High frame rate recording to uSD

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zaca
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Joined: Wed Oct 02, 2019 12:49 pm

High frame rate recording to uSD

Postby zaca » Wed Oct 02, 2019 2:12 pm

Hi OpenMV forums,
We are looking to record to the uSD with the OpenMV H7 outfitted with the Global Shutter Module with as high of frame rate as possible. It would be awesome if we could record to the uSD at 180FPS at QQVGA resolution. We have gotten the camera to easily go this fast within our project requirements but are having trouble getting this frame rate to record to the uSD. The uSD card were are using is the UHS speed class mark 3 capable of 30MB/sec. What is the max FPS we could record and what file type would you suggest(gif, image reader, or Mjpeg)? Mjpeg would be preferred but the most important requirement would be high frames per second. If the uSD recording method will not be able to achieve this, does another recording method exist that can meet this requirement.
Thanks
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kwagyeman
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Joined: Sun May 24, 2015 2:10 pm

Re: High frame rate recording to uSD

Postby kwagyeman » Thu Oct 03, 2019 2:28 am

Hi, the camera can't record at that speed. We don't have the system architecture to allow it. It doesn't really matter what the SD card max speed is. We don't have a ram fifo to decouple the cards random write hiccups nor do we have the high speed 1.8v I/Is for the highest signaling speed.

There's really not a way to record the image data. Maybe the output from an algorithm. I'm sorry, but, our system isn't designed with this ability.
Nyamekye,
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iabdalkader
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Joined: Sun May 24, 2015 3:53 pm

Re: High frame rate recording to uSD

Postby iabdalkader » Thu Oct 03, 2019 2:15 pm

Hi, the maximum FPS you can get with the current cam is 100FPS @ QQVGA with a class 3 card formatted to exFAT. Note we're going to release a new revision with an SDRAM on board, with that we could buffer writes to RAM and then transfer to SD.

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