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Designing and 3D Printing an Integrated Circuit Holder

3D Printed Integrated Circuit Holder

3D Printing / 3D Printed Integrated Circuit Holder

3D Printed Integrated Circuit HolderI spend way too much time on Aliexpress in the middle of the night. As a result, I’ve amassed a huge collection of assorted ICs. Who can resist a pack of 20 ICs for $1 with free shipping? Not me, that’s who. I enjoy making models and I have a 3D printer, so took a crack at solving the problem by designing and 3D printing my own IC organizer.

 

I designed it so that each compartment would hold a single 8-pin IC, and to use as little plastic as possible. Compartments can be added or removed to hold as many ICs as needed, and can be positioned into whatever configuration is desired.

 

I started by creating a basic design, which was just a box that was slightly larger than a standard 8-pin IC. More boxes were used to create the rough profile of an IC. Then I subtracted the IC profile from the original box using the Advanced Boolean tool. I added a notch  to each side of the holder to make it easier to add or remove ICs. Then I copy and pasted the individual holder until I had as many as I desired.

 

Printing involved exporting the model as an STL through 3DS Max. I imported it into Repetier Host, sliced the model using Slic3r and then I printed it on my Kossel Delta.

 

Here’s a video of the entire process, from initial design to 3D printing to being used.

 

I used the following printer settings:

  • 0.4mm nozzle width
  • 0.3mm layer height
  • 200C nozzle temperature
  • 103% extrusion multiplier
    • Better bonding and surface finish at 103%, but reduced dimensional accuracy
  • 120mm/s internal speed, 90mm/s surface speed
  • 25% speed first layer

 

Download the 3DS Max and STL files:

http://www.thingiverse.com/thing:2007972

 

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ProGrow Update #4 – SD Card, Analog Buttons & 3D Printed Enclosures

ProGrow Version 1.0

ProGrow Update #4

ProGrow Version 1.0
ProGrow Beta

 

I completely revamped the layout and configuration of the modules on the front of the ProGrow. I designed and printed some basic enclosures for all of the different little modules to help isolate each unit and tidy it up. It’s still a mess of wires, but I’m making progress on the overall design. I used 3DS Max to design the basic enclosures, and then I used my Kossel Delta printer to make them. Most of the things were printed using white PLA, but I ran out and used black PLA to print the 9V battery enclosure.

3D Printed Enclosures

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I’ve successfully added an SD card module to store data for the long term. I have a spare 16gb MicroSD in there right now, so I have a few years worth of samples that I could store. I’m going to change the SD card to a smaller, more robust one to help avoid catastrophic accidental corruption. I use the SPI.h and SD.h libraries in order to read/write to the SD card and I store the sensor data in a .txt file. I’m working on graphing the data automatically, but it’s not a priority right now.

 

4 Buttons Connected To One Analog Output
4 Buttons Connected To One Analog Output

I removed the 4 digital buttons that I was using for manual control. I made a circuit that outputs an analog signal instead of a digital one, and connected the buttons to a free analog pin. This freed up 4 digital pins for future use. I use a few series resistors to create different analog signals that gets sent out through the purple wire in the image above. The buttons are placed so that they will see different levels of resistance from the chain of resistors when pressed. The programming simply reads the analog value and then makes decisions based off of the value. Much more pin-efficient than before!

 

The LED display made the old RGB indicator light obsolete, so I removed it. This gives me even more digital pins for future use.

 

I’m going to work on reducing the power draw, and implementing batteries next. I’ll be publishing a parts list sometime soon.

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ProGrow Update #3 – Growth, Batteries and Mold

ProGrow Update #3

The ProGrow has been exploding with growth over the past few days. Some of the blades are over 6″ now, despite Ozzies constant attempts to eat all of it. The soil started to develop a very small amount of harmless white mold. I assume the mold is due to the consistently high moisture levels. I treated the mold by adding a trace amount of potassium bicarbonate and cinnamon to the soil, and to the water. The mold vanished in less than two days and the grass seems to appreciate it. I also reduced the frequency of automated watering to once every 6 hours at the most, and changed the moisture threshold that turns on the pump. This should help reduce the moisture levels of the soil, to discourage further mold growth.

ProGrow Update #3 - Batteries and Stuff
ProGrow Update #3 – Batteries and Stuff

 

Batteries

I tested the 18650’s that I had laying around, and only two of the batteries were still functional. The other two seemed to be almost completely discharged and are most likely at the end of their life. I’m going to use these two to create the new battery pack for the system. I still need to test the Macbook battery that I have to see if it’s a potential solution, but I prefer the 18650s due to their profile. I’m still waiting on the charging modules from Aliexpress, and it could still be a while. Once the charging modules arrive, I’ll charge up the batteries and do proper measurements to get an idea of their health.

