August 4, 2026

It’s not an easy job to make a small enclosure for small components. Wires take too much space. I bought smaller LiPo batteries and see if they fit better, or if I can rearrange them in a way that makes the enclosure thinner. Probably won’t work. The 3D prints are not as sexy as I imagine, but for a prototype is okay.

July 17, 2026

A month has passed and I’m finally getting back to this project. I tried designing a custom PCB on my own, because I thought it would be a cool project to fail and learn – and I failed miserably and had to take care of other things. Following the last update, I finally included a custom prompt to each click. Even if I carefully select categories, I can refine the GPT-5 filtering with prompts. Google Places API gives it enough data to work on. The next step is figuring out a device enclosure. This time, no custom PCB - too expensive for hobby projects, specially if I need to iterate faster. I’ll try using a perf-board this time.

June 12, 2026

Made some improvements on the iOS prototype. I’m digging into what’s possible on the app side after going for a walk with the device. It’s kinda addictive at first: just a click of button and I have recommendations ready to discover. I noticed that a few steps further, sometimes the recommendations would change completely. Then I thought about adding some more capabilities, like being able to toggle on and off some options and the clicks are responsible for. I added GPT-5 acting on the background as well. It takes the raw data from Google Places API and filter out locations with bad reviews and some other things. For my case, I hardcoded the prompt to exclude fast-food chains. In a list with 10 restaurants, 8 were fast-food chains with top reviews. But I am not interested in fast-food that much.

June 6, 2026

With XIAO connected and some initial setup done, I could finally build an iOS app prototype. This looks like something that came straight from 2006. The way it works is actually pretty simple for now: when I click on the button, XIAO sends a bluetooth signal to the phone, the app captures it and search for locations (predefined categories) based on my phone GPS. My phone has to be connected to the internet right now, otherwise it won’t work. When putting pieces together, the battery was the hardest part. XIAO is really small and the solder pads are even smaller. Had to solder it on naked eye, no magnifying glass available. Feel very good to have a walkable device, paired to my phone, doing things I want. My initial concept for how they both communicate was: one click for "love it" and double-click for "want to go", that later became one click for food and restaurants and double-click for cultural and arts.

June 5, 2026

XIAOs arrived. So impressive how tiny they are!

June 3, 2026

Starting a very simple concept: I want to carry the device around, like on a keychain. Should be so small that it fits my jacket’s pocket. The definition of the size is the right thing to do at the beginning, because that’s what determines the components I’m gonna use. That also helped Claude tell me what to buy: so the initial list was a XIAO nRF52840 a 3.7V LiPo battery and a tactile button, nothing else.

June 2, 2026

My Google Maps is filled with want-to-go saved locations. Sometimes it’s just a neighborhood I found interesting and wanted to bookmark to browse it later, see what things I can do there, apartments to rent, restaurants, cafes and cultural leisures. While driving or on a Uber, you gotta be fast, otherwise you lose track of your location. I usually memorize the easiest store front sign and search it seconds later. Sometimes I can save the exact location, but most of the times I miss the exact location. When walking around the steps are always: grab phone → open the map → wait for geolocation → zoom-in and find the location → bookmark want-to-go or favorite. Very usual, everyone does that. But this process could be faster by simply tapping the button and collecting places I wanna see and visit. I will look at my phone later anyway. So, I sketched the idea: a "location pin". This is the sketch I handed over to Claude and the journey begins.