Category: David’s status reports

This week I spent time improving the 3d printed hardware design, previously it could come off if you swang the racket too fast. We didn’t test with actually hitting the ball because of this, we were afraid it could fall off. I made a new design that has a two part base that grips the racket better and screws together horizontally such that it doesn’t move around at all and shouldn’t fall off of the racket. I also resoldered all of the connections with solid core wire and much shorter wires. Previously our design had braided wires that were much flimsier and had poorer connections with the actual board, a few times they actually fell out and I needed to resolder them. I haven’t had that issue yet since the change, and I am hoping it doesn’t come up. 

We are now in the final stages of the project, I will be working super hard with my team to get the final bits of work done. The main thing I will be working on is capturing data, as this is the biggest blocker for getting all of our work to show effectively.

This week I spent some time talking to users about the product we are building, which was super useful. We did this some when we were initially getting started, but now I am doing more of it and finding it very useful as I start to think about this as a product and not just an engineering project. I also spent a good chunk of time looking into other similar products/projects on the market. I looked into products in the tennis space, pickle ball, and also golf. Golf is the most developed of the three, and although it is a bit different I was still able to learn some valuable things from looking into golf trackers/sensors. One anecdotal takeaway I had from this was potentially designing our sensor to screw into the tennis rackets instead of just press fit (this was taken from Arccos golf product). 

On the engineering side, I spent some time looking into IMU calibration with mario, and also started taking some steps to work on the bare component design. I have found bare components for the IMU and the microcontroller and I have started making a schematic to connect the two. I have also identified two manufacturing houses we could use for PCB assembly. I am not behind yet, but next week it is crucial that I place the order to manufacturer PCBs. 

My main goal next week is to place that PCB order which involved finishing the layout etc. I think I can complete this next week as well as help with data collection and adhere to the planned schedule. I do not think there should be anything that will impede my progress.

This week I finalized our (prototyping) component selection, I ordered an IMU and a microcontroller. I did some work to make sure these would be compatible, and that initial prototyping would be viable with these components. I ordered dev boards for easy set up and prototyping ease and I made sure that we could also get just the bare  components as well. It was a bit of work to narrow my list of components down to options that had both dev boards and bare components available. I looked for parts with significant quantities available on digikey to ensure that once we had the prototype working, we could order a bare component of the same device. Although the dev boards may be too large and heavy to fit some of our weight and size constraints we set for our final product, they will allow us to set up prototyping and data collection quickly which is the most important thing for us in our stage of the project right now. I have begun doing CAD for 3d printing a test rig that will attach the two boards to the tennis racket for initial data flow and testing 

Our progress is still on schedule; I submitted in the order to pay for two day shipping for the parts I ordered so that we would get them in time to use them over the weekend but unfortunately I was not notified to pick them up yet which is unfortunate. This has slowed our expected progress a bit but it is okay, we are not behind our planned schedule. 

If the parts aren’t available for pickup on monday we may have to think of other ideas to simulate our data flow to keep progress moving. This coming week I hope to have a physical prototype to test our data flow and data collection process.

This week I practiced and gave our initial presentation, and then the rest of the work I did was on selecting hardware components to use. I looked into IMUs and microprocessors that we could use. I also did a bit of research into how we could make the whole part waterproof, we could use a pogo push pin connector for charging and then put the rest of the electronics in an epoxy. 

I am making it a priority to select and order parts on Monday so that we can start prototyping as soon as possible. I am still on schedule for now. I plan to order parts on Monday and hopefully be able to get a working rough prototype by the end of this week or early next week (somewhat depending on part lead times and ordering process).

I think the STMicroelectronics LSM6DSV is the IMU we will use, but I am working to confirm that we can get both a good dev board for prototyping and an individual component later on for connection to our PCB we design.