EOS 1200D (Rebel T5): counter results and traces

Hi, me again. I tested my EOS 1200D, and wanted to report back:

tldr: EOS 1200D (Rebel T5): confirmed 0x1001 counter, 0x1015 idk, nothing maybe, BUT cache is disturbing the results, power circle needed!

Summary

I tested an EOS 1200D using two sequences of viewfinder and liveview exposures:

• MPU 0x1001 tracks still exposures exactly after a full camera power cycle
• MPU 0x100b advanced exactly as expected
• MPU 0x1015 always returns ten ff bytes (thanks AI!) and should be treated as unavailable rather than decoded as 65,535.
• But most important: Updated values did not become visible in the first sequence until the camera was switched fully off and on. USB reconnection alone was not sufficient.

Tests

The first sequence was performed without a full power cycle between readings. All three readings remained unchanged:

After fully powering the camera off and on, MPU 0x1001 showed 14,841. This was an increase of 19 over the original baseline although 20 frames had been attempted. Maybe I miss counted here.

The second sequence used full camera power cycles so updated values would be committed and visible:

During the 10-frame live-view burst, the camera reached or approached its buffer limit and paused. The mirror have returned during that delay. That could account for some of the 3 additional changes at 0x100b, but not 100% sure here.

Test data

I can attach the before/after trace JSON files for all tests if you want.

Start by reviewing the listed before/after trace JSON files for both test sequences and compare readings across USB reconnection and full power cycles. Investigate how the counter handles unavailable 0x1015 data and cached values; done means the observed counter and trace behavior is understood and the required handling is documented or agreed.