Lawnmower's immobilizer prevents using the lawmower. Disable the PIN code and claim the device. This job requires some specific skills - use Bus Pirate as SPI bus master to access the Flash chip on the device. First dump the existing firmware as-is. Enter the PIN incorrectly again and attempt to identify which part of the Flash counts the invaid PIN code attempts. Try to reset the counter first.
Using wide angle IR equipped USB webcams and OpenWrt capable boxes set up video surveillance system covering the whole hackerspace. Aggregate video feeds on a server and using Python scripting create motion detection software which notifies about activites on a Slack channel. Using the wireless access points sniff MAC addresses of the devices present and map recognized MAC-s to hackerspace members. Pass events through simple event correlator and send alert if
Deploy LEDE in dummy access point mode on TP-Link Archer C7 devices and cover the hackerspace with 802.11ac wireless network. Set up guest network with VLAN 143. This project requires decent managed swich capable of VLAN tagging. If you're asking why TP-Links and LEDE then the answer is quite simple - those boxes have USB ports so we can hook up USB cameras for video surveillance. There are some PoE splitters so we can power the boxes from PoE switches as well.