13. Input devices¶
13.0 Assignments¶
Task: Input Devices¶
“The second half of the Fab Academy programme is designed to build on the previous weeks. You will be synthesising information and implementing skills that you were introduced to in the first half of the programme and encouraged to integrate these into your final project proposal.”
Group assignment:¶
- Probe an input device(s)’s analog and digital signals
- Document your work to the group work page and reflect on your individual page what you learned
Link to this week’s Group Assignment
Individual assignment:¶
- Measure something: add a sensor to a microcontroller board that you have designed and read it.
13.0.1 Learning outcome¶
- Demonstrate workflows used in sensing something with input device(s) and MCU board
13.1 Interfacing input device(s) to a microcontroller¶
13.1.1 Lessons learned from interfacing input device(s) to a microcontroller¶
13.1.2 Lessons learned on how physical properties relate to measured results¶
13.2 Design and fabrication¶
For my vacuum “Vacuum Glass Bell” project, I intend to create the smallest board possible in order to create a portable device; avoid waste of materials (in the form of copper plate’s real state), and the reuse of the highest amount of components possible.
13.2.1 Design process¶
13.2.2 Problems and solutions¶
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The browser selected for the use of modsproject.org could potentially be a source of problems when producing the milling file.
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Failing to align the cooper plate and milling bit to the exact X = 0 & Y = 0 position caused the final result to appear to be missing a portion. Although it could be fatal at times, for this specific board, was not the case.
USB Mini & Micro¶
The use of USB’s enables efficient access to electricity to function and the possibility for data exchange in and out of the microcontroller. The two main options are USB Mini and Micro. Both with advantages and disadvantages.
The teachers at the FabLab Barcelona have learned, overtime, that the best option is to use a USB Mini, as it is “easier to work with”. In the case of my specific board. For me “easier” is seldom better, therefore, after my previous “LED Molón Project”, I decided to switch to the “Micro” version.
The result was a smaller and yet “more difficult” component to solder: “No problem with that”.
Fig. #1. & #2. USB Micro PadSize Editing
The great difference came when the board fragility was tested several times, only to fail 100% of times. I sense am learning a lot, though.
13.3 Programing¶
13.3.1 Programing process¶
Pending…
13.3.2 Programing problems and solutions¶
The disadvantages of corporate owned technology¶
Microcontrollers are generally produced by companies who own the proprietary rights, allowing
consumers only partial access to the product’s data and information.
During the FabLAb Barcelona’s lecture on “Input Devices” we were explained on how
it is sometimes difficult to utilise Arduino for the programing of some microcontrollers
(i.e. the Atmel’s SAM D11C 14A microcontroller)
due to not being granted access to their corresponding libraries.
The quick fix¶
However, in some cases there is a way around. For the specific case of the SAMD11D14A, thanks to the work of Victor Barberan and Josep Marti from the FabLab Barcelona node, who were able to enable the Arduino libraries for the capacitive sensor of the SAM D11D 20-pin SOIC to the SAM D11C 14-pin SOIC by rightly editing the code given the similarities of the two microcontroller.
Fig. #3. “The quick fix”
Fig. #4. Arduino’s CapacitiveSensor Libraries
13.4 Files and code¶
13.4.1 Original design files¶
13.4.2 Source code¶
13.5 Video¶
13.6 Conclusions¶
To this moment in time I have been facing a vast array of problems that have kept me from being able to program the board I have created. Will continue working on it until success finds me.
Datasheet¶
Pad properties editing
- ArduinoCore-SAMD11C14A
SAMD11C14APinout
)
