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Comment by Goz3rr | Hacker News Reader

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.

Why would you buy retail if you are a company buolding and selling hardware to begin with?

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.

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?

"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.

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