STM32f407 _DCMI with DMA need any external RAM?

[Haresh Prajapati]

Posted on October 25, 2017 at 14:51

Hello All,

I am first time working on DCMI with STM32f4 series micro controller.

We are planing to interface DCMI camera with STM32f407 Micro controller.

Camera Resolution is '2592x1944' and Image size goes up to 512kb ~ 2MB.

Camera module consist of ov5642 CMOS.

We have already interfaced Memory card for storage of data.

Is there any external memory(Buffer) is required while camera image capturing is in process?

Is there any possibility to store image directly in to Memory card over SPI interface?

#dma #memory #stm32f407 #dcmi #ov5642

[Tesla DeLorean]

Posted on October 25, 2017 at 17:41

You'd need to store the image somewhere if you can't process it on-the-fly, SPI to SD Card is going to have woeful performance, SDIO would be significantly better, but even back-of-the-envelope math suggests you aren't going to be able to stuff 14-bit @ 54 MHz onto 4-bit @ 24 MHz, let alone onto a 1-bit interface.

Perhaps look at a FIFO if external memory is undesirable, say AL422B or AL462 for 2K type imagery

http://www.averlogic.com/AL422B.asp

 

[Haresh Prajapati]

Posted on October 26, 2017 at 07:07

Hello Sir,

Thanks for your reply.

I want to use STM32f407 Controller so can you suggest us any kind of FiFo or RAM which is suitable with STM32f407 ?

I am newbie RAM interfacing with STM32f407 micro controller. Can you Provide us good reference on RAM interface with STM32f407 Controller ?

Below are the Camera Pin Specification.

Pin No.

PIN NAME

TYPE

DESCRIPTION

1

VCC

POWER

3.3v Power supply

2

GND

Ground

Power ground

3

SCL

Input

Two-Wire Serial Interface Clock

4

S

DATA

Bi-directional

Two-Wire Serial Interface Data I/O

5

VSYNC

Output

Active High: Frame Valid; indicates active frame

6

HREF

Output

Active High: Line/Data Valid; indicates active pixels

7

PCLK

Output

Pixel Clock output from sensor

8

XCLK

Input

Master Clock into Sensor

9

D

OUT

9

Output

Pixel Data Output 9 (MSB)

10

D

OUT

8

Output

Pixel Data Output 8

11

D

OUT

7

Output

Pixel Data Output 7

12

D

OUT

6

Output

Pixel Data Output 6

13

D

OUT

5

Output

Pixel Data Output 5

14

D

OUT

4

Output

Pixel Data Output 4

15

D

OUT

3

Output

Pixel Data Output 3

16

D

OUT

2

Output

Pixel Data Output 2 (LSB)

17

PWDN

Input

Power down

18

RSV

NC

Reserved

19

D

OUT

1

Output

Pixel Data Output 1(10bit mode)

20

D

OUT

0

Output

Pixel Data Output 0 (10bit mode)