The Hacklab door controllers are based on an ESP8266 wifi microcontroller and a PN532 NFC reader module. One controller is installed for each door, and each controller can operate a single 12V channel for an electric door release or magnetic lock. Inputs can be connected for door open/closed reed switch, exit request and local lock/unlock “snib” function.
|C1||1206 10uF 25V||2320887|
|C2||1206 22uF 6.3V||2320911|
|C3, C4||0603 0.1uF 6.3V||1759016|
|D1||SMA diode B230A||1843686|
|D2||SMA diode (flyback protection)||1625280|
|JP1||PCB male header 2.54mm pitch 3-way|
|JP2||PCB male header 2.54mm pitch 2-way|
|L1||Coilcraft LPS6225-472MRB 4.7uH 2A||2408256|
|P1, P2, P3||PCB screw terminals 5.08mm pitch 2-way (9 total)|
|P4||PCB male header 2.54mm pitch 6-way|
|Q1, Q2||MOSFET-N SOT-23||2069541|
|R1||0603 31K6 1%||2059454|
|R3||0603 56K 1%||2303215|
|R2, R4||0603 10K2 1%||2059407|
|R5, R6, R7, R9, R10, R11||0603 10K 1%||2303192|
|R8||0603 2K2 1%||2303166|
|SW1||EVQPT5 tactile switch||2425617|
|U2||SRD 12V relay|
Errata: a generic through-hole flyback diode should be fitted between GND and 12V_OUT, on the underside of the screw terminal.
Future PCB revisions are likely to be based on a Wemos D1 Mini module to reduce component count and allow easier debugging. The onboard DC-DC converter will be replaced with an off-the-shelf “LDO replacement” DC-DC converter module.
The laser-cut mounting plate is designed to hold the PCB secure at the back of the enclosure. Attach the PCB with M3 nylon bolts and nylon or metal nuts (the nut should go above the board to minimise the space used below the mounting plate).
The mounting plate should secure itself reasonably well with a push-fit, but consider adding a rubber foot or a blob of hot-melt glue to prevent it from rocking.
Drill a large hole in the side of the enclosure for wiring. Drill screw holes for wall-mounting. Drill two holes in the enclosure lid for the LED and push-button.
The push-button and LED may be wired as two separate pairs, or with a shared GND. The LED should have a 120R series resistor.
Connect the reader cable to the 8-way screw terminals. The controller push-button should be connected to the GND/SNIB pair of terminals. The controller LED should be connected to GND and LED (shared with the reader).
Take care to keep wiring away from the antenna.
Circuit diagram: PDF
The reader enclosure is formed from three layers of 3mm black acrylic. The layers should be joined with cyanoacrylate adhesive.
Configure the PN532 module to use I2C communications.
Bend and cut the LED leads to the correct shape and length. Solder the LED and cable before gluing the module into the enclosure.
Cable colours in Hacklab installations:
|Pin||G1/G2/G8||G11 (and photos)|
The LED should be connected between LED and GND, with a 120R series resistor. To avoid damaging the LED, use hot-melt glue to secure it in place (not cyanoacrylate).
The piezo should be connected between PIEZO and VCC (green). The piezo may be secured with cyanoacrylate or hot-melt glue, but try to give the disc some freedom of movement or the sound output may be reduced.
Test the reader and controller together before securing the reader to the wall with double-sided adhesive foam tape.
Two versions of firmware and server back-end are currently in operation.
Legacy/Stable: The older version uses UDP networking and requires a dedicated wifi network for security. All of the Hacklab doors use this version at the time of writing.
New: A new firmware and back-end use TLS-enabled TCP networking, so do not require a special wifi network. The modern codebase is better-written, more flexible and features OTA upgrades.