electrical/

Assembly Notes

Required Hardware Modifications

The following hardware modifications are required before/during assembling each reader unit.

• Remove LoRa IC (SX1278) from ESP32 TTGO dev board:
  1. Remove OLED screen screws.
  2. Use hot air / reflow tool to remove the SX1278 IC from the board and clean the traces.
  3. Replace the OLED screen screws.
• Disable pin 12 for Y-axis input GPIO, use pin 14 instead:
  1. When soldering the male header pins to the ESP32 TTGO dev board, cut/remove the header pin for pin 12.
  2. Make a solder bridge on the bottom of the PCB, shorting pin 12 and pin 14..
• Disable automatic card read beep on new RFID readers:
  1. Obtain the HID Global configuration card from the ACM parts kit.
  2. Power off the new RFID reader unit.
  3. Place the configuration card within scanning range of the reader (still off).
  4. Apply power to the system while holding the card in position, and wait for the RFID reader to begin flashing red/purple (may require several seconds).

Wiring and Machine Connections

4-pin X/Y Motor Connector

The 4-pin X/Y motor connector is connected to the Pulse diode pins on the X/Y motor controllers. The measurement is isolated and should be able to measure a wide range of signals with the current voltage divider values for R3 (680), R4 (680), R5 (470), R6 (470).

3-pin IoT Relay Connector

The 3-pin IoT relay connector has inverted logic which expects the safety equipment to be plugged into the "Normally Closed" side of the IoT relay power bar. In this configuration, a power fault or other error should activate the safety equipment until the fault can be restored.

2-pin Interlock Connector

The 2-pin Interlock connector should be connected in series with the interlock circuit of the machine. The output is connected OPEN / CLOSED via a solid-state relay (SSR) on the PCB.

Power-On Behaviour

The initial state of the IoT relay at boot (or after error recovery) is ON. This is a safety-first guess, and the correct state of the relay will be set after the first tag is scanned.

Schematic

makerlabs-acm-reader-lock-v1.0.1 - Schematic

PCB

Top Layer

makerlabs-acm-reader-lock-v1.0.1 - Top PCB Layer

Bottom Layer

makerlabs-acm-reader-lock-v1.0.1 - Bottom PCB Layer

Bill of Materials (BOM)

Generating from KiCad / KiBOM

The KiBOM KiCad (Python) plugin is used from within the KiCad schematic editor to generate a BOM file in CSV format. The values are stored in the schematic part libraries for each part.

Note

The special fields used within each part (e.g. MFN/MFP, S1PN/S1PL) come from the following KiCad BOM article: https://rheingoldheavy.com/kicad-bom-management-part-1-detailed-components/

To (re)generate the BOM CSV file:

1. Clone the KiBOM Python plugin:

   git clone https://github.com/SchrodingersGat/KiBoM

2. Open the KiCad schematic editor, and the target schematic.
3. Click the BOM icon near the top-right
   • If KiBOM_CLI is not yet in the Plugins: list
     1. Click Add Plugin
     2. Navigate to the KiBOM_CLI.py from the git repo cloned in step 1.
     3. Ensure the Command line: setting is similar to the following, noting that the output file should end in _BOM.csv

        python "<full/path/to/KiBoM>/KiBOM_CLI.py" "%I" "%O_BOM.csv"

4. Click the "Generate" button to generate a new CSV file.

BOM CSV

makerlabs-acm-reader-lock-v1.0.0 - BOM

API Reference

electrical/ KiCad Project Files Overview