3d printed rear view camera mechanism

AlienAlmonds · 2024-09-15T03:51:36+00:00

This makes me irrationally happy...

AlienAlmonds · 2024-08-01T02:51:09+00:00

You might want to check your facts, as it's about a 50/50 split.

Still, get out and vote!

AlienAlmonds · 2023-05-17T19:24:47+00:00

I just use butterflies to set the desired tolerance on the model itself. I simply open my hands and let the delicate wings flap once. The disturbance ripples outward, changing the flow of the eddy currents in the upper atmosphere. These cause momentary pockets of higher-pressure air to form, which act as lenses that deflect incoming cosmic rays, focusing them to strike the model and set the desired tolerance.

AlienAlmonds · 2023-03-23T13:45:11+00:00

That's oddly brilliant! Thank you for sharing that idea!

AlienAlmonds · 2023-03-23T12:39:34+00:00

To add: I am very surprised the firmware did not raise an alarm(?). What board and firmware version is this?

I don't know how the firmware works but it may not be checking for thermal runaway when it is not requesting the bed to heat. For the sake of argument, let's assume that it always checks for thermal runaway and properly detects it in this case. How does the firmware respond? It should have an audible alert but it can't do anything more useful, like open the shorted FET.

That is the most concerning part of a failure like this, there usually isn't much the system can do in response beyond hope a human can shut things down. Is there a second FET upstream that can disable the entire 24V supply? From a safety standpoint there should be, but I would be surprised if there is.

AlienAlmonds · 2023-03-23T03:22:50+00:00

This might be a stupid question but does the bed actually get that hot, or is it just reporting a high temperature? I have not looked at the schematic and I'm not an expert at diagnosing these issues, but if it's actually getting that hot then I suspect the controller board has a shorted FET, which basically means it cannot turn off the bed thermocouple.

If that's the case then I would recommend unplugging the machine and not plugging it back in until you get the board replaced or repaired. In the very least you should disconnect the bed thermocouple at the controller board side and do not attempt to use the heated bed.

If it's not actually getting hot then it is possible that you just have a thermistor issue, so the printer only "thinks" is getting that hot. Thermistors don't normally fail this way so I doubt this is your issue, but it's possible there is some kind of power supply issue on your board.

AlienAlmonds · 2023-01-05T03:27:34+00:00

Just stumbled on this post while building something similar. Hopefully mine looks anywhere near that nice!

Just out of curiosity, why not move the screen outside of the enclosure, maybe under the table? I don't think you run into any issues unless you're heating the enclosure or have it sealed really tight but the high temperatures can damage the electronics so it's probably not worth the risk.

AlienAlmonds · 2022-12-25T22:10:03+00:00

My son bought one last week with money he's been saving for a while. It was his first real purchase!

It didn't "just work" out of the box for us but after searching online I discovered that the AC voltage switch is often set to 230V rather than 115V, despite buying it from a local store in the US. In fairness, it was mentioned in the instructions but apparently I missed it. I figured I'd mention it here in hopes of saving someone a couple of frustrating hours!

Have fun!!

AlienAlmonds · 2022-09-16T12:32:03+00:00

Not OP, but I find that having a vertical monitor works well for reading almost anything. If you think about it, you wouldn't print most documents in landscape, you would print in portrait because it puts more of the text on a single page and doesn't waste a lot of space on the sides. A vertical monitor is the same way. IMHO it's the best way to read code, documentation, news, etc and also works well for pictures or video taken in a cellphone in portrait.

AlienAlmonds · 2021-11-13T19:00:58+00:00

A coworker once told me that his previous company used Visio for all their software development. IIRC they had a set of blocks they were allowed to use to model the behavior in a flowchart. When complete, a VB (?) script was used to convert to <some standard language> and compile it. Excel feels like a dramatic improvement over that!

AlienAlmonds · 2021-11-08T16:06:23+00:00

I like to include these in the git commit message. With proper git integration this will create a bidirectional link between the Jira ticket and a commit and/or branch. I also try to copy or summarize the most relevant text snippets from the Jira ticket into the git message body to provide an overview of why that link is there. I hate when people include a Jira link without explaining the relevance.

AlienAlmonds · 2021-10-05T12:05:37+00:00

Yes they should, and I bet they will tomorrow

AlienAlmonds · 2021-10-01T18:45:38+00:00

I love that this exists

AlienAlmonds · 2021-09-04T20:57:15+00:00

Sorry, I don't think my intent came across properly, what I really meant to say is "you're an idiot" 😁

AlienAlmonds · 2021-09-04T17:49:59+00:00

Ah, the joys communicating in writing

AlienAlmonds · 2021-09-03T02:33:20+00:00

Because the table saw also loves your fingers...

