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by ColdHeat 1253 days ago
Hello, author here. Happy to answer any questions!

My apologies for the downtime, I wasn't expecting much traffic today since I submitted the post to HN yesterday but I've started scaling my server now!

13 comments

Love this story. I did something similar with a website. Previous owner took it down, bought the domain from him and it organically grew to over 1m users per month with the same exact functionality.

I wouldn't discount your ability to bring this back to market. Would consult a lawyer to see what implications taking over the branding and APIs have. But clearly this has a big market.

I would really like to read more of this story. E.g. what did you do differently, did the original owner ever get in touch with you after it grew, stuff like that. Only if you can, ofc!
I just want to say that I love that you did this. You have great skills and you used them for good. I've never seen such a clearly white-hat hack :)

People's stuff will work again thanks to you and you should feel great about it!

Thank you for the kind words! Made my morning!
I'll ask the same question as asked by @js2 below:

Once the new server was up, did any signs from the field connect to it?

Do you know how many signs are out there actively looking for the mothership?

Here's my reply to him from https://news.ycombinator.com/item?id=34328461

> Good question! No signs connected to the server until I reached out to some other sign owners to try out my instructions.

I do not know how many signs are out there. I imagine most people would have just unplugged their sign after the company's API vanished since any data would be stale and useless.

Love the story! At one point, you are asking about the purpose of the giant hole in the backside of the display: The most plausible explanation is that, it is to allow air circulation within the device to prevent overheating.
Another explanation that I saw [0] was that it was for people to pop the back panel out. I think this is the most likely explanation but it didn't occur to me while working with the sign. I feel like a little notch would have been more appropriate for an actual product.

[0] https://hackaday.com/2023/01/09/iot-archaeology-leads-to-api...

That particle board material would crumble too much if they used a notch for removing the back. I've seen other items in similar cases with the exact same drilled hole in the back cover. Many used staples to hold the back cover on as wood screws tend to damage the (other) particle board used to make the sides. The "designers" probably used it because they had some other item at home (stereo, TV, loudspeakers or clock-radio).
In a retail or home setting, you can mount the sign on a wall and route electrical wiring through the hole for a flush fit.
Why would you call it a good idea?

Even your calculations are way too optimistic.

Giving it little thought, I can say that NYC would have at best 10k sales of this item. In total... including any knockoffs.

The product may have scaled to be able to sell to London, Paris, Tokyo, Soul, Beijing, Shanghai, Hong Kong and Singapore. But this is the total addressable market for this item.

Let's say you have 2 engineers in US working on this full time - that's 500k in salaries(that includes all associated staff).

In NYC you would be able to charge $300, but no other major metro area has that kind of disposable income. In London the max price would be $170, Paris and others - $150... And boom, you can't even make a product to cover development costs.(not to mention any operating costs)

Cool art project and commercial viability clash perfectly here. This item is at best - an art piece, that should cost as such($3000+).

> in NYC you could charge $300

That's 2 days of median disposable income.

For comparison:

San Francisco, U.S. - Disposable income after rent: $4,710

Zurich, Switzerland - Disposable income after rent: $4,626

Chicago, U.S. - Disposable income after rent: $3,298

Boston, U.S. - Disposable income after rent: $3,188

New York City, U.S. - Disposable income after rent: $3,157

Sydney, Australia - Disposable income after rent: $2,615

Melbourne, Australia - Disposable income after rent: $2,485

Oslo, Norway - Disposable income after rent: $2,342

Copenhagen, Denmark - Disposable income after rent: $2,285

Wellington, New Zealand - Disposable income after rent: $2,075

Depending on your list and method, New York could be 44th on global purchasing power index:

https://www.numbeo.com/quality-of-life/rankings.jsp?title=20...

Or 15th:

https://defence.pk/pdf/attachments/screen-shot-2019-11-27-at...

Anyway, "no other major metro area has that kind of disposable income" seems inaccurate.

> Let's say you have 2 engineers in US working on this full time - that's 500k in salaries(that includes all associated staff).

USA, the land of start ups!

Sharp mind and entertaining writing!

I've had a few projects like this where I list out the BOM then go for 'reasonable business success profit' and scratch my head at exactly this line:

> At even just 60k per founder, with the profit per sign sold being maybe $400, you would probably need to sell ~600 signs at full price per year to create enough revenue to run payroll.

Hardware is an exponent to the value of the internal reward, but the root of all business profit. We need a better funding mechanism for this style of development - more like the hardware lifecycle - wasn't Bolt doing something like that?

Just curious what made you come up with at least $30 per LED panel, as these should run you about $10 in bulk.
I had found some tweets by the company where they talked about using an Adafruit panel that was $40. The price on Amazon was about $30 so I figured I would go with the lower price. They may have switched to a lower cost panel but my guess is that didn't happen.

EDIT: Here is the specific tweet: https://twitter.com/NYCTRAINSIGN/status/926106932573810688

The generic name for these panels are "HUB75", based on the interface they use for driving them. I can confirm, these are $10-15/ea in small quantities on sites like Aliexpress. But you're likely right, they were probably buying retail from Adafruit.
"HUB75" refers to the 16 pin connector and specific structure of the square wave signals it's expecting (row order, pixel order, etc). This particular sign appears to use a 4mm pitch (space between each R/G/B led), indoor-level brightness SMD leds, and modules that are 32x64 pixels, like this one on AliExpress: https://www.aliexpress.us/item/2251832064290423.html?spm=a2g... ( ~$8 + ~$9 shipping to the US for single qty).

There are various "HUB75" panels of different pitch, brightness, LED type, matrix size, etc. Also, there's variations like "HUB75E" with 5 address lines instead of 4. Address lines are typically A/B/C, A/B/C/D, or A/B/C/D/E. And there's also "HUB08", "HUB12" and other standards.

Why would you buy retail if you are a company buolding and selling hardware to begin with?
Everything in the article screams that they did not know what they were doing.

Why would you think that a company using a $25 Adafruit HAT that could be found for a magnitude less elsewhere would be using cheap LED matrices?

Put another way, what from the article gives you enough confidence to say that they would have used cheaper parts?

I suspect the intention was to get an MVP out the door and get some initial "growth & engagement" so they can attract VCs - cost-effectiveness wasn't a priority at this stage.

It's a shame because there is a small but sustainable business here.

Have any signs in the field connected to your new API and updated?
Yes I reached out to another owner who was able to connect the sign to the API. I've reached out to more people but haven't gotten too many responses. It's been 5 years after all. If you know anyone with one of these signs send them this post!
I think the other mark on the back was for the reset button. Thanks for sharing.
Hello, author! That was interesting!
An interesting read. Thank you.
super interesting read, thank you for that.
Awesome work!