In conjunction with MakerSpaceAPI you can create rental items. These items like power tools, etc. need UHF Tags in/on them. The easiest way to place them properly with no to little wear is within the tools case. This standalone ESP32 with an Fonkan UHF Reader (FM-505, bigger antenna = better) is then used to trigger alarms on unrented items leaving the space. You can either connect it to Home Assistant via MQTT and/or use it with an external alarm output.
The catalog from the MakerSpaceAPI is updated on a regular basis (should be fast enough to not trigger on just rented items). If a Tag is detected, the ESP checks, if the item is rented, if true, nothing will happen. If the item was not rented, the alarm output will trigger as well as a binary sensor in Home Assistant. You could attach a mosfet with a 12V siren to it or trigger anything else with it. Tags will trigger repeatedly in a configurable timeframe (every 10s by default).
You can control the reader and see tags/names in Home Assistant via MQTT. The following sensors are exposed:
- Tag ID (will also update on tags not in the catalog)
- Item Name
- Unrented Item Name
- Unrented Alarm (will stay on for 1s after a scan)
Adjustable settings:
- Region of the UHF reader
- Power in dBm
- Scanning on/off
- Scanning on/off on boot
We've had some issues with a Danalock Z-Wave lock, which got jammed by the UHF Reader. So these settings allow for finetuning the detection range as well as disabling scanning, e.g. when you want to send a Z-Wave command. The modules will be preprogrammed by Fonkan to the region you ordered, but checking is always better.
This is a basic implementation of a warning system. Trust is always key in a maker space, but sometimes you simply search for a tool that another person just lend out. This system should make it easier for all to remember notifying others by renting the things. Currently rented items are only shown to the renting user, to the admins and is exposed to Home Assistant via the MakerSpaceAPI-HA Integration. This is no proper antitheft solution. The system currently relies on the EPC memory of the tags. This memory can be reprogrammed, if you are worried about this, make sure to password protect the tags before installing them. Be nice and label the things with the names from the system, especially if you got more of the same kind (like jigsaw#1), so users can quickly check the list online.