Gripless

For those that program on embedded hardware like Esp32. If you send a html header for “Content-Encoding” with a value of “gzip” first then you can send compressed data rather than html plain text. Ive just got a small script that read the .html files in the project folder and saves a copy with .gz or .txt containing a c byte array which can be copy pasted into the c source. This is obvious if you know anything about the internet, but I just hadn’t looked at it since I was still trying to get things working. Even for my small pages this on the browser side reduces 8k to 1.2k. While this isn’t really large amount of data by modern standards, it is noticeable on the user side in browser having the page appear quicker. Since even the 10 year old android I’m, testing on has 4x 1.5ghz and 4x 2ghz cores, compared to the esp32 with 1 or maybe 2 cores at 240mhz. The decompression is faster on the phone cores than the delayed in sending more data by the slower esp32.

Bluetooth Low Energy 5.0 aka BLE 5 sensors finally arrived after getting lost at the airport for 3 weeks. Tested them and for the record are the same as the most common sensors (#2 in previous post) for data and how they work. Physically externally they look very similar too. The only difference in the specs is the power use is around 30-40% less. This is likely correct as the power is mostly in the Bluetooth transmission and ble5 is lower wattage than ble4. The manual is also just a copy with a few spec and details changed. Though the did miss changing a few ble4 references. Good news for me and anyone else using those sensors if the receiver is ble5 there’s now need to change anything and they just work. This may also apply to OEM devices as ble4 hardware is old and may have already been substituted to ble5 during later production as it is backwards compatible.

While not total disasters, they are still a little risky. This one even has the wrong components fitted. I’d stick to brand name or at a minimum a little more expensive devices. The op-amp chip in this one is the same physical package as common canbus transeivers. Just in a transceiver there is a lot more protection and isolation to protect the canbus and device from each other. Thought the cost is at least 50x higher, possibly 2-500x higher.

So far they seem to have exclusive access to Subaru, Suzuki etc diagnostic tools and Subaru support (eg unlock codes). Almost every garage I called gets parts from them in the region so they set prices. Not all parts are actually genuine! They get cheaper parts and don’t tell you, which I found out today from their parts department. But those cheaper parts arent sold much cheaper. Not to mention the $250-375 scanning fee for diagnostic if they don’t know what the fault is already. Though services include a scan for cheaper. Combined with nearly $250 an hour labour rate seems like they are really milking it.

Well turns out JavaScript is more hassle than c. Finally after a couple of days the TPMS scanner now sends a nice webpage with a sorted list of discovered sensors. So all you need to do is select which one and which number you want it save it as. The current arbitrary limit is 16 sensors that it will learn. The c code is a single line #define sensor-count 16 to change but the JS isn’t linked so has to be manually updated at the same time. The last piece is how sensor data is sent over canbus. The plan is to send the sensor number and mac address the first time it is seen. Then just sensor number and pressure every time the sensor broadcasts data. Sensors only send data on average every 10 minutes or so. Unless they detect a leak over time or a rapid change. Once they stop they send a idle message and go to sleep about 15 minutes later.

Some aero updates from previous generations.

There have been a few places making complex gyroid mathematical shaped coolers (YouTube link) for a while. Now metal printers are cheap enough for intercoolers in more mass produced vehicles. Making water air intercoolers even more compact and efficient. YouTube: https://www.youtube.com/watch?v=1qifd3yn9S0 intercooler: https://www.confluxtechnology.com/product/gas-liquid-heat-exchangers/water-charge-air-cooler/

Still working on the web side of the TPMS as need to figure out how to run scan and get feedback as scanning is a heavy load and blocks the web server while running. Will likely add a scan time for user to set rather than 5 seconds. That way you can have a 5, 10, 20, 30 second option giving time to get the sensor to wake up and start broadcasting. Some you can just blow on, others need to be atmospheric then 20psi+ and last lot require a lot of movement. Movement ones can take the longest to wake up, eg put in a bag and spun around. Had to learn a bunch about Bluetooth packet headers to write a custom parser since the built in one decodes far more than needed for beacons like tire monitors. Another area I’ve been looking at, is aerodynamics which other than wool tufts needs measurement. I already have some aircraft vortex generators fitted. Anything aerodynamics related costs way too much money or have very limited use. Making 8 channel sensor set doesn’t look expensive compared to to the 1-10k price for an off the shelf device. Sensors can be a mix of single point measurement or dual point(differential) ones, eg single measures absolute pressure and differential you place a tubes from the sensor to top and bottom of wing and it measure the difference.

Added rubber seals to doors. Both the outer gap between front door and fender, and between front and rear doors. Between the door one just pushes on to the rear door lip. The front one is a pain with limited space and hinges in the way. each type covers both sides and are usd$5-7.50 under aliexpress bundle deals. For bundle deals order 6 items each time to maximise the auto applied discount. front to fender is called Z seal. between doors https://www.aliexpress.com/item/1005011547474124.html have a rear door to body seal on order.

