Hi - I need to build a system that can track assets (containers) in large warehouses spread across a large site. I need to know where those containers are and the temperature. At a high level what would the hardware stack look like if I was to do this with the particle platform?
Believe it or not, GPS can be useful in some warehouse applications. This strictly depends on the structure and roof type, but it is viable is certain indoor situations.
In regards to Wireless Localization, I don’t know of any way to accomplish this with only Particle Hardware.
I’m working on a similar project, but it uses 900 mHZ Xbee radios for the RSSI info. The Anchors each send their RSSI info for all Rovers back to a Particle Gateway.
Wireless Localization may be possible with the next Gen Hardware to be released this Summer, but the range would be limited.
LoRa, or any other Sub-gHZ radios could be used.
Maybe an array of bluetooth beacons?
What does the process of relocating the containers look like?
If in the process the container can be “paired” to its new location (e.g. passing an NFC tag, bar/QR code patch, RF gate, …) you’d not need to monitor the location but only the transtion.
There are several WiFi based location services/libraries similar to the Google based one we already have access to. Many of these claim to deliver very high accuracy, but I haven’t encountered one with libraries designed for embedded hardware out of the box, so there is potential there but quite a lot of work possibly setting some parts of it up.
One example that caught my eye was this one https://anyplace.cs.ucy.ac.cy/ (but there really are many more) which includes mapping/layer tools to identify where you are on a site/in a building. I haven’t had the opportunity to look at it more closely but the impression I have is your need someone reasonably competent in the tools its put together with (the server bits and bobs) to set it all up wade through the documentation and create a webhook endpoint you can update via a particle device
have a look at the Pozyx system
@hl68fx, Thanks for that Post. I started looking at Pozyx after your post and it’s very interesting.
Have you used this equipment ?
The 2 downsides I saw in the Documentation are:
The maximum recommended Grid size for Anchors is 28m x 28m
The tags can contain an anchor-list of up to 15 anchors, maximum.
Do you know of any workarounds for Large Sites ?
You might want to check this out: https://www.accuware.com/products/locate-wifi-devices/
They only show high-level functionality on their site so you would probably have to talk to their sales staff.
This topic has me thinking… I’m an IT manager and computer networking is a focus of mine. If you have a grid of evenly spaced wi-fi access points in your space, is it possible to measure the signal strength of each AP using a particle device? I know the photon can scan for SSIDs and report their strength. Perhaps doing the spacial calculations might be easier to process on a full-blown computer/server… and so if a container has a Photon in it scanning for APs, it could report the top 4 or 5 APs back to a central PC that would do the triangulation to figure out coordinates. You would need at least 3 APs in sight of the particle device to get a 2D position.
How accurate are you trying to go? If you use directional AP antennas, then you could figure out which AP the photon connects to which would get you within whatever square footage the antenna covers. Then no calculation is needed. In large venues with high-density device counts, they typically have overhead, directional antennas that point straight down. Each antenna is responsible for a small portion of the venue. Think of it like a spot light shining down on the floor; it creates a cone. As long as you are in the cone of the AP signal, you will know where the object is. Depends on your ceiling height… Taller the ceiling, the less accurate it will be. And this wont report vertical position, simply horizontal position.
I think WiFi without special hardware is notoriously inaccurate for this type of ranging. Both the access point and the clients will boost power and reduce the modulation scheme to create an effective link, so unless you can access and control the WiFi radio at the very lowest levels, it is really very difficult to use RSSI for ranging with WiFi. It can work, but not generally on standard hardware.
Thanks for the thoughts so far.
This chip was suggested to me today - https://www.decawave.com/products/dw1000
It seems to be the one used in the Pozyx system suggested above.
The Decawave is also where I ended up after spending most of the day reading.
A kit of 12 devices comes to $25/each, at Digikey.
From their Forum, Rev 2 of the firmware should make major improvements for a Large Site.