Image Capture Using A Microcontroller

[alopes]

Morning! i'm making a school work related with image capture using a microcontroller.
This work is totally new for me, reason why i'm having some difficulties. It consists in the using of a digital camera with 640 x 480 pixels resolution (VGA), that reads 30 frames per second. The microcontroller PIC24f is connected with a SD card where the data is stored.
I ask if it is possible to record directly the data in the SD card or if it is necessary a memory RAM connected to the microcontroller and what type?
I really appreciate any clarification.

 

[Papabravo]

There are several options for the SD card interface. Which one did you have in mind?

640 x 480 = 307,200 pixels
307,200 pixels/frame * 30 frames/second = 9.216 Megapixels per second
If each pixel takes 24 bits that is 221.184 Megabits/second

I think you have no prayer of capturing data and recording directly on an SD card at that rate. I could be wrong, but I think 80 Megabits/second might be a practical upper bound.

 

[Ubergeek63]

I think you have no prayer of capturing data and recording directly on an SD card at that rate. I could be wrong, but I think 80 Megabits/second might be a practical upper bound.

According to **broken link removed** the maximum guarenteed sustained data read rate is 48Mb/S

Dan

 

[Papabravo]

Well 20 MHz is about the max for an SPI interface which the SDI card supports, and I multiplied by 4 to get the upper bound for the 4-bit wide transfers. I did say it was an upper bound, and it seems that the actual upper bound is a bit lower. That is science and technology for ya.

 

[alopes]

thank you for your replys! the camera that i use is the VS6724 from ST, each pixel is 16 bit or 8 bit, depending of the quality we want! I ask what microcontroller should I use and if I need to use a FIFO between the camera and the microcontroller? thank you.

regards

alopes

 

[Nigel Goodwin]

thank you for your replys! the camera that i use is the VS6724 from ST, each pixel is 16 bit or 8 bit, depending of the quality we want! I ask what microcontroller should I use and if I need to use a FIFO between the camera and the microcontroller? thank you.

Try working out how much data that will create, and how fast you can shift it with a PIC, or how fast you can store it in an SD card.

 

[alopes]

the data output from the camera will be at a 1.3MB/s. I have been searching for microcontrollers, the PIC32 will resolve my problem? or the ARM9? I still have to use RAM to be able to store d video file in the SD card?
thank you

aplopes

 

[Ubergeek63]

the data output from the camera will be at a 1.3MB/s. I have been searching for microcontrollers, the PIC32 will resolve my problem? or the ARM9? I still have to use RAM to be able to store d video file in the SD card?
thank you

aplopes

how do you figure that? that is the tiniest fraction of the image data rate.

 

[Nigel Goodwin]

how do you figure that? that is the tiniest fraction of the image data rate.

Perhaps it includes an MPEG encoder?.

 

[radhakrishna dasari]

if you want to capture an image..you are just reading a single frame from the camera...that makes it just 300 kb...
look for a snapshot command in the datasheet of your camera module..