Reverse-engineering a $35 backup camera display (AMT630A) | Hacker News Reader

Reverse-engineering a $35 backup camera display (AMT630A)

github.com

82 pointsmogrinz25 comments

This started because I built a full-size Robby the Robot suit and discovered I couldn't actually see out of it (https://youtu.be/gAHd46ErNA8?si=-iOwbobp4trPXdGB)

I bought a $35 backup camera/display to solve that problem, then discovered that the display contained an AMT630A video processor with a surprisingly capable OSD system. That sent me down a rabbit hole of I2C probing, firmware dumping, register tracing, custom graphics, bitmap formats, hidden factory menus, and eventually figuring out how to use an ESP32 to generate a programmable HUD over the live composite video.

I ended up turning what I learned into an Arduino library, which I've released on GitHub. It supports built-in and custom fonts, multiple OSD windows, 16-color bitmaps, palettes, transparency, and animation. It can also be used with composite video sources other than the camera.

The library and code are here: https://github.com/mogrinz/AMT630A You can also install directly from the Arduino IDE Library Manager (search for AMT630A)

Hah, the video is more exciting than the readme, IMO an image of the robot in the readme would be attention-getting.

Would "rear view mirrors" help navigation in the suit? So 2 extra displays that would give you a view of what's over your shoulder, like on some cars nowadays (for example): https://www.carscoops.com/2022/02/heres-what-you-wanted-to-k...

The setup I bought only has one camera but the AMT supports up to 3 separate composite sources (I did not add switching to the library yet b/c I couldn’t test this). It looks like split-screen is supported also. For now, I am adding some simple sensors to the back of the suit and triggering an on-screen pop-up when something is behind me

Hm. Have you thought about using a backup camera? =)

Holy smokes I like that. Maybe it will catch on, I dunno.

Cameras are rear view mirrors? Audi e-trons have them, they're also available as option on Hyundai Ioniqs. But apparently it's unlawful to not have physical side mirrors in North America...

Neat! Can you add the pictures of your setup? Display, soldered wires, some overlays?

(sorry if they in the video - I generally don't watch the videos before reading the text first)

the video goes into a lot of this. it is far above average YouTube quality.

Tracking-free YouTube link: https://youtu.be/gAHd46ErNA8

@dang Could HN remove source identifiers from links by default?

About 12 minutes into the first vid, the thought struck me: How will the EMT's react to a guy stuck halfway inside a Robby the Robot suit?

"can we legally post the teardown video of this to hacker news?"

Heads up, your youtube link has a tracking ID in it that is bound to the account/device you shared the link from.

This video on the device itself (from the readme), not about the robot suit itself.

How I See from Inside Robby — AMT630A Heads-Up Display https://www.youtube.com/watch?v=0eQ94DHOay0

Thanks! I’ll fix that

Still not fixed :(

Replace it with: https://youtu.be/gAHd46ErNA8

Yeah, I didn’t realize there was a time limit on edits, and I was well outside of it

nocash behind no$gba and no$nes has an article on this as well https://problemkaputt.de/amt630a.htm

Classic bit of reverse engineering. I love how detailed your readme is.

Title nit: "backup" means a second copy, "back up" is the verb phrase for moving backwards. Verb phrases get hyphenated for clarity when used as adjectives immediately preceding a noun. So this should be "back-up camera", not "backup camera".

"backup camera", no hyphen or space, is at least popular enough to have a wikipedia entry.

https://en.wikipedia.org/wiki/Backup_camera

it is also used very regularly elsewhere, like government sites: https://www.nhtsa.gov/vehicle-safety/driver-assistance-techn...

or legal advice sites: https://thelegalguide.org/are-backup-cameras-required-all-ca...

or news sites: https://abcnews.com/US/cars-us-now-required-backup-cameras/s... https://www.reuters.com/article/business/consumer-groups-sue...

or automotive magazines: https://www.autoweek.com/news/a1892066/feds-backup-cameras-a... https://www.caranddriver.com/car-accessories/g44411856/best-...

it's safe to say that "backup camera" is perfectly acceptable.

I think this may be a case of language evolving/devolving and quite possibly an Americanism.

I'm British and to me backup means having a reserve or spare ready to use. You have a battery backup on your servers to step in when there is a mains problem, a photographer will have a backup camera, you backup you files regularly etc.

We would call this a reversing camera, for when you reverse your car using the Reverse gear. You can back into a parking space, or even just back up a little bit into a better spot.

One thing I'm seeing which irritates me is people are starting to call backing singers backup singers. They are not a backup the the lead singer, that would be an understudy, they are supporting like the backing on picture.

> One thing I'm seeing which irritates me is people are starting to call backing singers backup singers.

Rolling Stone magazine has been using the phrase "backup singer" for a genuinely long time.

https://www.rollingstone.com/music/music-news/dylan-gets-gos...

Fwiw, I used the same phrasing in my title as the product I bought on Amazon. Most of these are made (and packaged) in China: https://www.amazon.com/s?k=backup+camera A search for “reverse camera” only returns “backup camera”s

At least the naming convention has redundancy, unlike most people's actual backups

Backup camera is cromulent. Reversing camera is also cromulent.

A reversing camera is handy for people on one side pond when they take their estate down to the tip to chuck out a load of rubbish.

Backup cameras are useful for people on the other side of the pond when they take their station wagon to the dump to get rid of some trash.

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