Introduction: IOT123 - ASSIMILATE SENSOR HUB: ICOS10 GENERIC SHELL (IDC) ASSEMBLY

By bend. break, blend
About: The tension between novelty and familiarity...

NOTE

This is an improved (circuit robustness) version of the ASSIMILATE SENSOR HUB: ICOS10 GENERIC SHELL (HOOKUP WIRE) Assembly. It assembles quicker and has a higher quality circuit, but costs more (~$10 extra if supporting 10 sensors). The main feature is it is very modular now: panels and cables can the replaced/customized without the need for de-soldering/soldering.

SUMMARY

Slated are several ASSIMILATE SENSORHUBS. They have a common metadata and sensor dump interface with I2C ASSIMILATE SENSORS. That means a new sensor can be developed, and the MCU that hosts it does not need to be reprogrammed to accommodate the new functionality - just plug it in and reboot. The sensor data will be automatically published to a MQTT server. We expect to develop ASSIMILATE ACTORS support: post a MQTT topic that the HUB listens to, and then routes the message to an actor (relay, indicator etc).

One range of the ASSIMILATE SENSOR HUBS is the ICOS10: a geometry based on the upper 3/4 of the Platonic Solid "Icosohedron", which can host 10 sensors. This separates the individual sensors which can affect one another's readings and provides room for larger compound mashups.

The range is expected to support different MCUs and power arrangements, so the reusable tasks have been split up into separate instructions. The main hardware functions of the HUBs are developed as inch square daughter boards that can be swapped out for enhanced/different functionality.

This article concentrates on the assembly of the outer shell of the housing that has 10 sockets for sensors and a panel for accessing power for the unit. This shell may be useful for other IOT projects.

Step 1: Materials and Tools

Bill of Materials and Sourcing list.

  1. 3D printed parts (1 set)
  2. 3D printed Header Jig (1)
  3. 3D printed Void Punch (2)
  4. 3D printed Collar Jig (1)
  5. 3D printed IDC Header Solder Jig (1)
  6. 3P Female Headers (20)
  7. Ø 0.8mm wire (~1m)
  8. 6 Wire Ribbon Cable (~1m)
  9. 6 Pin Shrouded IDC Male Header (11)
  10. IDC-6 Socket 2×3 Pins Connector (11)
  11. Wire Cutters (1)
  12. Small Pliers (1)
  13. Solder Flux Pen (1)
  14. Solder and Iron (1)
  15. Hot Glue and Gun (1)
  16. Strong Cyanoachrylate Adhesive (1)
  17. 4G x 6mm self tapping countersunk screws (~20)

Step 2: Preparing the Panels

The socket panels (TYPE 1) can be prepared before the joining of the panels. The JIGs used may need filing to fit initially; they were designed with tight tolerances (based on my printer).

INSTALL SOCKETS

  1. Add 2 of 3P Headers and 1 off Key into the HEADER JIG.
  2. Use VOID PUNCH on TYPE 1 PANEL if needed to clean up edges of voids.
  3. Add flat side of TYPE 1 PANEL to assembled HEADER JIG, keeping tops of HEADERS/KEY aligned with bottom of HEADER JIG.
  4. Cover pins with reusable cardboard mask to stop glue hitting pins.
  5. Use Cyanoachrylate in thin layer on edges where HEADERS/KEY touch the PANEL. Allow to dry.
  6. Tin PCB pins on IDC Header.
  7. Insert IDC Header onto IDC SOLDER JIG.
  8. Insert Tinned 0.5mm wire into JIG holes.
  9. Solder wires to pins and leave 10mm wire hanging out of JIG (center holes can be cut flush).
  10. Remove IDC Header and wires from JIG.
  11. Bend wires at right angles as shown in diagram.
  12. Insert IDC Header and wires onto guides onto TYPE 1 PANEL.
  13. Bend wires as shown in diagram and solder. Trim excess.
  14. Test wiring for continuity if needed.
  15. Fill walls around VOIDS/HEADERS with hot glue. Allow to cool.
  16. Carefully remove HEADER JIG.

AFFIX COLLAR

  1. Add a collar inverted to the COLLAR JIG, lining up the notch.
  2. Add the assembled TYPE 1 PANEL, flat face down on the COLLAR, forcing contact between the two.
  3. Ensure holes line up, and COLLAR holes are clean.
  4. Add a dob of hot glue to each hole; it will seep into the lower one without force.
  5. Allow to cool.
  6. Pry PANEL/COLLAR carefully from JIG.

Step 3: Joining the Panels

When the wires are inserted, they can be cut off flush with outer hinges afterwards.

  1. Take 2 PANEL TYPE 1's, align Side (2) holes on PANEL (1) with Side (1) holes on PANEL (2) and insert wire using pliers/cutters.
  2. Align Side (2) holes on PANEL (2) with Side (1) holes on a new PANEL TYPE 1 "PANEL (3)", and insert wire using pliers/cutters.
  3. Align Side (2) holes on PANEL (3) with Side (1) holes on a new PANEL TYPE 1 "PANEL (4)", and insert wire using pliers/cutters.
  4. Align Side (2) holes on PANEL (4) with Side (1) holes on a new PANEL TYPE 1 "PANEL (5)", and insert wire using pliers/cutters.
  5. Align Side (2) holes on PANEL (5) with Side (1) holes on PANEL (1), and insert wire using pliers/cutters.
  6. Align Side (3) holes on PANEL (1) with Side (1) holes on a new PANEL TYPE 1 "PANEL (6)", and insert wire using pliers/cutters.
  7. Align Side (3) holes on PANEL (2) with Side (1) holes on a new PANEL TYPE 1 "PANEL (7)", and insert wire using pliers/cutters.
  8. Align Side (3) holes on PANEL (3) with Side (1) holes on a new PANEL TYPE 1 "PANEL (8)", and insert wire using pliers/cutters.
  9. Align Side (3) holes on PANEL (4) with Side (1) holes on a new PANEL TYPE 1 "PANEL (9)", and insert wire using pliers/cutters.
  10. Align Side (3) holes on PANEL (5) with Side (1) holes on a new PANEL TYPE 1 "PANEL (10)", and insert wire using pliers/cutters.

