Development

Week 1, 13 May to 17 May

In this week, we consolidated the ideas we had since March 2019 ideas and had a few more from Dr Ho Shen Yong, Principal Lecturer, School of Physical & Mathematical Sciences, and Mr Tony, Lab Manager of the Making and Tinkering Lab. These are the ideas that we have:

1. Device to detect when a vending machine is empty and alert the vendor/supplier to top up
2. Intelligent sensor system for ease of data collection
3. A system to control the height of a helium balloon
4. Mapping the underground rat burrow network by tracking the movement of rats
5. An automated pot planting system for domestic usage, able to water the plants and apply fertilisers automatically

This week, we finally decided on idea 5 and decided to develop on this idea regarding gardening/growing. After plenty of discussions with Dr Ho and Mr Tony, we decided to work on this idea and come up with a modular planting system for domestic usage.

Week 2, 20 May to 24 May

After much discussion, we finally decided on the idea of automating the growth of strawberries in a domestic home setting in Singapore. This will be done using sensors to detect crucial variables such as soil moisture, light intensity, humidity, temperature, etc. Each variable will have an output such as water, full-spectrum light, humidifier and a cooler system. We started to decide which parts to buy and spoke to Tony regarding the details and things to take note when buying parts as none of us has any prior knowledge of electronics.

Things to take note:

1. To get parts that operate around the same voltage for simplicity when connecting the devices.
2. To make sure the parts are programmable using Arduino or Raspberry Pi

Week 3, 27 May to 31 May

In this week, we came up with Design 1 which was the system we all agreed on (see design page). However, we decided later to discard the idea of a rotating motor system since our entire system would be too small and a rotating motor system would not be ideal for a farm at such a scale. We then used the remaining time to come up with Design 2 (see design page) that took away the rotating motor systems and had a modular system in an aluminium profile instead. This design had drawers that contain the soil and plants with a storage compartment for water and fertilisers.

We also started looking into the ideal conditions for growing strawberries and the various factors to consider during the stages of growth.

These are the things we found:

1. Strawberries usually grow runners out from the main plant.
2. The ideal depth of soil for strawberries would be about 15cm to 20cm (about 6 inches).
3. Strawberry plants thrive in well-drained soil.
4. Pollination of strawberry plants is usually done by bees or by the wind.

These factors mean that in our design, we had to factor in space in the horizontal plane to allow the runners to grow out. We also had to take the height of our prototype into consideration for the plants to grow vertically. We also need to have some form of a drainage system for the water to drain properly.

Week 4, 3 June to  7 June

On 6 June 2019, our group had our first project update meeting. In this presentation, we introduced our idea to Dr Ho and fellow students who attended. Most of the feedback given were regarding the ideal growing conditions of the strawberry plants and how we were going to regulate and control such factors. Since we have not really figured that out, we had to discuss solutions to solve such problems.

We also contacted local domestic farmers to find out more about growing strawberries in a small scale household setting. Questions we had in mind would be regarding pollination since pollination of strawberry plants were usually done by bees and natural elements such as wind. However, proper answers were not delivered to us.

We began to purchase items from various online companies such as:

1. SGBotic – Sensors and electronics, Raspberry Pi 3B+
2. Lazada – Pumps, motors, full-spectrum light, Arduino, miscellaneous
3. Mizu Gardens – Fertilisers
4. Monotaro – Soil
5. Refrigerator

Before purchasing the items, we made sure to consult Mr Tony to ensure that the correct part is bought and can be used for our project. Mr Tony was the one who suggested for us to use a refrigerator to regulate temperature as building a large, enclosed cooling system from scratch within this limited time period would be time-consuming.

Week 5, 10 June to  14 June

This week was mostly waiting for our parts to arrive. Time was spent mostly on discussing the designs using Fusion360 and how we were going to incorporate the sensors and output components into the prototype design. Our initial plan was to purchase half grown strawberry plants from overseas since they were not available in Singapore so that we would not need to grow them from the seed which would take a very long time. However, half grown plants were also expensive and they require a long shipping time, which would not guarantee their survival upon reaching our lab. Hence, we decided to do things the hard way and purchase various species of strawberry seeds so that we can grow them.

Week 6, 17 June to  21 June

This week, most of our sensors arrived and we started to experiment with the sensors using the Arduino units borrowed from the Making and Tinkering lab. These are the sensors that we managed to get working:

1. CO2 sensor – Units of the values given were unknown.
2. Lilypad light sensor – Light sensor was able to produce readings. However, units of the values were unknown.
3. Temperature & Humidity sensor – Absolute temperature was available for both temperature and humidity. These values can be displayed on the Arduino LCD screen.
4. Soil moisture sensor – Able to obtain analogue readings with a range. The range is classified into low, medium and high humidity.

Week 7, 24 June to  28 June

In the beginning of week 8 (24 June), we welcomed the arrival of strawberry seeds and the humble beginnings of the growth of strawberries began!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Plants are labelled 1A, 1B which are grown outside the fridge in the M&T lab and 2A, 2B which are grown in the fridge in the M&T lab.

 

Week 8, 1 July to 5 July

We managed to get the components working together. The three factors we are focusing on for now are:

1. Soil Moisture
2. Temperature
3. Light Intensity

Soil Moisture

We managed to get the soil moisture sensor working on the Arduino such that it provides analogue values of soil moisture. These values are classified into low, medium, and high moisture. Next step would be to programme the Arduino such that the water pump gets activated when the moisture falls below a certain level, and switches back off as the sensor detects an increase.

Temperature

Temperature sensor works with the relay such that as the temperature goes above a certain value, the relay will be switched on. Otherwise, the relay remains switched off. Next step would be to connect the relay to the fridge!

Light intensity

We are still awaiting the arrival of the 12V lights that we ordered due to unforeseen circumstances. However, we managed to get the light sensors working by displaying light values on the serial monitor with the units unknown, so yay!

If we manage to get these variables working properly, we would explore other variables such as humidity and CO2 levels.

Week 9, 8 July to 12 July

This week, the 12V LED lights arrived and we managed to obtain the code for the LED lights to start working. We are able to vary the intensity of the LED lights from a range between 0 and 255 in the Arduino IDE.

To do: Get the LED lights working with the lilypad light sensor.

Week 10, 15 July to 19 July

This week, we had a number of accomplishments. Most of the strawberry plants we grew began to germinate. However, the seeds that grew belonged in the cup that was outside of the refrigerator in the M&T lab. This is because for that seed species, the germination temperature was between 20°C to 25°C, which was the temperature of the M&T lab. The temperature of the refrigerator, however, was cooler and go up to -9°C.

 

 

 

 

 

Moreover, the 12V full spectrum lights were connected and we programmed the lights to be switched on for 8hours a day. The lights will then switch on and off automatically according to the time, instead of according to the light intensity which was originally planned.

 

 

 

 

Because the growth of strawberries from its seed will take too long, we purchased strawberry plants already half-grown. These strawberry plants will be placed in the refrigerator when the code is complete so that the variables can be regulated to ensure the survival and the growth of the strawberry plants and hopefully, eventually fruit.