User Manual

ArduCAM Camera Shield Software Application Note
www.ArduCAM.com
12
make the frame buffer overflow.
5.3 Short Video Capture Mode
Use the same command as the Multiple Capture Mode. When the value bit[2:0] equals to 7,
the ArduCAM will continuously capture the images until the entire frame buffer is full. User can
save the captured MJPEG to AVI files to create short movie clips.
5.4 Single Read Operation
It is basic memory read function which start a single read operation and read a single byte
each time. By sending command code 0x3D to start a single read operation, a single byte is read
out from the frame buffer.
5.5 Burst Read Operation
It is advance capture function which can read multiple bytes out of the frame buffer by just
sending a single command code 0x3C.
Please note that for these hardware platforms (ArduCAM Shield Rev.C+,
ArduCAM-Mini-2MP, ArduCAM-Mini-5MP) the first read byte should be ignored in the first read
transaction, because it is a dummy byte. In the following read transaction, the first byte read is the
last read byte in the last read transaction, it is very important. And do not use other SPI command
between burst read transaction. Detail timing can be found from Figure 5.
CMD 0x00 0x00 0x00 0x00 0x00 0x00 0x00
SCLK
MOSI
CSn
MISO
Command Phase
Data Phase
dummy
D0 D1 D2 Dn-2 Dn-1 Dn
CMD 0x00 0x00 0x00 0x00 0x00 0x00 0x00
Command Phase
Data Phase
Dn+1
Dn+2 Dn+3 Dn+4 Dm-2 Dm-1 Dm
First read transaction
following read transaction
Figure 5 Burst read timing diagram 1
For hardware platforms (ArduCAM-Shield-V2, ArduCAM-Mini-5MP-Plus), you don't need
to worry about the first byte. Detail timing can be found from Figure 6.
CMD 0x00 0x00 0x00 0x00 0x00 0x00 0x00
SCLK
MOSI
CSn
MISO
Command Phase
Data Phase
D0 D1 D2
Dn-2 Dn-1 Dn
CMD 0x00 0x00 0x00 0x00 0x00 0x00 0x00
Command Phase
Data Phase
Dn+1
Dn+2 Dn+3 Dn+4 Dm-2 Dm-1 Dm
First read transaction
following read transaction
D3
Figure 6 Burst read timing diagram 2
5.6 Rewind Read Operation
Rewind read is useful for some application that need access the same pixel data multiple
times. By sending the command code 0x84 and write ‘1’ to bit[5] in the data phase, it will reset the
memory read pointer to ZERO. Then user can read the image data from the start of the memory.
5.7 Low Power Mode
For some battery powered device power consumption is very important. There are two levels
to achieve low power mode, user have to combine these modes according to their own power
strategy.
5.7.1 Power down the sensor circuit