    The order of the remaining panels is not important, basically connecting the 2 sides of the later panels...
  11. Align Side (3) holes on PANEL (10) with Side (1) holes on a new PANEL TYPE 2 "PANEL (11)", and insert wire using pliers/cutters.
  12. Align Side (2) holes on PANEL (11) with Side (2) holes on PANEL (6), and insert wire using pliers/cutters.
  13. Align Side (3) holes on PANEL (6) with Side (1) holes on a new PANEL TYPE 2 "PANEL (12)", and insert wire using pliers/cutters.
  14. Align Side (2) holes on PANEL (12) with Side (2) holes on PANEL PANEL (7), and insert wire using pliers/cutters.
  15. Align Side (3) holes on PANEL (7) with Side (1) holes on a new PANEL TYPE 2 "PANEL (13)", and insert wire using pliers/cutters.
  16. Align Side (2) holes on PANEL (13) with Side (2) holes on PANEL PANEL (8), and insert wire using pliers/cutters.
  17. Align Side (3) holes on PANEL (8) with Side (1) holes on a new PANEL TYPE 2 "PANEL (14)", and insert wire using pliers/cutters.
  18. Align Side (2) holes on PANEL (14) with Side (2) holes on PANEL PANEL (9), and insert wire using pliers/cutters.
  19. Align Side (3) holes on PANEL (9) with Side (1) holes on a new PANEL TYPE 3 "PANEL (15)", and insert wire using pliers/cutters.
  20. Align Side (2) holes on PANEL (15) with Side (2) holes on PANEL PANEL (10), and insert wire using pliers/cutters.

Step 4: Preparing the Wiring

This build uses 6 Wire Ribbon cable and 2x3P connectors. The Headers have been affixed to the TYPE 1 PANELS. The cable will use 11 of 2x3P Sockets (10 sensors and 1 MCU terminator). Other instructions install the strain relief last; we use it as the first piece assembled and crimp the whole assembly (3 pieces + the ribbon cable) last step for each socket. After assembling the cables, they can be verified with this tester.

INITIAL SETUP

  1. Cut the 6 Wire ribbon 700mm.
  2. Keep the wire red marker or a named color (blue in the photos) consistently on the arrow marker on the connectors.
  3. Position the first felt tip mark 12mm from the end.
  4. Then place 9 marks at 60mm intervals from the first.
  5. Then one final mark at 120mm (or whatever slack you need for your build).

EACH SOCKET

For each of the marks do the following (from the left as in the RIBBON LAYOUT diagram):

  1. Link the Strain Relief and Middle part of the Socket to the right side of the mark.
  2. Loop the ribbon to the other side of the Middle part of the Socket.
  3. Link the Piercing part of the Socket into the other parts with points onto ribbon.
  4. Tighten slack out of ribbon and tighten Piercing part onto ribbon with fingers.
  5. Place Socket in vice and tighten till all pieces fully compacted.

Step 5: Connecting the Wiring

The sequence of the wires avoids the ribbon colliding with the MCU housing (adjacent to the power panel) and places the end terminator socket near the MCU breakout boards. The sockets and Headers have a keyed side so they can only be inserted in one direction.

  1. Insert the first Socket (left side one marked at 12mm) into the Header on Panel A.
  2. Inset subsequent Sockets into Header on Panel B through to Panel J.
  3. The last Socket will be plugged into the I2C daughter-board on the MCU unit.

Step 6: Next Steps

THE SCREW-IN COLLARS

The collars shown throughout this page are the quick install collars. The ASSIMILATE SENSORS can be pushed-in and pulled-off easily. If you need to secure the sensors for any reason, the screw-in collars can be used instead. The 4G x 20mm screw needs to be removed from the individual SENSORS, they are then pressed into the socket (the 3P Female Headers and Key), and a 4G x 30mm cap head self tapping screw is screwed through the collar into the sensor hole.


AFFIX THE BASE

The individual instructions for the different MCU varieties will supply the base and the housing. Assemble the base and housing as instructed.

Connect wires as instructed.Affix BASE to SHELL with 10 off 4G x 6mm self tapping countersunk screws.

THE SOCKET CAPS

When the Sensor Sockets aren't occupied, the caps offer some protection to the contacts. Rubbing a light oil on the 3P Female headers may stop them accidentally getting glued.

  1. Insert 2 temporary 3P Female Header on 2 3P Male headers to be installed.
  2. Add Cyanoachrylate Adhesive to the exposed short end on the 3P Male headers.
  3. Insert the glue end into the caps and press in firmly.

THE FEET

If the site for the hub is unstable, raised or inverted, you may want to fix it to a surface. The feet are supplied with the generic shell parts, but they screw into the base of the ICOS HUBS which are specific to a MCU/use-case. They can be screwed on the base in each corner at that stage.

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