Tpms Bluetooth and canbus all tested ok. Can read any known sensor when given ID. Now need to write the web interface and scanning for new sensors IDs and detect the type. Will basically act as Bluetooth to canbus bridge. Sending sensor ID along with pressure and temperature when it comes in. TPMS also send alerts when pressure drops below 20psi which should be a unique message so ecu can trigger warning eg engine check light or dash message. A few more brands of sensor arrived finally. For some reason on got delayed and has been at airport for a week. The 3 types should cover a large selection of aliexpress ones. I have seen one 6 wheel set on there that look different that maybe different. The most common type that is documented everywhere is the same as the haltech ones. Since there is no standard for how to measure tire pressure from some sensor read 0 at sea level not 100kpa, 1bar, 14.5psi. below supported so far… can be mixed and matched as software doesn’t care what type is on which wheel. Sometimes aliexpress has cheap sets of 2 for bikes. The ones still at airport look the same as 2 below but are Bluetooth 5 not Bluetooth 4. My guess is they are exactly the same data just faster and lower power. 1) random cheap usd$15 ones I first ordered and decoded. Similar to most common but have different voltage calculations. 2) these are common format ones. Many have Leepee on them. They have a larger antenna around battery. 3) these were the second cheapest when on sale at usd$16. Only pressure decoded, not temperature data. In Bluetooth manufacturer data starting with AC00 Or 00AC depending on byte order ( ( byte2 | byte3 << 8 ) >> 3 ) * 0.1 = kpa, then add 100 if you don’t want to read 0kpa at sea level.

Sti hatch likely to be released based on last years mktor show demo and close to patients. BRZ to enter Japan rally this year in 4wd, no indication that there will ne road going version. But this is the second time that a factory 4wd drive BRZ has been made. on track from a couple of weeks ago.

Latest board for TPMS or any wifi and/or Bluetooth to canbus board arrived on Monday. Made the first one today and it seems ok so far. Needs testing for canbus side but I’ve tested previous boards with the same design so it should be ok. Have enough processors to make 9 as I think one maybe DoA. This board while for TPMS has 8 IO pins and power on a set of plugs. The same JST ones link have inside their ecus. So anyone can customise them and write their own code in arduino or similar. There is a listen only option and the canbus is powered off on boot just to be safe. One option is use the open source project for canbus sniffer over wifi. That way you can install it once and then use it whenever needed without tying up the diag OBDii port. A couple are being sent off to be Bluetooth to wifi bridges for home assistant. This is for a house but I know people have added a wifi bridge to their car so when it’s in the garage it reports voltages for battery and oil temps in snowy climates. Batteries can include EV charging if it have canbus. Works on 12 and should also work on 24v as input takes up to 30v and protection kick in just below 32v. Case is IP67 and antenna and wiring can be sealed up very well. One is a panel mount, the other is a pole (aka roll cage) mount. The board fits in either case. That about 8-10cm long and 5-7cm long with mounting tab. Antenna is just a standard SMA male like a home internet router so you can fit a big or small antenna depending on use case. Stubby ones are about 3cm, home router ones are 15-20cm. This was the first time trying a stencil for a pcb and it was far quicker. It’s like screen printing but with solder paste. Lay the stencil and wipe the paste over and it coats all the pads for the components. PCBway charges a lot for them but JLCpcb charges for size. I figured out that making the stencil smaller is not only cheaper but if it fits in the regular box doesn’t increase shipping. Small box is around 18x16cm once they add bubble wrap. Making it usd$7 at JLC vs usd$30 for PCBway just for stencil.

Subarus 2025 patent application japanese https://www.j-platpat.inpit.go.jp/c1801/DE/JP-2025-019542/30/ja English https://www.j-platpat.inpit.go.jp/d0200 is it possible the scoop is purely aero. As in the air goes in the scoop and exits across the whole windscreen? With a smaller slot to the engine bay so it create a vacuum. That would make it a front mount intercooler, low mount turbo and rotated intake manifold. Given the low mount front turbos seen on recent models it is possible.

Well shift lights just need assembling and will have 3 spare 40 led bars 20mm square by 22cm long I will make another few 16 bar smaller ones 12mm square by 15cm with a hide away box for the brains. I have 2 cases for the old school flashlight ones which I want to experiment with. There is also another dinosaur in bright lime green that could be used. I got 2 initially but they sent pale green knock off one instead of blue. The Bluetooth TPMS boards should arrive next week so I can make TPMS to can bus for logging. They should support most Bluetooth sensors so you can buy cheap ones and have multiple sets of wheels with sensors. It will log which ones it sees on startup. Since sensors sleep until moving it should only log the current wheels. The main audio project got a little larger than planned and now does a whole bunch of new things. Also adding language support so far English, but Spanish is a work in progress and Japanese should also be supported. Mostly that around how the say numbers. English has unique up to 20 eg we say eighteen not 10 and 8. Spanish is unique to 30, but has “y” between larger numbers which all needs to be coded. https://www.jaycar.co.nz/super-large-seven-segment-display/p/ZD1850 While waiting for parts YouTube recommended a few rally videos. One of which had a nice gear indicator mounted to the side of the dash cluster. So 40 hours later a 70mm tall (58mm for actual LEDs) 8 segment display for canbus is almost ready to order parts to see what actually fits. The controller with same wifi setup fits exactly behind the display and has M3 mounts inneach corner. Just thinking about adding a few solder points for a light sensor for night dimming incase the car doesn’t have canbus. You can make it show 1-10 by setting ecu to sending it a can message or a byte where each of the 8 bits turns on a single led segment. Will add option to read clutch over canbus to show C when it detects clutch rather than last gear position.

after looking at aerodynamics videos and Subaru related content the algorithm surfaced this. Its English overdubbed which can be a bit annoying when there are two people talk over each other. https://www.youtube.com/@stion-tube5753/videos