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Adding an i2c camera to metawear?

allanjohns92allanjohns92
in Hardware
Hello, I was planning on using the metawear to make a small wearable camera, which would transfer images or video from the metawear to the smartphone through the BLE connection.

Is it reasonable to expect that this could be done with a compatible i2c camera such as this, once the i2c support is published in the API?  Of course, transfer rates could be insufficient for high qualities, but is there any reason that image transfer wouldn't be possible once the support is published? 

Thanks very much,
Allan

Comments

  • LauraLaura
    When we worked with a 96x64 OLED and uploaded graphics to the display using BLE you had to wait about 3 to 4 seconds before the photo transfer finished. The short answer is BLE is not fast, it is roughly 5KBps and that might not be good enough for your product.
    As far as I2C support it is coming so there's no reason you can't "hook up" this camera. However the camera has VERY specific power needs I see from the datasheet:
    Power supply : 2.8+/-0.2V or 2.5+/-0.2V (Sensor(photo diode), I/O) and 1.5+/-0.1V(Sensor(A/D converter), Digital)
    So you will have to address this properly with additional power/battery circuitry.
  • allanjohns92allanjohns92
    Thank you for your response Laura. On the bluetooth website it says ble is capable up to 1Mbps in the technical details http://www.bluetooth.com/Pages/low-energy-tech-info.aspx. In your experience transfer on the metawear is limited to 5KBps? Is this a limitation of the chip on metawear?
  • LauraLaura
    @allanjohns92. 
    It is not a limitation of Metawear; it is the BLE 4.0 spec.
    First of all you wrote 1 Mbps (1000000bps) which is bits per second and I wrote 5KBps (5000*8bps) which is kilobytes per second. Second think about the overhead of packets versus raw data transfer rates; a lot of the BLE packets contain a lot more information then just your image data such as UUID, length of data, flags, device name...
    Just some stuff you should think about.
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