Question: I've incorporated Hotwire into my latest Rails 6 app. The Hotwire/Turbo portions are working great, but I have a plain user form that I don't want to use Hotwire/Turbo for. Currently, all form submissions are hitting `format.turbo_stream {}` in my controller , but I want this particular form to hit the `format.html {}` block instead. I noticed that the `Accept` header on form submission requests automatically includes `text/vnd.turbo_stream.html` now, but I'm not sure how to remove this.

The form is not wrapped in a turbo\_frame\_tag; there is no Turbo anywhere on the page, and it looks pretty standard:

```
    <%= form_with model: @user do |f| %>
      <%= f.file_field :avatar, class: "file-input", id: "avatar-input" %>
      <%= f.text_field :name, class: "input wide", placeholder: "Your name here" %>

      <%= f.submit "Next", class: "button-next-submit" %>
    <% end %>

```

How do I force this change on a per-form basis? I previously thought that adding the turbo tags was how you change the behavior / the Accept header, but I see now that once you add a `format.turbo_stream` block in your controller method, the form begins to prefer it.

Answer: 
First thing, you should start with your calculator and punch in the numbers to see what you get.

For example, a 1920 x 1080 pixel image with 1 bit per pixel is ~253KB of data.

If you're handling large image files, a microcontroller isn't going to cut it. Most microcontrollers have less than 1MB of memory total, if that. The [Raspberry Pi Pico](https://www.raspberrypi.org/documentation/rp2040/getting-started/#board-specifications) for example has 264KB of memory, a fairly generous amount, and that can barely hold a bitmap image that size.

You need a more robust processor. A Raspberry Pi has 2GB+ of memory and can handle images that scale at 24-bit color depth. 1920 x 1080 x 3 bytes per pixel is about 5.9MB of data. Totally manageable on a system with >32MB of memory.

Remember, microcontrollers excel at performing simple tasks like driving a keyboard, servo motors, communicating with sensors and such, and are really bad at doing intensive processing. The Pico's CPU runs at 133MHz, that's it. There's only so much you can do with a few watts of power!

You'll need a full CPU to do image processing, or even better, leverage the GPU elements on a system like the Pi to do that more efficiently, something no microcontroller is ever going to include.
For this type of task, I would recommend starting with something over-powered. You might be able to fit it into a small low-power microcontroller, but it likely won't be worth the effort. Try something on the order of the various Raspberry Pi MCUs.