Introduction: IOT123 - D1M BLOCK - ADS1115 Assembly

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

D1M BLOCKS add tactile cases, labels, polarity guides and breakouts for the popular Wemos D1 Mini SOC/Shields/Clones. One of the issues with the ESP8266 chip is it has only one analog IO pin available. This instructable shows how to assemble the ADS1115 D1M BLOCK, which can add up to 4 additional analog inputs. If that is what you will be using the ADS1115 D1M BLOCK for, I suggest you use it in conjunction with the 2xAMUX D1M BLOCK(s).

The video above shows the process of assembling the pre-made blocks, compiling/uploading, and reading the values of the 4 analog sensors.

Originally the goal was to create an integrated multiplexer and breakout (the ADS1115 + 4 breakouts with the generic A, D, GND, VCC pins), but all attempts (~ 20 different designs with the protoboard) caused EMI related problems with the ESP8266. I have created a PCB design which may overcome this problem; I will report back when they are delivered and tested.

Step 1: Material and Tools

    There is now a full Bill of Materials and Sources list.

    1. The Wemos D1 Mini Protoboard shield and long pin female headers
    2. ADS1115 compact brick
    3. 3D printed Base and Lid, and labels for the ADS1115 D1M BLOCK
    4. A set of D1M BLOCK - Install Jigs
    5. Hot glue gun and hot glue sticks
    6. Strong Cyanoachrylate Adhesive (preferably brush on)
    7. 3D Printer or 3D Printer Service
    8. Soldering Iron and solder
    9. ~24AWG hookup wire
    10. 3pin male header
    11. 4pin male right angle header
    12. A 2.54mm Jumper Shunt

    Step 2: Soldering the Header Pins (using the PIN JIG)

    There is a video above that runs through the solder process for the PIN JIG.

    1. Feed the header pins through bottom of the board (TX right-left) and into the solder jig.
    2. Press the pins down onto a hard flat surface.
    3. Press the board down firmly onto the jig.
    4. Solder the 4 corner pins.
    5. Reheat and re position board/pins if needed (board or pins not aligned or plumb).
    6. Solder the rest of the pins

    Step 3: Soldering the Other Components

    1. Solder pins to ADS1115 with plastic spacers opposite to pin label side
    2. Place ADS1115 on topside (as shown) and solder on underside
    3. Place 3pin male header on topside (as shown) and solder on underside. Remove plastic collar and cut pins down even with pins from previous step. This is to ensure the jumper shunt is below the lid (for stacking other modules)
    4. Place 4pin male right angle header on topside (as shown) and solder on underside
    5. Hookup Side 5V pin to 3pin male header pin as shown (diagram red)
    6. Hookup Side 3.3V pin to 3pin male header pin as shown (diagram red)

    7. Hookup Side GND pin to ADS1115 G pin as shown (diagram black)

    8. Hookup ADS1115 V pin to 3pin male header pin as shown (diagram red)

    9. Hookup ADS1115 V pin to 3pin male header pin as shown (diagram red)
    10. Hookup Side D1 pin to ADS1115 SCL pin as shown (diagram green)
    11. Hookup Side D2 pin to ADS1115 SDA pin as shown (diagram blue)
    12. Hookup ADS1115 A0 pin to 4pin male right angle header pin as shown (diagram yellow)
    13. Hookup ADS1115 A1 pin to 4pin male right angle header pin as shown (diagram yellow)
    14. Hookup ADS1115 A2 pin to 4pin male right angle header pin as shown (diagram yellow)
    15. Hookup ADS1115 A3 pin to 4pin male right angle header pin as shown (diagram yellow)

    Step 4: Gluing the Component to the Base

    Once the pins have been soldered the remaining steps are the same for all D1M BLOCKS.

    Not covered in the video, but recommended: put a large dob of hot glue in the empty base before quickly inserting board and aligning - this will create compression keys on either side of the board.

    1. With the base casing bottom surface ponting down, place the soldered assembly plastic header through the holes in the base; the (TX pin will be on side with the central groove).
    2. Place the hot glue jig under the base with the plastic headers placed through its grooves.
    3. Sit the hot glue jig on a firm flat surface and carefully push the PCB down until the plastic headers hit the surface; this should have the pins positioned correctly.
    4. When using the hot glue keep it away from the header pins and at least 2mm from where the lid will be positioned.
    5. Apply glue to all 4 corners of the PCB ensuring contact with the base walls; allow seepage to both sides of the PCB if possible.
    6. On some PCBs where the board ends close to the pins, dob a large amount of glue onto the base to the height of the PCB; when this cools apply more glue on the top of the PCB bridging to the lower glue.

    Step 5: Gluing the Lid to the Base

    1. Ensure the pins are free of glue and the top 2mm of the base is free of hot glue.
    2. Pre-fit the lid (dry run) making sure no print artifacts are in the way.
    3. Take appropriate precautions when using the Cyanoachrylate adhesive.
    4. Apply Cyanoachrylate to the bottom corners of the lid ensuring coverage of the adjacent ridge.
    5. Quickly fit the lid to the base; clamping shut the corners if possible.
    6. After the lid is dry manually bend each pin so it is central in the void if necessary.

    Step 6: Adding the Adhesive Labels

    1. Apply pinout label on underside of base, with RST pin on side with groove.
    2. Apply identifier label on flat non-grooved side, with the pins void being the top of the label.
    3. Press labels down firmly, with a flat tool if needed.

    Step 7: Next Steps