This $40 ESP32-S3 AMOLED map shows where you are without an internet connection

Credit: shubham030 Published Jul 29, 2026, 12:08 AM EDT Simon is a Computer Science BSc graduate who has been writing about technology since 2014, and using Windows machines since 3.1. After working for an indie game studio and acting as the family's go-to technician for all computer issues, he found his passion for writing and decided to use his skill set to write about all things tech. Since beginning his writing career, he has written for many different publications such as WorldStart, Listverse, and MakeTechEasier. However, after finding his home at MakeUseOf in February 2019, he would eventually move on to its sister site, XDA, to bring the latest and greatest in Windows, Linux, and DIY electronics. Sign in to your XDA account Summary This DIY bike GPS runs fully offline with pre-baked OSM tiles on microSD; no phone, WiFi, or internet needed. The demo used the $40 ESP32-S3 AMOLED with built-in GPS; the $30 board can work but may need external GPS data. The source code isn't released yet, but it will be released once it's cleaned up. Building your own navigation device is always great, but if you don't intend to travel too far, there's not much point in downloading the maps every time. Such is the case with this DIY bike GPS, which doesn't require any internet connection to let you know where you are. All the maps are local, and once you hook up GPS data to it, it'll let you know where you are even when there's no phone signal around. This $40 ESP32-S3 AMOLED map doesn't need internet to work It'll hopefully go open-source soon Over on the ESP32 subreddit, Shubham Gupta made a post describing their new project. They also included a YouTube video showing off the device, although the version they used in the video and in this project is the $40 GPS-enabled ESP32-S3 AMOLED, and not the $30 version the YouTube title mentions. Still, $10 isn't that huge a deal, and you can still get it working on the $30 one if you want, but you'll need some way to feed it location data. The coolest thing about this map is that it doesn't need to connect to the internet to work: The whole map runs on-device: no phone, no wifi, no internet. I pre-bake the basemap offline (OSM -> self-hosted tileserver -> 256x256 tiles), convert every tile to raw RGB565, and pack them into a fixed-grid file on a microSD. On the board there's no image decode and no per-tile index. Gupta notes that, right now, the moving dot + speed uses a hardcoded animation right now, as he's still working on wiring up the GPS part of his ESP32-S3 AMOLED. However, once he's done, it should look a lot tidier. The bad news is that Gupta hasn't released the source code yet. The good news is that he intends to release it eventually. In the comments on his Reddit thread, he says he'll make the code open-source "once it's less of a mess, still lots to do." If you're interested in making your own, be sure to keep your eyes on Gupta's channels for a release announcement. I know I'll have my eyes peeled.