failed to build true-frame-rate example

[fragrama17]

I found this project very interesting and kind of related to what I am trying to develop here.
I am trying to build the true-frame-rate example running
cargo build --release --example true-frame-rate --target armv7-unknown-linux-gnueabihf --features="examples",

but I get 5 errrors as shown below:

"
128 | Clb: mlx9064x::common::CalibrationData<'a>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in find_frequency

error[E0277]: the trait bound Mlx90641Calibration: MelexisCamera is not satisfied
--> mlx9064x/examples/true-frame-rate.rs:44:28
|
44 | find_frequency(&mut camera, num_frames)?
| -------------- ^^^^^^^^^^^ the trait MelexisCamera is not implemented for Mlx90641Calibration
| |
| required by a bound introduced by this call
|
= help: the following other types implement trait MelexisCamera:
Mlx90640
Mlx90641
note: required by a bound in find_frequency
--> mlx9064x/examples/true-frame-rate.rs:127:10
|
114 | fn find_frequency<
| -------------- required by a bound in this function
...
127 | Cam: mlx9064x::common::MelexisCamera,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in find_frequency

error[E0277]: the trait bound I2cdev: CalibrationData<'_> is not satisfied
--> mlx9064x/examples/true-frame-rate.rs:44:28
|
44 | find_frequency(&mut camera, num_frames)?
| -------------- ^^^^^^^^^^^ the trait CalibrationData<'_> is not implemented for I2cdev
| |
| required by a bound introduced by this call
|
= help: the following other types implement trait CalibrationData<'a>:
Mlx90640Calibration
Mlx90641Calibration
note: required by a bound in find_frequency
--> mlx9064x/examples/true-frame-rate.rs:128:10
|
114 | fn find_frequency<
| -------------- required by a bound in this function
...
128 | Clb: mlx9064x::common::CalibrationData<'a>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in find_frequency

Some errors have detailed explanations: E0107, E0277.
For more information about an error, try rustc --explain E0107.
error: could not compile mlx9064x (example "true-frame-rate") due to 5 previous errors"

Since it's using the I2CDev library, I supposed I could have run it on linux;
on which platforms is possible to use this crate ?

[paxswill]

Sorry, missed this until now; the two examples (true-frame-rate and terminal-temperatures) are meant to be built on Linux, and I tested it with Raspberry Pi 4Bs and BeagleBones (Black and Green specifically). It's been a bit, but I think I also used this on an nrf52840 (but it's also been three years since I've touched this project; I should get around to finishing it...).

Looking over your project I have a few comments:

• I can confirm that these cameras can run at all frame rates advertised by Melexis; there's just really tight timing for the higher frame rates. I documented the max refresh rates for each access pattern and I2C bus speed in the FrameRate docs (and there's a LibreOfice spreadsheet in the repo with the calculations behind that). I also was able to reach all of these using Linux on both SBCs I mentioned above (the RPi takes some config.txt weirdness IIRC to run I2C at 1MHz IIRC).
  • It should take ~0.5ms to read a single register at 100kHz (2 bytes being read + 4 bytes of transaction overhead (start write, send 2 bytes, start read) and each byte has an extra clock cycle for the I2C stop bit, so 54 clock cycles); 150ms is something somewhere in the stack is sleeping or something.
• I highly recommend a cheap logic analyzer for debugging. They should be available for <20 USD from various online shops, then hook it up to Sigrok and you can see exactly what's going on with your I2C bus.
  • Related, that's why there's the true-frame-rate example: these cameras sometimes run a little fast or slow, and since we're trying to keep within the time budget for processing each frame it's a bit maddening when the camera doesn't exactly line up to when you expect the next frame to be ready.
  • If you're using something other than an SBC with an external I2C adapter, it looks like there might be some weirdness with some of those adapters and dotnet: IoT I2C, Ft4232H Write-Read transaction with only new start condition, no restart condition dotnet/iot#2352

[paxswill]

It might also be I need to update it for some embedded-has updates that have happened since then :/