I took a $30, beat-up Android phone with a shattered screen and tried to turn it into a tiny home server that could run Home Assistant 24/7. On paper, it sounds perfect: phones sip power, they’re dead silent, and they’re already sitting in a junk drawer. In reality, it was absolutely not plug-and-play. I went down the PostmarketOS route because I wanted a “real” Linux distro (with a kernel and everything) instead of trying to fight Android + Termux + rooting just to get Docker behaving. I walked through the messy process of flashing PostmarketOS, getting SSH working, and then battling Docker networking issues that ultimately came down to nftables. I got Home Assistant running great, but only after adding the right firewall rules (including mDNS and a very “accept unsolicited UDP” kind of rule so discovery would actually work). Then I tackled the bigger long-term problem: power. I didn’t want a spicy pillow situation from running a battery forever, so I removed the battery and used a janky-but-effective diode drop to feed the phone a safer voltage. In the end, I got a compact, wired, headless Home Assistant box that idles at about 1 watt and only pulls around 6 watts under stress. It was a pain in the butt—especially the nftables part—but it was also genuinely fun, and a surprisingly useful way to repurpose old hardware.