WORK ACCOMPLISHED:
Further research into part compatibility has demonstrated the following problem. As we are already facing budget concerns, we are very mindful of any increases to our total costs. I discovered that the battery we selected does not come with a bms or battery management system, a critical component for obtaining live data with regard to battery charge. As this was one of the core requirements we set out for ourselves, we want to push to accomplish this goal.
Our current battery is 10s2p which means 10 in parallel, 2 in series for a total of 20 batteries at $90. Moving to a pack with a bms even at 6s2p, which is 12 batteries brings us up to $185 as seen here: https://www.mboards.co/collections/batteries/products/6s-p42a-battery-pack-transparent-series with very little opportunity for other options.
As a result, we remain undecided.
We consistently have to make tradeoffs between reputation and performance. For instance, we are able to buy more powerful motors with hall sensors here https://www.amazon.com/Brushless-Belt-Drive-Balancing-Scooters-Skateboards/dp/B07RXWW3DS/ref=sr_1_12?crid=2NEHK9FI43FHT&dib=eyJ2IjoiMSJ9.6_nUl4ZD3ZhjtZRfEZjPpPkI-0W-ird_zf3qSUvrDoYUGkNTVwylh-QgjidNUhGbBe8Qa_XTIE045heaKbB5qKbSCZ6tp3QndVmnl9liKLtqRwtL1AC–_CNs96VuNbYgxfPJvtUo_kl6qI-aVew-xXCn2bupq9aYjwABIzz8FzucCxE36cwUdnpagXtLfcBK5erniMT3015ZyDPIe9Mm4gaoM9hpidCoyrb6UavlVlui1HrwVHDXP2RGIHHI577Q3uZjiODNIhXDbX7rnCcJO6g-03lSZ_WOywLBtRB8rw.E1N2p-XUPUVELYuiIRbatHIXFuBrgDPEFet7I_SFGso&dib_tag=se&keywords=skateboard%2Bmotor%2B6354&qid=1727576364&sprefix=skateboard%2Bmotor%2B6354%2Caps%2C116&sr=8-12&th=1
but without the ratings and brand reputation that our other option gives us.
On top of this, I researched the charger for our battery, antispark switch to power the board, and explored the wirings for our VESC and made note of some converters we will need to purchase.
I also looked into the truck/motor mounting system and found
which we will likely use as it appears to be relatively plug and play
DISCUSSIONS:
I researched the communication methods between the Rpbi and VESC and landed on using UART. Theoretically, we can use UART to send motor speed, temperature, and others to the Rbpi and receive throttle, braking, and other commands back. There is a python module called pyvesc that will allow us to do this seamlessly.
The VESC does not explicitly list compatibility with UART but says it is compatible with VESC software. In the case it is not compatible, we will definitely be able to send PWM signals to the motors from the VESC using RPi.GPIO python module and the GPIO ports on the Rbpi.
I also discussed path planning with Tio and the team and landed on a project of GPS down to a 2d box in which we will use basic x,y coordinates to reach the target.
PROGRESS:
I am still on track as my task this week was to select the path planning algorithm.
NEXT WEEK’S DELIVERABLES:
Next week, my sole goal is to fully and completely finalize the parts list. There is still considerable work to be done on this front and I hope we are able to get this done so we can move on to the actual implementation. This has proved to be significantly more difficult than expected.