andrea.varesio
Posts: 5
Joined: Wed May 29, 2013 11:06 am

Reading 8bit synchronous data @ 30MHz - interface RPI3 with camera sensonr OV2640

Sat May 11, 2019 5:49 pm

Hi

I am trying to understand whether it is feasable to interface PI with camera sensor OV2640. This sensor has an outpu digital video port providing 8/10 bit synchronous with Pixel clock running @ 30MHz. Reading data at such speed cannot be done in user space.

I am wondering whether the SMI (secondary memory interface) can provideo such feature. But I cannot find hardware specification (has been removed) anyhwere.

RPI3 come with a kernel driver for SMI. I tested it, enabling it in boot/config.txt and the /dev/smi device is created an is working.

But I need hardware specifications in order to understand whether it can work in synchronous mode, or if I can adapt signal with a small fpga to read data directly into RPI.

Can anyone point me to the SMI hardware specification or to similar projects?

Andrea

User avatar
HermannSW
Posts: 1393
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: Reading 8bit synchronous data @ 30MHz - interface RPI3 with camera sensonr OV2640

Thu May 16, 2019 11:16 am

You might install Arduino IDE and then ESP32 support. Sample ESP32->Camera->CamWebServer for ESP32-Eye module (9$ ESP32 inclusive ov2640 camera). You should find the details on how the ESP32 deals with ov2640 camera in this directory:

Code: Select all

~/.arduino15/packages/esp32/hardware/esp32/1.0.2/libraries/ESP32/examples/Camera/CameraWebServer
CamWebServer sample is quite impressive, MJPEG stream to browser, face detection for CIF and below formats, up to 2MP:
https://twitter.com/HermannSW/status/11 ... 8050680832
Image
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://gitlab.freedesktop.org/HermannSW/gst-template
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7141
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Reading 8bit synchronous data @ 30MHz - interface RPI3 with camera sensonr OV2640

Thu May 16, 2019 1:32 pm

But in answer to your original question, no the Pi can not accept a parallel camera interface, only CSI2 (serial) ones.
There are bridge chips available (eg Toshiba TC358746), but getting hold of them and getting them to work can be tricky.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

User avatar
HermannSW
Posts: 1393
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: Reading 8bit synchronous data @ 30MHz - interface RPI3 with camera sensonr OV2640

Thu May 16, 2019 2:53 pm

> I am trying to understand whether it is feasable to interface PI with camera sensor OV2640.
>
I completely forgot about the Arducam USB2 camera shield that I bought together with a OV5642 w/ CS mount lens at the beginning of my work on getting global reset videos from (Arducam) ov5647 camera (v1 camera with FREX and STROBE pins exposed):
Image


You can connect the shield to a range of different OSes, including MS Windows as well as Raspbian.

This is the Raspbian streaming demo I used with ov5642 sensor:
https://github.com/ArduCAM/ArduCAM_USB_ ... aming_demo
Image


There are 20 camera types supported by the shield, including OV2640 2MP.
But the USB2 camera shield (there is a USB3 shield as well) does cost 50$ on uctronics.com.
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://gitlab.freedesktop.org/HermannSW/gst-template
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

Return to “Interfacing (DSI, CSI, I2C, etc.)”