Sensorgnome WiFi

Scripts and config to enable/disable WiFi client and WiFi hot-spot. The scripts/code in this directory provide a customized experience around configuring and enabling WiFi. In the end, they configure and enable/disable features using the standard tools. On rPi this means:

• WiFi client set-up using cli
• routed hot-spot set-up (this is not the exact set-up used)

The Sensorgnome WiFi client is configured using a network.txt config file. This file is typically placed in the fat32 /data partition so it can be edited on a windows laptop. The WiFi client is enabled at boot if config is provided, after that the std wpa_supplicant daemon manages it.

The Sensorgnome hot-spot is enabled via a hardware button that is polled using the gestures.js and pushbutton.js scripts. The hot-spot configuration is fixed and uses the Sensorgnome's ID. The button and associated LED pins can be configured in gestures.txt to a limited degree.

Notes:

• The WiFi client and the hot-spot are almost completely independent and can operate simultaneously, enabling/disabling one has almost no effect on the other (it appears that when the hot-spot is disabled then the client connection briefly drops as well before it gets re-established).
• If the network.txt is configured on a running system typically a reboot is necessary for the changes to take effect, it may be possible for them to take effect immediately if one runs sudo systemctl restart WiFi-init.
• If WiFi client and hot-spot are enabled at the same time, then the channel used depends on the client side (i.e. the access point being connected to). Beware that this may be a 5Ghz channel and thus the hot-spot may also be on 5Ghz.
• If the WiFi hot-spot is enabled without WiFi client connection the channel used is No.1
• The hotspot operates as captive portal, see the ../web-portal directory

Dev notes

(See also top-level README.)

The hotspot starts dnsmasq to respond to DNS queries from clients, which is a required feature, and it responds with 192.168.7.2 to every query (captive portal). By default resolvconf picks up on the fact that dnsmasq is running and sets /etc/resolv.conf to point to it, which breaks all DNS resolutions. This package adds "deny_interfaces=lo.dnsmasq" to /etc/resolvconf.conf to prevent that.

The sg-WiFi-button.deb package can be installed and tested on a vanilla rPi provided the following are present:

• /etc/sensorgnome directory must exist (sudo mkdir -p /etc/sensorgnome)
• /etc/sensorgnome/id is initialized (ex: echo 1234RPI45678 | sudo tee /etc/sensorgnome/id)
• a reboot is necessary after the first install before testing to get the device tree overlay loaded

About all the files here... There are four groupings:

• etc-* files are config snippets for standard daemons that find their way into /etc/...
• gestures* are files related to the daemon that polls the button and blinks the LED
• gpio* are files to init the GPIO pins used by the gestures daemon
• WiFi* are files that handle WiFi client and hot-spot configuration