Assignments

Complete your final project tracking your progress.

• What tasks have been completed and what tasks Remain ?
• What has worked, what hasn’t ?
• What questions need to be resolved ?
• What will happen when ?
• What have you learned ?

Status at the time of the Week 19¶

The vermicomposter itself is ready, here is what remains :

• LEDs panel (PMMA)
• Collector tray to retrieve the Worms juice (done for wildcard week)
• Find a way to use DHT22 without the DHT library (to big for the ATTiny44 !)
• Write the arduino code for the DIY moisture sensor
• Improve the reliability of the DIY moisture sensor
• Worm juice tank holder

Composites¶

I was able to finish the composite work this week. I was late on it but it worked finally fine.

Electronics & communication¶

I Had many difficulties making the communication work, even more as I am using one board to read both the capacitive (moisture) and the DTH22 (temperature). First I tried to send the values separately but finally I found it easier to create a message containing all the values and it works.

During the input week I used a C++ code to read a capacitive value, now I need to transpose it in arduino language.

Reliability of the DIY moisture sensor¶

I based on the Neil’s advice to make my own moisture sensor with a capacitive circuit. I experimented it during the input week using an ATTiny44 board programmed in c++. I tried calibrate it because, but currently the values are very fluctuating.

Worm juice tank holder¶

Currently the worm juice tank stand one the ground, but it would be better if ie was hooked on.

Questions about the final project¶

• What is the right method to calibrate the DIY moisture sensor ?
• Does the worms like the fan? They don’t like noise and vibrating, so I need to observe the population changes during use
• How to think the electronic parts? Currently, for the FabAcademy i use 3 DIY PCB boards. But for the future, I think about only one board with several microcontrollers, and which one to use?(ATTiny 85, 44, 45, 328p…)
• How to weigh the mass of composted waste? I did not set it as a goal for the fabacademy, but later I would like to be able to weigh the amount of composted waste.
• How will the wood evolve over time? The poplar plywood to make the trays is not suitable for moisture. I must observe how it will evolve and if the treatment of linseed oil and turpentine oil will preserve a little the wood.
• How to lower the cost I have identified potential tracks to lower the cost (removal PMMA and fan…) These tracks should be confirmed during the use of this first prototype.

Schedule for the final project¶

Done for the fabacademy¶

• LEDs panel (PMMA)
• Collector tray to retrieve the Worms juice (done for wildcard week)
• Find a way to use DHT22 without the DHT library (to big for the ATTiny44 !)
• Write the arduino code for the DIY moisture sensor

Improvement clue¶

• Improve the reliability of the DIY moisture sensor
• Worm juice tank holder
• Think about how to weigh the mass of composted waste?
• Re-think the electronic parts
• Evaluate whether or not I keep the fan

I still have issues on electronics, hope it will be able to communicate properly, my last delay for it will be on the 16 of June, the Lab is opened all day for us.

FabAcademy learning outcomes¶

Tools and documentation¶

Previously, I had never created a website or used git. Thanks to the documentation work I learned not only to better document but also to use the various tools necessary for the creation of online content (gitlab, Atom, ImageMagick …)

Electronics and programming¶

Thanks to the fabacademy I learned a lot about electronics. The different cards produced allowed me to discover and master Eagle (basics!), to familiarize myself with the different electronic components and their functions. I also develop my welding skills through the different PCBs produced.

All problems met with serial communication have made me progress in programming. On this subject I thank Adrien and JB, my colleagues, who helped me on this subject. The time spent understanding Neil’s code for capacitive measurement and its implementation in Arduino allowed me to take a first step in the C ++ language.

Working with the ATTiny44 I had to adapt to its characteristics and put aside the systematic use of library. This is how I searched the library of DHT temperature sensors for use without libraries and save space on the microcontroller.

Molding and casting¶

I had not done too much molding, the fabacademy allowed me to confront it during the wildcard week and week 10. I learned about different products and techniques. In particular thanks to this site

Fusion 360¶

I used to use Fusion 360 before the fabacademy. However, I used the model module more than anything else. Working on the Badgebot for the machine design week, I experimented and learned how to use form and patch modules. This opens up new possibilities …!

I also learned how to link PCBs designed with Eagle into fusion to integrate the electronic boards into the fusion projects.