Recap
1. Measure Climate Change with Hydroponic System Blog #1 | Concept Design and Plans
2. Measure Climate Change with Hydroponic System Blog #2 | XMC4200 Bring-up and Hydroponic System
3. Measure Climate Change with Hydroponic System Blog #3 | XMC4700 + DC Motor Shield with Hydroponic System
4. Measure Climate Change with Hydroponic System Blog #4 | Sunlight Sensor and Water Purity
Highlights
This week, I looked at air flow. To perform photosynthesis, plants need carbon dioxide (CO2), water (H2O), and sunlight. First, a plant draws up water through its roots. The leaves take in CO2 and trap energy from sunlight. The plant uses the energy to turn H2O and CO2 into sugar and oxygen (O2). The plant uses the sugars for growth.
We covered the water and sunlight in the previous blogs. Let’s look at air and carbon dioxide.
Here is a list of highlights of Measure Climate Challenge #5 blog.
- Added a cooling fan to generate air flow
- Controlled the cooling fan by the Infineon DC motor control shield
- Collect some basil and mix them in smoothie
The pictures below are (1) development setup and (2) photosynthesis measurement setup.
Details
1. Added a cooling fan to generate air flow
I bought a USB powered CPU fan and cut the wire on the USB port. Then I connected the power and gnd to the Infineon DC Motor shield.
2. Control the cooling fan by the Infineon DC motor control
Good thing about this is the fan speed can be controlled by PWM value from the infineon XMC4700 microcontroller. The cooling fan is mounted on this tripod in the picture below. So, the plants can feel the nice wind.
The range of pwm is between 0 and 255. 255 is the maximum cooling fan speed.
3. Measure CO2 value
I also purchased a small CO2 sensor (link: CO2 Smallest sensors module - ELT SENSOR) to monitor the photosynthesis process. This CO2 sensor has I2C and UART interface. The Platform IO has I2C library for this sensor already. So, I just used the library to measure the CO2 value.
Inside void setup()
Inside void loop()
Now, the XMC4700 Microcontroller prints out the CO2 value by UART terminal
According to research, these are typical CO2 values as a reference.
To get plant's optimum level from the ambient air, typically 1100ppm needs to be added. The current value is 733pm. So, ideally about 750 ppm prefers to be added.
4. Collect some basils and drink smoothie!
Basil grew up now and I started collecting some and used them for smoothie.
Next Steps
I would like to add more python automation and photosynthesis related measurement codes for data analysis.