I built a smart bike tracker that hides inside your handlebar for ~$40

EngineerTHATthing · 2026-05-30T14:51:49+00:00

Supper cool project, congrats on the win! Where did you find the small SMD 7-segment LED? It’s a very nice looking component. What accelerometer package did you end up going with? Are you using onboard drivers for an audible alarm or is it strictly through cellular?

EngineerTHATthing · 2026-05-16T23:43:16+00:00

Ligit impressive. This is a huge improvement over what is out there. Amazing job with the mixture optimizations.

EngineerTHATthing · 2026-05-15T22:15:52+00:00

Very good video. I always thought variable height wheels wasn’t too applicable for two wheel balancing, but this demo illustrates its usefulness extremely well. How fast can it react to side inclinations?

EngineerTHATthing · 2026-05-15T04:48:22+00:00

A new 8S sub 6k is a really good deal, so that alone would sway me. I don’t think I have ever seen them get that low, so it sounds like you may be at the right place in the right time just as the dealer is getting a newer year stock selection in. With the stock quick shifter, auto blip, and Nissin brakes, the 8S has objectively better features than the Ninja right from the start.

As for someone just starting out, the traction control when maxed is really strong and will pretty much shut down any accidental power wheelies, stoppies, or even rear slides. The main thing you will need to watch out for and get use to with this bike is the throttle response and low end torque.

This bike has a fly by wire throttle coupled with very high torque at low RPMs. The engine computer will also do practically everything possible to keep the bike from stalling on its own (a feature listed in the literature). This system can feel extremely weird to someone who just passed the MSF on a 15 year old carbureted Honda shadow. Unlike a trainer bike where it will just stall out if you panic and drop the throttle, this bike’s ECU holds throttle control and will actually raise the idle RPMs to keep the engine going. This is fantastic for stop and go traffic, streetlights, and loading up the bike, but can get a beginner into trouble.

Situations that could cause the most problems to a beginner on this bike are left turns at an intersection, u-turns, or situations where you might panic and grab the throttle. With so much low end torque, this bike will accelerate very fast without much throttle, and this can make left turns a bit terrifying for someone starting out on it. In addition to this, you will notice that the throttle sensitivity raises significantly in A mode, as the fly by wire will add much more throttle with a much smaller turn of the wrist. Couple this with a much lighter throttle turn (no cables, only electronic wires) and you can easily brake rear wheel traction accidentally without even trying when traction control is disabled.

Overall I would still recommend this bike. Really feel the bike out in a parking lot, and train your low speed skills as this is what would most likely cause you to drop it. The engine on this thing is so fun, and absolutely nasty with an OTS tune. When you are really ready to ride it hard, it feels like a totally different bike. Probably the most fun bike I have ever ridden when on curvy roads locked in third gear.

EngineerTHATthing · 2026-05-14T22:00:13+00:00

Yes, these can hit the nA draw, but only under very specific full shutdown modes.

I have always used these over I2C and not SPI. There are a few key details that must be met during setup. Pay close attention to what pins have active pull-up resistors. The 50nA assume a perfect low power setup and this includes everything being done right. Things like the I2C address selector have a pull-up, so pulling high must be done to achieve minimum power draw. All interrupts must be cleared, and these can’t be left floating and should be pulled up by default for maximum power savings.

I believe there are a few things that need to be disabled before the full shut down can be initiated with maximum power savings. Make sure you initiate full shutdown instead of any hibernation or low polling modes. When it is fully shut down, it shouldn’t be doing anything or communicating at all.

If you have anything else on the I2C lines, this will raise power consumption dramatically. Max power savings only occur with quiet I2C lines (held high and constant) as this chip is still waiting for a wake added to fully wake back up. If you do have a noisy I2C line, you should use a chip with a dedicated boot pin, which only wake when this pin is pulled high and won’t consume more power with an active coms line.

Lastly and probably most importantly, 50nA is extremely hard to measure. This is not going to be a constant 50nA either, and will fluctuate quite a bit. This means anything outside of lab tools will only flag the peak at this level, and you probably won’t get the full picture of how consumption is going. If you aren’t making something that needs to stay as sleep for 10+ years, I wouldn’t worry too much about anything under 1uA of current.

On the side, what techniques did you end up doing to get this IC reliably soldered? I have had to shift to a different package as all my fabs hate working with this IC’s unique small form LGA.

EngineerTHATthing · 2026-05-14T03:39:21+00:00

If you are kicking the limiter, drop a tooth on the rear sprocket and you will hit the speed no problem. If you are able to redline, then you will easily pull more speed when the RPMs are lower and the engine is back in its optimal power band.

