14: Working code!

After a lot of head scratching and a fair amount of tweaking the code has finally been beaten into  a working form. Because the hardware isn’t yet finished I have to capture the image by moving a camera with a long shutter speed across the board.

Colours are a little off, only have the boards LEDs were captured and a couple of pixels are dead but aside from that…working
What the earth looks like while static…a random blur of colour equating to a blueish white

The captured waveforms below show that the read/write cycle takes currently takes about 22.5% of the time available in a cycle. Therefore we could theoretically handle a frame rate almost 4.5 times higher at our current rate of 12 fps (not particularly useful) OR a resolution about 4.5 times greater. This would mean that we could potentially reach a resolution of 1920×1080 (much more useful!).

One whole image read write cycle (time high is idle)
Idle for 35.2us out of every 45.4us or approx 77.5% of the time
One line being written to and one line being read from SDRAM takes 10.2us of every 45.4us or 22.5%
I noticed the LEDs and drivers got quite toasty so I had a look on my thermal camera. The temperature measurement suggested the drivers were running about 70 celcius (at peak current sink)

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