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FlowIO Assembly Diary

Updated: Apr 7, 2023

Red means not fully prepared

Parts List:

  • all 3D printed parts

  • 1 Microcontroller Adafruit Feather Sense nRF52840

  • 2 Skoocom SC3101PM ( not sure how long it will take to get to Berlin)

  • 3.7V 350mAh LiPo Battery for pumps

Material List

  • Gorilla 2 Part Epoxy

  • Kapton Tape

  • Ultrathin Solder 0.3mm diameter

  • Solder Paste

  • Letter Paper

  • Desoldering Braid

  • Double-sided tape

  • Sillicone tube

Tools List:

  • 3D Printer:Ultimaker S3 and Objet260 Connex3

  • Office Printer

  • Soldering Station

  • Microscope for Soldering

  • Antistatic Mat

  • Desoldering Pump

  • Tweezers

  • Scissors

  • Wire Cutters

  • Wire Strippers

  • Vice Gripper

  • Mixing Rod (for epoxy)

  • Heat Gun (for Ribbon Cable Modification)

  • Fine grit file (for PCB headers)

  • Micro USB Cable

  • Pressure Gauge (for testing)

  • Soft Actuator (for testing)

  • Syringe

  • tube measuring guide

  • Manifold Plug Cover (DXF) (PDF)

Software List

  • Arduino

  • Adafruit Feather nRF52 Toolchain

  • FlowIO Library

  • FlowIO Firmware


Parts preparation

  • 3d printed parts

Print all parts with Ultimaker S3 (besides the valve cap and valve plugs)


Layer Height: 0.1 mm

Wall thickness: 0.8mm

Infill: 100%

Print speed:40mm/s

Travel speed: 80mm/s

Support structure: Tree

Support Branch Angle: 60°

Print Valve Cap and Valve plugs with Objet260 Connex3

setting: Defult

Wash it with Alcohol under 70%

  • Microcontrollor

Adafruit Feather nRF52840 Sense, 4516

If you are in Germany, you can purchase it on this website

  • Battery for pumps

LiPo Akku 3,7V Lithium Polymer Batterie 2-Pin JST-PH Stecker 350mAh 38x19x5,5mm

If you are in Germany, you can purchase it on this website

I didn't find the same Battery as mentioned in tutorial, but this one has similar size.

Material preparation

  • Gorilla 2 Part Epoxy

If you are in Germany, you can purchase it on this website

  • Kapton Tape

If you are in Germany, you can purchase it on this website

  • Ultrathin Solder 0.3mm diameter

If you are in Germany, you can purchase it on this website

  • Sillicone tube (ID*OD)

  • Microcontrollor Pre

Disolder the battery connector



Burn the bootloader ( 2h )

After following the tutorial for setup, I was about to burn the bootloader. But the Arduino started to report an error. At this point, I rechecked Adafruit's tutorial and realized that before the burning bootloader, I needed to press the RESET button on the featherboard twice to enter the DFU mode.

After entering this Mode, the round LED on the featherboard turns green instead of blinking all the time.

After uploading the hardware test example, the round LED will turn white, as shown in the image:

  • Valve pra ( 7h +24h)

During the stage of inserting the valve plug, I mainly hammered it in with a hammer. When the plug was almost fully inserted, I used the bottom of the handle of a tool to roll back and forth over the top of the plug until it was fully inserted into the valve.

When sanding the small iron piece at the bottom of the valve, it's actually not necessary to make it as smooth as you might think. As long as it reaches the level shown in the picture.

  • Main Driver Subassembly ( 2h )

This part was particularly challenging for me because I encountered two pins that were blocked. I heated them from the bottom, inserted the male pin, and then they were directly soldered onto it.

I'm not sure if it is technically correct, but it's working as intended.


  • Valves Subassembly ( 7h + 24 h)

I never would have thought that the most challenging part of assembling the valve would be this tube. The valve cap I received was too large in size and I tried to heat it to 160°C at the beginning, so this tube is died *_*

Therefore, make sure that your heat gun can reach a low temperature of 100 ℃. I purchased a new one , which took a week to arrive.

So, I used the valve cap that I had printed one size smaller, and it went in smoothly

I used a particularly useful tool with adjustable distance between its two clamps. With this tool, I was able to easily insert all metal locking brackets :)

  • Main Module Assembly ( 15mins )

  • Small Pump Module Assembly ( 30mins)

  • FlowIO Self Tests & firmware ( 30mins)


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