[escobar]

There's not much actual information available (this should be concerning), but there have been some clues dropped into past HN threads. This is a picture posted in another HN thread of their "original sensor" which is just 2 basic IR sensors: https://s3.amazonaws.com/screenshots.angel.co/73/340163/7982...

As far as I can tell from the updated website, the new sensor is the same thing, just dressed up nicer. Each sensor is only counting one metric, i.e. ingress. Beyond that, the base hardware (not the sensor) is a Raspberry Pi that connects to both the sensor(s) and WiFi. I'd imagine it would make sense to have many sensors for each box, but maybe not.

[pkelchte]

Hi, that's indeed our old sensor which is composed of two AIR sensors. The new sensor carries a slight upgrade in hardware, but the real power comes from our signal processing. See my reply to thwest here. https://news.ycombinator.com/item?id=9879671

[escobar]

So you use 2 different IR sensors, which "measure your circumference to some degree" and provide a "distance profile" which somehow translates into real-time accurate foot traffic counts. IMO that's definitely a cop-out explanation, and per usual, there is not any actual quantification.

[nemik]

Hmm, look's like Vishay's VCNL3020 in there? Or the good ol' Sharp GP2Y0A21YK0F.

Left wondering why you need a base controller and the dual-PIR's though, especially if the PIR's are connected to DC voltage anyway and not battery-powered like some other commentor said.

I get you would wanna use wifi to talk up to your cloud and maybe that's what the base is for. But seems like a waste if you got something expensive like a Raspberry Pi or other ARM A-series in there. There are much cheaper wifi chipsets out there now these days that could do the same thing without needing all that cost and space of an ARM Cortex A-core, plus wifi, Linux, etc. You could probably get away with putting a small wifi chipset in each of the dual-PIR housings and still come out ahead in cost. The ESP8266 sounds perfect for it actually.

Either way, a pretty cool product.

[HeyLaughingBoy]

Using an Rpi gets you to market much, much faster. Then optimize for cost after it gets popular.

[Smushman]

Andrew @ density.io answered this for me.

It can determine traffic direction; which is a leap beyond current technology i.e. a break beam, which cannot.

[serf]

> It can determine traffic direction; which is a leap beyond current technology i.e. a break beam, which cannot.

all it would take is two or more beams and some pretty simple code, am I missing something?

[escobar]

Nope, not missing anything. There are 2 beams (IR) per one of their "sensors", and it's assumed they're determining direction by noting which beam fires first vs second.