18650 Batteries
18650 Batteries

 

I am considering moving the system from an Arduino UNO to an Arduino Nano. I believe that it would let me reduce the footprint of the project as well as reduce idle power consumption. I’ve received my SD card module in the mail and intend to implement it into the ProGrow as the next step. I am going to remove the RGB indicator LED in order to free up GPIOs for the SD Card. Ozzie seems to like hanging out right next to the ProGrow. It’s like a grass buffet for him!

Ozzie chillin' next to the ProGrow
Ozzie chillin’ next to the ProGrow
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ProGro Update #2 – USB Battery Bank

ProGrow Update #2 – Battery Bank

ProGrow with USB battery bank
ProGrow with USB battery bank

 

I’ve upgraded the system to include a USB battery bank. I’m using a cheap 4400mAh battery at the moment, but intend to upgrade it to a better system. I have a bunch of spare 18650’s and a MacBook battery that I could use, and I’ve ordered some charging and voltage step-up/step-down modules from Aliexpress to build a custom charger. I’m also going to invest in some solar panels to make the system recharge during the day, but I will need to find out my current draw and other things before I buy them. Right now the system requires too much power to have a realistic solar panel recharging system.

ProGrow Powered On
ProGrow Powered On

 

I ran into some initial difficulties using the battery bank to power the Arduino. The bank is designed for charging phones, it has an automatic shutoff feature if the output current is very low. During normal operation of the ProGrow, the battery shuts off after approximately 10 seconds if current draw is under 50mA. I had to make the automatic sampling time ~5 seconds, so that the LED display would turn on and draw enough current to keep the battery active. From 1/4 charge, the battery bank was able to power the system in its current state for ~18 hours. Not bad for a first run I suppose, but future versions will be much better. I’ll have to make a better battery bank and find out my current draw before I continue.

 

 

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ProGrow is under development… again!

ProGrow Development

I’ve just started work on my ProGrow system after quite a long period of inactivity. Surprisingly, everything on the ProGrow still worked when I first plugged it in after so long. The moisture sensors didn’t seem to accumulate too much corrosion, and everything was still reading properly. It even had the program still loaded. Pretty crazy, considering it’s made using the cheapest parts available, went through a move and has sat idle for 6+ months. The plant that I used to have in the system was very dead. I replaced the soil, added a layer of cat grass seeds and then put an inch of soil over top. I chose cat grass because it’s super cheap, grows like crazy and I have two cats.

ProGrow Day 7 Growth From Front
ProGrow Day 7 Front

DC Pump

I bought a 3V-6V submersible pump from Aliexpress. It cost approximately $2 for one pump! That’s pretty darn cheap. I tested the pump by connecting it directly to a ~6V 18650 battery bank, and it pumped like crazy. It seems to work fine with a 9V battery as well, so I ended up using one of those because I had plenty of spares. I’m going to implement a more permanent rechargeable battery bank soon, possibly with some kind of solar power.

3V-6V DC Water Pump
3V-6V DC Water Pump

Relay Module

I added a double relay module to the project ( also bought on Aliexpress ), and connected the inputs on the module to digital pins 12 and 13 on the Arduino. It gets 5V and a ground connection from the nearby breadboard that holds the button inputs. A 4 digit segment display was added to the front to display the current sensor readings, instead of sending the information through the serial connection. I bought the display from RobotDyn on Aliexpress ( big surprise ), and it uses the arduino-tm1637-master library. Currently it displays the temperature, air and soil moisture, ambient light, run time and the delay between automatic samples. It also displays the project name and some other stuff while turning on.

ProGrow Day 10
ProGrow Day 10 with relay & LCD

Watering

I attached a mason jar to the side of the container in order to act as a water reservoir. With some hot glue and double sided tape, I attached the pump to the inside and ran some wires. I attached the pump to a 9V battery, and connected that to the relay that is controlled by pin 12 on the Arduino. I use the values read from the moisture sensors in order to control power to the pump. When the soil moisture falls below a certain threshold for a certain length of time, the pump will engage and water the plant until the average moisture rises back up. I plan to add another sensor to indicate when the water level is low in the reservoir, so that it won’t burn out the pump if there’s no water.

ProGrow Day 11 Status
ProGrow Day 11 Status

 

I intend to remove the RGB LED on the side to free up 3 more GPIOs. This will give me extra pins for future use. I am also going to move the relay modules to different pins.

I’m going to try to design and 3D print some customized enclosures for the modules that I have added. When my wireless chips and SD module come in the mail, I am going to implement wireless data logging and communication. I’m also looking into purchasing a sensor expansion board, and some silicon boards to clear up the wiring a bit. Not sure if the name “ProGrow” is going to stay.

I’m also going to try to make more detailed posts about the individual steps at a later date.