Machine Access Node
Hackspace has machines, that ideally need to be inducted and access controls for safety reasons. A vital step towards the goal of 24/7 access on membership. A bonus of the system would be usage tracking and maintenance notifications.
A solution is a control device consisting of a box which enables the machine for as long as your RFID card is in the box. A Tool Access Node.
Potential design
- Esp8266
- 3A Relay
- bi colour LED
- Card interface header
- DPI switch addressable (or other)
Functional Specs
Mission Critical
These must work without networking or the main server being avalable.
- Check if card valid in local storage
- Set tool into "out of order" mode - must work without networking
Functions
- Relay contacts of at least 10 amps for switching the device. Hard-wired in using suitable grommets and with sufficient isolation between low and high voltage.
- Internal database of (up to at least 200*) authorised RFID card IDs, plus a flexible way of fetching updates from a membership server.
- Logging of who used the machine + hours used.
- Open Source hardware & software.
- Status light, for "active", "denied" and "thinking". (Although "active" is really the only important one, and blinking is fine)
- Fits in a standard backbox.
"Nice-to-haves"
- Ideally sub-£30.
- Mains Powered
- Ability for super-users to program new cards from the device - this should result in a callback to a membership server to verify it.
- Easy to program/modify
- Ability to monitor "actual" hours run - i.e. how long the laser cutter tube is actually on for. (This could potentially be done using a current transformer sensor.)
- Ability to poll for current state over the network.
- Broadcast events on the network.
- Ability to update the software over the network.
- Relay / Darlington / Servo output configurations.