Introduction: IOT123 - I2C PCB RAILS

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

Where durable casings are not needed, the ASSIMILATE IOT NETWORK SENSORS and ACTORS can stack more efficiently and with less resources and effort, straight onto minimalist rails. The encasing cylinders can be used (as shown in this build) or the underlying bricks can be plugged in directly.

The two components are:

  1. A Primary Rail which has male headers for the D1M WIFI BLOCK (or a D1 Mini with the headers applied correctly) and a single socket for a IOT123 BRICK or an ASSIMILATE SENSOR / ACTOR. This includes the pullup resistors for the I2C lines.
  2. A Secondary Rail with 2 Sockets. These can be daisy chained, and if using IOT123 BRICKS only, extra sockets can be added to each PCB.

The mounting and joining of the PCBs is entirely customizable, though I have provided simple examples.

Step 1: Materials and Tools

  1. Double Sided PCB 3cm x 7cm (2)
  2. 4K7 Resistors (2)
  3. 3P Female Header (6)
  4. Male Headers (8P, 8P)
  5. Hookup Wire (~5)
  6. Tinned Wire Ø0.5mm (~30cm)
  7. Solder and Iron (1)
  8. 4G x 10mm Pan Head Self Tapping Screws (8)

Step 2: Assembling the Primary Rail

Generally if a wire is in a through-hole I will solder it even if it is not a termination. Conversely if tinned wire run adjacent to pads I bend the wires so they are not touching the pads.

  1. On the top, insert the components 8P Male Headers (1)(2), 3P Female Headers (3)(4) and solder off on the bottom.
  2. On the top, trace a red wire from RED1 to RED2 and solder off on adjacent pins on bottom.
  3. On the top, trace a orange wire from ORANGE1 to ORANGE2 and solder off on adjacent pins on bottom.
  4. On the top, trace a blue wire from BLUE1 to BLUE2 and solder off on adjacent pins on bottom.
  5. On the top, trace a green wire from GREEN1 to GREEN2 and solder off on adjacent pins on bottom.
  6. On the top, trace a black wire from BLACK1 to BLACK2 and solder off on adjacent pins on bottom.
  7. On the bottom, trace a tinned wire from SILVER1 to SILVER2 and solder off.
  8. On the bottom, trace a tinned wire from SILVER3 to SILVER4 and solder off.
  9. On the bottom, trace a tinned wire from SILVER5 to SILVER6 and solder off.
  10. On the bottom, trace a tinned wire from SILVER7 to SILVER8 and solder off.
  11. On the bottom, trace a tinned wire from SILVER9 to SILVER10 and solder off.
  12. On the bottom, trace a tinned wire from SILVER11 to SILVER12 and solder off.
  13. On the top, trace a 4K7 resistor from WHITE1 to WHITE2 and solder off on adjacent wires on bottom.
  14. On the top, trace a 4K7 resistor from WHITE3 to WHITE4 and solder off on adjacent wires on bottom.
  15. Carefully affix screws in each corner ~1mm thread sticking through.

Step 3: Assembling the Secondary Rail

Generally if a wire is in a through-hole I will solder it even if it is not a termination. Conversely if tinned wire run adjacent to pads I bend the wires so they are not touching the pads.

  1. On the top, insert the components 3P Female Headers (1)(2)(3)(4) and solder off on the bottom.
  2. On the bottom, trace a tinned wire from SILVER1 to SILVER2 to SILVER3 to SILVER4 and solder off.
  3. On the bottom, trace a tinned wire from SILVER5 to SILVER6 to SILVER7 to SILVER8 and solder off.
  4. On the bottom, trace a tinned wire from SILVER9 to SILVER10 to SILVER11 to SILVER12 and solder off.
  5. On the bottom, trace a tinned wire from SILVER12 to SILVER14 to SILVER15 to SILVER16 and solder off.
  6. On the bottom, trace a tinned wire from SILVER17 to SILVER18 to SILVER19 to SILVER20 and solder off.
  7. On the bottom, trace a tinned wire from SILVER21 to SILVER22 to SILVER23 to SILVER24 and solder off.
  8. Carefully affix screws in each corner ~1mm thread sticking through.

Step 4: Joining the Rails

As mentioned before these can be daisy chained, though the instructions are for a single join.

  1. Line the PCBs up as shown
  2. Solder a tinned wire between each terminating wire on both PCBs.

This process can be repeated for more Secondary Rails.

Step 5: Next Steps

My original motivation for this was retrofitting previous builds with ASSIMILATE SENSORS / ACTORS. These builds had outer shells and there was no heed for elaborate device type housings (like the ICOS10).

Also since adding the RESET => D0 daughter-board on the ICOS10, prototyping/developing updates became a bit tedious, removing the ESP8266 from the housing on upload. This rail system is more light weight and accessible.

These considerations had an impact on me; maybe you have similar vistas...