Air Canada’s Chatbot: Why RAG Is Better Than An LLM For Facts

Recently Air Canada was in the news regarding the outcome of Moffatt v. Air Canada, in which Air Canada was forced to pay restitution to Mr. Moffatt after the latter had been disadvantaged by advice given by a chatbot on the Air Canada website regarding the latter’s bereavement fare policy. When Mr. Moffatt inquired whether he could apply for the bereavement fare after returning from the flight, the chatbot said that this was the case, even though the link which it provided to the official bereavement policy page said otherwise.

This latter aspect of the case is by far the most interesting aspect of this case, as it raises many questions about the technical details of this chatbot which Air Canada had deployed on its website. Since the basic idea behind such a chatbot is that it uses a curated source of (company) documentation and policies, the assumption made by many is that this particular chatbot instead used an LLM with more generic information in it, possibly sourced from many other public-facing policy pages.

Whatever the case may be, chatbots are increasingly used by companies, but instead of pure LLMs they use what is called RAG: retrieval augmented generation. This bypasses the language model and instead fetches factual information from a vetted source of documentation.

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A breadboard showing a tiny ESP32 board and two HMC5883L sensors connected to it on different pins

Avoid I2C Address Conflicts On ESP32 By Pin Muxing

Using hardware I2C on an ESP32? Do you need to connect multiple I2C devices with the same address? Normally, you wouldn’t be able to do that without extra parts, but on the ESP32, [BastelBaus] has found a nice hack — just connect your devices to different pins and slightly abuse the ESP32 GPIO muxing, no extra hardware required!

Initially, they tried separating SDA and SCL completely, and after a bit of tinkering, that’s worked out wonders! For this method, [BastelBaus] provides example Arduino code you could easily integrate into your project, and shows logic analyzer captures that demonstrate there’s barely any overhead. Later, they’ve also found out that you could multiplex only one of the pins, specifically, SDA, having the SCL line be common! As far as we see, this could also work out with split SCL, but do let us know if that doesn’t sound right.

Typically, such a problem is solved with an I2C multiplexer, and we’ve highlighted projects with them before. However, this simple method could also work on chips like the RP2040 or even the Raspberry Pi 4 — just a bit more limited, since the GPIO muxing for I2C has less available ports! Also, if you’re not using a chip with such a comfortable GPIO mux and you must use devices with overlapping addresses, check out the comment section under our I2C ecosystem article – there’s a fair few other methods you can use. And, if this method ever malfunctions for you, there’s a bunch of very straightforward ways you could debug your bus!

ESP32 Weather Station Looks Great With Color E-Paper Display

[] has built weather stations before, but his latest is his best yet. It’s all thanks to its low-power design, enabled by its e-paper display.

The build is based around an ESP32 microcontroller, combined with a BMP180 sensor for measuring barometric pressure, and a DHT22 sensor for measuring temperature and humidity. By taking these values and feeding them into the Zambretti algorithm, it’s possible to generate a rudimentary weather forecast.

The weather station looks particularly impressive thanks to its six-color e-paper display. It’s brightly colored and easy to read, and displays graphs of temperature, pressure, and humidity over time. Plus, by virtue of the fact that it only draws power when updating, it allows the project to last a long time running solely on battery power.

As far as DIY weather stations go, this is an attractive and clean design that offers plenty of useful data to the user. We’ve seen some other neat builds in this vein before, too.

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