Image capture

A project log for Tiny Wireless Capsule Camera

A tiny wireless capsule camera for medical imaging or space-constrained environments

ryan-baileyRyan Bailey 02/07/2017 at 22:430 Comments

One of the bigger challenges recently has been devising a way to capture output from the camera efficiently without relying on the DCMI interface available in other STM32 devices. One of my goals from the beginning was to avoid resorting to BGA or extremely fine-pitch parts. The idea was to keep board design and manufacturing relatively simple and cheap. Unfortunately, I have not found a DCMI-capable part with a sub-10mm diameter in a non-BGA package.

It is tempting to switch to something like the F407 or F429 (as found in the OpenMV). For now, I plan to forge ahead with the following strategy:

Image Capture Block Diagram

Much credit is due to the following article (link) that outlines how to capture data using DMA triggered by a timer in input capture mode. ST also has a decent app note (AN4666) discussing general-purpose synchronous parallel data transfer that proved fairly helpful.

Full image capture should be available soon - there are still some kinks to work out with camera configuration.