-- What does it do? TruRow uses sensors to measure a rower’s power output in a boat. It takes potentiometer measurements and calculates the angle the oar makes over one stroke and also calculates the force applied to the oarlock itself by the oar. The oar acts as a lever arm, and pushes against the oarlock during a stroke.

I chose to use the waterjet to make my part (was going to use the EDM but there were some technical difficulties) I plan to make an oarlock for my rowing system. It will be made of aluminum and it’ll hold and oar made of steel pipe. I made it fairly thick on the edges so it could withstand a lot of applied force. The waterjet was super cool to watch- really big machine:

I used pyqt to create a simple GUI to interface with my OLED screen. The user can type in values to a text box and click a button that sends these values to an OLED screen. I had to import QtWidgets like this and then write QtWidgets.QApplication..etc from PyQt5 import QtWidgets instead of like this because of an error I was getting with the way I installed pyqt on my linux machine (it was something to do with pylint not pyqt itself (pylint is a code cleaning tool))

These are the repos for the cpp and javascript: git@github.mit.edu:premila/eds_cuttlefish.git git@github.mit.edu:premila/eds_ponyo.git ponyo atsamd51j19/src/hunks/pins/hunk_pin_pa12_output.cpp ponyo/atsamd51j19/src/build_bootstrap.h PlatformIo and ponyo setup Add hunk class (example code hunk_pin_pa12_output.h, hunk_pin_pa12_output.cpp) and add to build_bootstrap.h Somehow make that cpp code on the board Create .js code for hunks, under :cuttlefish/hunks/interface Add hunks with inputs and outputs connected to toggle and errlight to output to LED hunklist[hlc++] = "driver/errlight"; if (type == "driver/errlight"){ ret = new Hunk_ErrLight(); } Writing Jake’s code to the module board:

The long term goal is to send data from my load cell and pot to an SD card and then printed out results on an OLED screen. For this week I just played around with the oled screen and got it to work. In section 10.1.1 of the attiny44 datasheet, there’s a few paragraphs explaining how to configure pins and how to use, if necessary, the internal pull up resistors.

This week I sent data from my load cell and pot to an SD card and then eventually will print out results on an OLED screen. I used a microSD card adapter to send data through SPI and then parsed and did calculations in python and passed back info in readable form to the OLED screen. Here’s the schematic for how the microSD adapter hooks up to my microcontroller. Communication does not work because you can’t trigger the pins up and down fast enough due to timing, most likely because of extra caps and resistors.

This week we learned about embedded programming and experimented with different environments and languages to program our boards. I progammed my board to help with my final project, which uses sensors to get data on rowers in a boat). I plan to measure angle (angle of the oar throughout the rowing stroke) using a potentiometer. I connected the potentiometer to Pin A3 on my attiny44 and programmed it to send pot values in a constant while loop through the Ftdi.

This week we made something big, or around 4 by 8 feet in area. I had a really hard time brainstorming ideas because most of my experience is using very small parts or is all in software. Some ideas I thought about were a table or a bench/chair for my room, but I really don’t need or have the space for more ‘furniture’ in my room. I was thinking of other relatively large objects I had seen recently and I remembered seeing an easel in an art workshop.

This week I worked on getting my system to get data from a load cell and make calculations. I used a DYLY-103 50 kg load cell and a SparkFun Load Cell Amplifier with an HX711-IC on it. To avoid making a new board since I would likely have to redo everything in the next few days/weeks anyways, I soldered magnetic wires to my attiny44 so I could easily connect to the load cell amp board and then to the load cell.

I wanted to mold and cast an “oarlock”, which a piece necessary for my final project. An oarlock is the fixture that the oar is placed in, the sensor to detect force and angle is placed on the oarlock, which moves coincidentally with oar. I used solidworks to CAD the oarlock, a very simple but functional design and then exported to HSM to do all the toolpathing before exporting to the machine.