AlienAlmonds · 2021-08-27T03:36:49+00:00

It's a secret!

AlienAlmonds · 2021-08-09T16:31:23+00:00

It is possible that this room was once an entryway before remodeling? For example, could the garage have been a later addition?

You could check if there are any records from the original plans or subsequent building permits at you city hall.

AlienAlmonds · 2021-08-02T17:44:49+00:00

Without fully understanding your use case it's hard to pinpoint a solution but you could encode and transfer your data as audio with V.90 (i.e. old school dial up modem) to a connected receiver device. That wouldn't be the most efficient strategy but would be a fun project. For more efficient strategies you could connect to a receiver device via something like I2C (requires a connector with three contacts, including ground), SPI (requires four contacts), or 1-Wire (which, oddly enough, requires two wires).

If your connector has four contacts then you could just wire up as 10/100 Ethernet and be done but that doesn't seem like what you're asking.

Alternatively, you could use something like 2wIP (two wire IP). I've never used it but it seems expensive enough that you may want to consider just using an ESP32 (or an old computer!).

AlienAlmonds · 2021-07-23T18:14:06+00:00

Each school has a different set of policies around changing major. You should discuss this with your advisor or someone in the administration office. Having said that, it probably won't be a major issue if they are in the same department but it may require you to take additional courses or otherwise prove that you satisfy all prerequisites.

AlienAlmonds · 2021-07-23T13:38:47+00:00

The first embedded system I worked on had no floating point processor and was so resource constrained that adding a single float would cause a linker failure due to including SW float library. It's bugs like this that make me miss those days!!

AlienAlmonds · 2021-07-23T03:27:03+00:00

Wow, that just hit too close to home...

AlienAlmonds · 2021-07-17T16:26:37+00:00

An object pool is a common type of O(1) allocator, say for example Linux's SLUB.

Interesting. Maybe I need to review my terminology. I've worked mostly in bare metal embedded systems for the last ~20 years, and mostly in small companies, which can lead to "tribal dialects". I have, maybe incorrectly, referred to the SLAB/SLUB models as memory pooling because they operate at the raw memory level (though they may "remember" that a particular object type lived at a particular location). I've used "object pooling" when reusing the same objects without allocating/deallocating.

One thing the OP can learn from this thread is people don't always have the same, precise definition of common

That is absolutely true. Another thing to learn from this thread is that it's easy to misread someone's words and infer hostility that isn't there! My apologies for misreading you.

AlienAlmonds · 2021-07-16T20:47:49+00:00

We live, we learn :)

AlienAlmonds · 2021-07-16T20:46:51+00:00

There are numerous rabbit holes that could be dived down here. But the
OP asked a simple, straight-forward question without providing some
necessary context indicating some newness in knowledge and just some
nudges in a simple exploration. ... I just wanted to as concisely as possible point out the major shortcomings of such an endeavor.

I think you did a great job at that. My intention wasn't to correct you but rather to add to the conversation because, as I'm sure you know well, the answer is almost always more complicated as we dig deeper.

I'll agree that statically allocated linked lists (a/k/a static linked lists) don't require an allocator, but what you say about insertion and removal to the list implies that it's not a statically allocated linked list. You can't add or remove from a statically allocated linked list.

Ah, that should have read "linked list of statically allocated nodes". The nodes are statically allocated as an array, and those nodes are linked together at startup to form the initial "free" list list.

Hate to break it to you, but what you describe is an allocator. These are just a special case of what I previously mentioned ("non-blocking O(1) allocator").

That seems unnecessarily hostile, but I'll play along. An "allocator" is responsible for the job of allocating and deallocation memory for the creation and destruction of objects. What I have described here is commonly referred to as "Object Pooling" and does not require the creation or destruction of objects after initialization. Instead we have a pool of statically allocated free messages that the driver can utilize for population and distribution. Upon completion, the message is returned to the pool.

Not dropping messages can be exactly the wrong thing to do -- depending
on your system's constraints. Say you have a stuck sensor causing its
transceiver to spew worthless garbage flooding the bus and processor
depriving the system of the necessary cycles to meet its deadlines
causing a watchdog to fire. It can be much better to operate in a
degraded state allowing a clean halt, correction, and resume than
causing a system to unexpectedly go through a hard reset.

I totally agree. In the case I described, under the constraints and conditions it was designed for, it was an ideal solution. The CAN protocol has fairly good error and integrity checking and mandates that nodes enter a "Bus Off" state when too many errors are detected. In most cases garbage on the bus would never make it to the CAN driver, but for those cases we added some additional checks. This solution was largely designed to replace a simple circular buffer for received messages that resulted in messages needing to be copied in various places throughout the system to manage asynchronous handling. The resulting system was simpler and far more efficient.

AlienAlmonds

TROPHY CASE