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obtaining data from a car
Sunday, August 31 2025
location: 940 feet west of Woodworth Lake, Fulton County, NY
I took a recreational 150 mg dose of pseudoephedrine today to make it that much more, well, in keeping with vacation. I also like to drink on vacation, of course, but I always find alcohol binges tiresome after a couple days.
The dogs had grown impatient and gone on their own walk this morning, something they almost never do. When they got back, I felt bad about it and took them (though I think only Charlotte went) for another walk for a fairly lame walk down to the lake and back.
With that out of the way, I went back to working on something I'd attempted months ago: getting an ESP8266-based NodeMCU to communicate with the Chevy Bolt via its OBD2 system. I'd wired it up once before and had ChatGPT come up with an Arduino sketch, but I'd never succeeded in getting any data at all; it reminded me of all the doomed attempts I've made to get data from the Navien boiler using RS-485. But today before I even began, I detailed how the NodeMCU was connected to the MCP2515 CANbus device. I then looked for how the MCP2515 was supposed to be wired to the OBD2 connector. It was then that I realized I'd wired it to the wrong pins on the latter. (I'd followed something I'd found online; it must've been wrong.) Once I had everything wired together the way I thought it should be, this was how it looked:
INT->GPIO16
SCK->GPIO14
MISO->GPIO12
MOSI->GPIO13
CS->GPIO15
(GND and VCC are also appropriately connected)
Pin H on the MCP2515 connected to pin 6 on the OBD2 connector
Pin L connected to pin 14 on the OBD2 connector
I then had ChatGPT write me a sketch that I took out to the Bolt and tested with a working connection via OBD2. This didn't produce data, but the results were promising. A switch from the use of an interrupt to polling finally got me some velocity data (0 km/hr of course!). Then I had ChatGPT do some internet research to find how to get battery percentage data (the main information I wanted) from a Chevy Bolt. When I ran the resulting code, I started getting an integer that was proportional to the charge percentage. This was huge! The only problem was that I had no way from the OBD2 connector to turn on the OBD2 system; for that I will have to hack a switch in series with the driver-side door switch to simulate that door opening whenever I need data.
This evening I took a beer down to the lake a little before sunset and was sitting on the dock when a large bird made a spashdown four or five hundred feet to the southeast. It was Throckmorton the Loon! I'd seen loons take off from different lakes many times but this was the first time I'd ever seen one land. Somewhat surprisingly, he didn't announce his presence but immediately began fishing beneath the glassy surface.
In among other things, I've been gradually covering all the exposed styrofoam in the basement entrance bulkhead with old CDs and DVDs. I'm done covering all the places that can be covered by a whole CD and now have to cut them into fragments to fit in various spaces. There are a lot of small triangle-like shapes between the CDs that will probably never be filled, but there are also larger spaces along the edges. I was thinking I would eventually cover the CDs with portland cement, but the other evening when I was mildly stoned, I sat between the two walls of CDs and loved how they looked just the way they are. Given all the information encapsulated in those CDs, I wonder if someday they will provide valuable fragments of documents from this period, much like old palimpsests now covered with Bible passages are the only source of some ancient Greek writings.
For entertainment, I've mostly been using a small battery-powered radio that can also play MP3s via USB or microSD card and connect via bluetooth. I like that it has an analog volume control and an analog tuner, which is a lot easier for quickly getting to a station than a push-button digital interface. Also, the single-cell lithium battery seems to provide hours of run time. The audio isn't great, but it's better than any of my laptops. I'm always looking for the perfect portable audio entertainment device, and this thing comes close. I got mine on eBay for about $20 and got it after having good luck with an identical one back in Hurley that I have only used for its FM radio.
Neville on the dock this evening. Click to enlarge.
For linking purposes this article's URL is:
http://asecular.com/blog.php?250831 feedback
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