with the app loaded.  So recording video with this board will require writing partial frames.

Thus you will be working with frame blocks.  Maybe these blocks could be compressed slightly with a very lightweight compression function to use less bandwidth, e.g chroma sub-sampling.  At 48Mhz you will have ~3.2 million CPU cycles per frame to play with (ignoring any waits for I/O, etc).
Alternatively there are cameras that can do various types of compression for you, chroma sub-sampling, M-JPEG, h.264, etc.

The data rate for uncompressed 16-bit 15fps QQVGA will be 562.5 KB/s.
Overall the SPI-interfaced microSD card will have to be able to maintain the block write rate otherwise you will lose frames.

This reference design might help with some of the work: http://www.ti.com/tool/tidm-tm4c129camera

2

New Product Ideas / TinyScreen+ compute module

« on: October 16, 2017, 12:30:18 PM »

I would really like to see a bare-bones TinyScreen+ board with just the processor; the same layout as the current TinyDuino but with the Atmel SAMD21 (or maybe a Cortex M3 or M4?).  This would give us a board for more CPU/RAM intensive projects as well as 256KB of Flash memory. 

So really this product *almost* exists - it could simply be the current TinyScreen+ without the 96x64 pixel OLED and the four input buttons.

3

New Product Ideas / Re: TinyMegaDuino

« on: October 15, 2017, 06:08:32 PM »

For me the biggest issue is SRAM - 2KB is just not enough these days, and the 32KB of Flash memory is limiting.  The 8KB SRAM of say the ATmega640 and bigger Flash memory of 64KB would be a very welcome option.  I would buy two just to celebrate!