Project Logs

Collapse

• Update 10/2023

  J Gleyzes • 10/04/2023 at 09:33 • 0 comments

  If you want to get the latest updates on the project. It continues on this hackaday page : https://hackaday.io/project/191799-ultratower-2023

• Quick Update 23/01/23

  J Gleyzes • 01/23/2023 at 20:52 • 0 comments

  The DC-DC Buck Step Down Converter problem

  I use this module (CN3903 3A) to convert 12V to 5V to power two components: the esp32 and the 5V mini pump.

  However, it is not capable of feeding both at the same time. After several tests, activating the pump causes the esp32 to crash.

  But separately everything works.

  Several solutions are possible: 

  • Put two CN3903 one for the pump and one for the esp32 
  • Take a 12V pump, allowing to power directly to the charger (but it is not a USB connector for the pump anymore)
  • Use a 5V charger for the PCB and then use a boost converter to power the disks at 12V

  For the moment I use solution 1 which allows me to test easily.

  Disc nut optimisation

  The old STL design, was too closed on the disk creating a water droplet retention preventing the creation of fog afterwards. The new design seems to solve the problem.

  New PCB

  I'm still testing the latest version of the PCB, the fog creation is good now I'm waiting to see if the disks don't get damaged over time.

• Quick Update 21/11/22

  J Gleyzes • 11/21/2022 at 15:48 • 0 comments

  I have been testing for several weeks a new circuit to create a better AC current with a current sensor to adapt the frequency.

  Schematic:

  By adding coil L7 and capacitor C13, the generation of alternating current is balanced in the negative and positive directions.

  Old circuit:

  New circuit:

  I also added a shunt resistor to measure the current. By changing the frequency we can detect the peak of fog creation which corresponds to the current peak.

  And for example for a disk sold with a resonance frequency of 108kHz the peak of fog creation is at 100kHz.
  

  I have ordered the new PCB with the modifications. I will test it before publishing it.
  

• Quick Update 03/11/22

  J Gleyzes • 11/03/2022 at 21:04 • 0 comments

  I changed the ESP32 code, the new code is in the project github.

  The changes:

  • The pH sensor reading switches from pin 13 to 35 because pin 13 is unusable in ADC when bluetooth is enabled
  • The code for activating the pump has also been changed
  • Other minor bugs fixed

  Water level sensors get damaged very quickly even when using the capacitive function of the esp32. I think I will use stainless steel wire to limit corrosion.

  The root system of plants is quite impressive. The lettuce on the top left has already been cut three times (leaving some leaves on). It has grown back to its pre-cut size in a week.
  

• Scalability

  J Gleyzes • 10/19/2022 at 19:02 • 0 comments

  The current design is great for a low cost tower and quick to build. But the discs can be used to water more plants. So a tower design with stackable tiers would allow to grow more plants.

  Here is the evolution of an individual tower but for building roofs we can still optimise

  Farm on a building

  The concept is a main reservoir that manages water quality (ph, nutrients, temperature). It is located high above the tower and allows the smaller tanks to be filled by gravity.
  

  Then there is an indeterminate number of ultratowers depending on the space available on a roof or other.

  The PCB of the towers only needs to manage the activation of the disks, the water level of their small tank and a valve to fill it and stop the filling.

  According to my calculation the cost for a PCB could be around 8~10€ for orders of 100 pieces. 

  There would be a single pump that brings the water from the bottom of the towers up into the large reservoir to close the loop.

  This farm concept would optimise material costs, running costs and electricity consumption.

• Video of the project

  J Gleyzes • 10/17/2022 at 16:47 • 0 comments

  And here is the video for the hackaday contest! Thanks again to this contest it motivated me to finish a project in three months instead of more than 1 year...

  
  

• Android Application

  J Gleyzes • 10/11/2022 at 12:01 • 0 comments

  The android application is online. You can download it on the google play store : https://play.google.com/store/apps/details?id=com.gleyco.ultratower
  

  This application allows you to change all the parameters of the tower without having to modify the arduino code. It also allows you to configure a data transfer to ThingSpeak. And most importantly, you can calibrate your sensors easily.

