This post is not primarily about Pascal, but hopefully will inspire some to combine Pascal, microcontrollers and a bit of DIY.
There are spots around my house that is not properly covered by my single wifi router (TP-Link TL-MR3420 v2 running OpenWrt). I thought it would be interesting to build a
cantenna on the cheap to see how much one can improve wifi (2.4 GHz) signal. Doing it cheaply was my main motivation, so instead of the recommended 50 Ohm cable and SMA connectors, I settled for an RG6 TV cable with F-connectors. The coaxial cable was connected to an ESP32-WROVER-IB board with a U.fl connector (connector stripped form an old DSL router) soldered to the end of the RG6 coaxial cable. So pretty much not how it is supposed to be done... Attached a picture of the cantenna mounted (with sticky tape) to a tripod.
To record the wifi signal strength I wrote a simple
Pascal program that connects to the router and send the RSSI value over serial every second.
For reference other boards with build-in antennas were also tested, see attachment
Wifi signal tests.png. In this test the cantenna signal was on average 8 dB stronger than the best board. Surprisingly the humble
ESP-01 came second out of the boards with onboard PCB antennas. Another interesting observation is that the bottom three boards all have their modules with PCB antenna mounted on top of another PCB that covers the bottom side of the antennas.
In general the best orientation for signal strength is when the copper tracing of the PCB antenna is facing the router.