Hey! I'm part of a nonprofit working to make educational content more accessible to the developing world.
The strategy is to load educational content onto a device that can act as a router, so children nearby can access the content through a smartphone (even if they don't have WiFi). This has been implemented here (https://worldpossible.org/). However, these devices are pretty expensive and are for large-scale use.
A product called ZoomGo is $5-$10 and is used for wireless in-car entertainment. ZoomGo has been previously discussed on this forum. We were planning on loading educational content into ZoomGo and having it function as a router. Unfortunately, we could not get the phone app to open and the reviews for the app are very bad.
I'm wondering if there's a product at a similar price point to ZoomGo that we could use? I'm not very technically-savvy, so I wanted to post here to ask. Any suggestions are welcome!
Thanks for the suggestions. I'll look into this more.
Most people in developing countries have a smartphone, but they have a limited amount of cellular data. Also, there usually isn't WiFi. Thus, we're hoping that a smartphone can be used to interface with the AP.
Thanks! Yes, it will likely be text/html files (no video for now).
I'm wondering if you might know how many users a Rasberry Pi Zero can serve and which geographical radius they need to be in? For instance, would it be able to handle requests from 20 kids in a classroom or 50 kids within a 10 mile radius?
Sorry for all the questions! I'm very much a beginner.
No regular wifi device is capable of covering a 10 mile radius.
Try 50+ meters, if you have a clear line of sight.
Even if you had a router/AP/whatever capable of covering a 10 mile radius, the clients (cell phones) would have to be capable of doing the same, to be able to communicate with the host device, which they aren't.
The truth regarding range lies in the middle. With line of site and consumer grade 2.4GHz hardware it is possible to create links even of a few kilometers if you are out of the urban zone and it's thousands of radio transmitters make a lot of noise.
For example, I managed to use 2x TL-WA801 to create a link with several MBit/s speed over about 2km distance in a desert/mountain environment (over a valley).
That being said, if the other end is a smartphone or tablet which usually has only ~40mW transmit power, don't expect more than a few hundred meters even under perfect conditions.
You find used/refurbished 802.11bgn gear around the same pricetag (US$10). With the wifi chip of the PiZero you will not be able to serve more than a handful of clients (and that's optimistic) and you have to significantly lower your expectations regarding range...
I was more thinking about used/refurbished ready-made routers, ie. including a case, antennas and a power supply.
It's true that the processing power and RAM of those look ridiculous when you compare to the Pi Zero -- but for this application you need neither a lot of RAM nor processing power (a single 300Mhz core and as little as 32 MiB of RAM and 8 MiB of flash are enough to serve files from a pendrive via HTTP; sure, a bit more of RAM comes handy as filesystem cache and reduce re-reading from USB...).
It's quite easy. you need a few software packages installed (ie. usb storage driver, filesystem support, blockd for automouting) for being able to mount the external disk. A http server is already included in OpenWrt (uhttpd) and it can be configured to serve the files on the pendrive.
The bottleneck here is bandwidth which limits the bitrate of the video files you can serve in real-time. If you are not insisting in Full-HD or 4k content but 480p or 360p is fine, streaming even to multiple simultaneous clients will work well. Most important: Using a RasbPi will not make it better as the Wifi chip is worse than any router out there.
To get started, I'd go with GL.iNet GL-AR150. There are slightly cheaper devices than that, but less than 64MiB of RAM or super-old WiFi chips don't make it better...
Thank you so much!
For setup, would this tutorial suffice?
I'm also wondering if you think wireless SD cards like Zsun Wifi Card Reader would work for us? It's around $10 as well, and would be slightly cheaper overall since we wouldn't need to buy a USB stick. I'm not sure if the WiFi capabilities are good enough to justify the cost savings, though.