  I am not a professional developer, I only know how to develop applications in Kotlin for Android and unfortunately I could not make the application for IOS.

  For non android users I would make an arduino code where you can easily modify the variables.

• ESP 32 Code upload

  J Gleyzes • 10/09/2022 at 18:16 • 0 comments

  I have updated the code on github for the new PCB. 

  In this new version there is :
  

  • the pH sensor 
  • the EC sensor
  • the temperature sensors
  • the data sending to ThingSpeak

  The entire bluetooth communication routine between an android smartphone and the esp32 is also complete.

  This application, which should arrive this week, will allow you to modify the parameters of the tower (such as the time of the cycles, activate or deactivate the sensors, ...)

  But most importantly, the EC and pH sensors can be easily calibrated through the application.
  

• Applications

  J Gleyzes • 10/07/2022 at 20:51 • 0 comments

  UltraTower is a low cost ultraponic system under 100€ with parts that can be easily found in shops. Thus this technology can have several uses:

  On a balcony:

  Cities are getting bigger and bigger and have a garden to grow your own vegetables can be complicated. The tower is made of a 100mm diameter PVC tube which allows you to grow a maximum of plants (12) in a very small space.

  For Universities or Laboratories:

  The PCB is modular allowing the addition of a pH sensor, EC sensor, three temperature sensors and one humidity sensor. The sensors allow real-time monitoring of the data through the android app and ThingSpeak. This makes it easy to compare different crop variables to see which works best for certain types of plants.

  In a garden:

  This project is not aimed at eliminating the cultivation of vegetable gardens, far from it. But individuals who do not have the green thumb or the time to tend a vegetable garden can grow their plants passively thanks to this tower.
  

  On the roofs of buildings:

  To feed the cities, oil is needed to bring the crops to the plate. The roofs of the buildings are an unused surface of the cities allowing the culture of many plants directly in the cities thus limiting transport. Of course, an industrial adaptation of this tower is to be expected. I will detail it in another log.
  

  This technology has many possible applications, and I have only mentioned 4 but we could think of polar expeditions where the transport of fresh food is expensive,  in space and many more where traditional culture is impossible.

• Pump block

  J Gleyzes • 10/05/2022 at 20:39 • 0 comments

  As we have seen in this log, ESP 32 must manage the filling of the small tank at the top of the tower with a 5V submersible pump in the main tank. 

  The ESP 32 must however know the filling rate of the small tank as the disks must not run without water otherwise they will be damaged and the pump must be stopped when the small tank is full.
  To do this we will use only two wires and the touch sensor technology of the esp32. The esp32 has 10 pins that allow measuring the change in capacitance between the panel (sensor) and the environment. If you want to know more about how it works.

  Assembly:

  This is the top tank cover to which the pcb is screwed. 

  The blue arrow shows the bottom sensor.

  The red arrow shows the top sensor.

  The white arrow shows the connection on the PCB.

  The usb port at the top right of the PCB allows connection to the pump

  The code :

  touchRead(pin) ;

  This function returns a value between 100 and 0. By dipping a wire into the water the value will drop to around 10 allowing us to know if the high sensor or the low sensor is in the water. Before each activation of the disks, the bottom sensor of the tank is checked if it is not in the water then the pump is activated. A blocking loop will check the filling of the tank up to the low sensor if after 15 seconds the low sensor is not reached, the main tank is empty or the pump has a problem (the activation of the discs will not be performed). If the low sensor is reached, the blocking loop is exited leaving the pump activated. In the main loop if the pump is activated the high sensor will be mesured to know when to stop the pump. While waiting for the end of the filling process the discs will be safely activated.

  During the activation of the discs, the low sensor will be measured every 2 minutes in order to know when to fill the pump which is necessary when the user sets the disks to long activation periods.
  

View all 24 project logs