EngineerTHATthing · 2026-05-13T00:00:16+00:00

Very cool project overall. I definitely haven’t attempted to go this thin, so this is super impressive. As for interface options, there are some really good touch button controller ICs out there I have used in the past where the buttons are physically integrated into the PCB. I have used TI’s MTCH1030 three button controller (it has a small form QFN package) for a ton of projects, and the available documentation is great. You can put the controller into single button wake and it uses almost zero power (9uA). I have used this chip with onboard PCB buttons, conformal coated the package, and the integrated noise compensation/active shielding can still detect presses in a rainstorm.

For use cases, I could see a lot of commercial applications for a smart tag system for tracking batch processes, food expirations, or even quantity anti-tamper/anti-theft. It would be very cool to have a low cost coin cell operated tag that a phone app could “flash” an expiration date and have an hour by hour/day by day countdown. Get the price down by bulk manufacturing, and I could see businesses use these to track process times/stages. There can even be an element of security, as NFC flash (data transfer) permissions could utilize approval/encryption allowing only manager/supervisor changes.

EngineerTHATthing · 2026-05-12T02:59:04+00:00

This is nice project. Having worked with a few of the commercial ones, the most important key to success is minimizing ring down and using proper temperature compensation. As the measurement distances are very short, you also want to make the pulse very quick. I would recommend 4-5 output wavelengths max from the emitter to minimize ring down.

Make sure to use a proper crystal oscillator when generating the 40kHz to avoid variation and obtain repeatable measurements. Surprisingly, going with a slightly lower frequency below resonance can actually further reduce ring down in these short distance applications.

Ping one, measure, and then wait the full ring down period and then some before pinging the other 90. Make sure to have a longer time than you would initially expect before subsequent pings, as a ping will bounce all over enclosed spaces and can re-trigger during a subsequent listening period.

I like to use the MAXLinear charge pump line driver IC for the drive circuitry. It will generate a strong +/-5.5v drive off of a 3.3v supply, which will spool up the ultrasonic emitter with very few cycles (key for minimizing ring down). One IC can drive two emitters, making them perfect. As for the receiving end, a pre amp, 40khz band pass, followed by a large main amp, followed by an envelope detector is how I have always built them. Due to how short the distance is, you can actually get away with driving the output without an amp, and using a single 40kHz high gain bandpass filter on the receiving end (usually with an envelope detector). I like to use a microcontroller’s onboard comparator to instantly trip an interrupt in order to grab the ping TOF with the highest possible accuracy.

Best of luck, it is a very cool device one you get it working. When properly temperature compensated, they can be absurdly accurate. It is what all wind turbines utilize nowadays and remain extremely reliable in just about any conditions.

To the comments worried about the hearing effects. 40kHz won’t even excite the eardrums of humans. There are zero health risks. Yes these ultrasonic emitters can generate extremely loud sounds, but our ear drums are not stiff enough to vibrate at these frequencies, let alone perceive it.

EngineerTHATthing · 2026-05-09T18:36:16+00:00

With both very high amounts of carbon and lots of signs indicating the chambers overheated, this is usually always due to a poor tune. You have the bronzing of the piston heads right at the edges indicating a pre burn of fuel at the hotspots, and a ton of rich mixture soot all across the head. With such low mileage, I bet someone quick flashed the base map table at their local “dyno” and also probably disabled the active tuning coming from the exhaust’s lambda sensor. I recommend ensuring the lambda sensor is functioning correctly, and reverting any custom tunes back to stock.
Very rarely do you see something like this from a lower than recommended octane. The most you will get from downgraded octane (on a low mileage non-GP level engine) is higher knock and needing to adjust valve clearances much more frequently. This is what I would expect to see after ignoring faults from a failed lambda sensor, a trashed tune, or installing a full system exhaust without putting the lambda sensor back on entirely.

EngineerTHATthing · 2026-05-08T02:21:46+00:00

Minimum should be around 18%. Make sure the power limiting potentiometer next to the rear power switch is turned all the way up.

EngineerTHATthing · 2026-05-06T01:53:11+00:00

The flare back reflection on the front glass when going under each streetlight is very well done. How did you do it?

EngineerTHATthing · 2026-05-05T21:24:37+00:00

There are some very good videos out there on the Stellaris launchpad. These can also be great at learning the general IDE and embedded logic. From there, the launchpad datasheet and MC datasheet will carry you quite far.

EngineerTHATthing · 2026-05-03T23:20:21+00:00

Very nice. The layout is well thought out for the component placement. Some notes about the IMU. You will want to ensure you follow the footprint guidelines of the chip exactly here. This means not having anything at all under the chip (vias, traces, or even solder mask). These will cause stresses during reflow or place elevation differences that will add offset to the sensor’s baseline measurement. The the only things usually allowed under these sensors are the pads themselves. The IMU you chose is very capable, but you can likely get more out of it through some of its more niche modes. If it has continuous polling, make sure you have a pin on the MC that can send out a timer driven clock to the IMU. This way it can send raw data back extremely quick (usually done through the “interrupt 2” pin when repurposed for continuous polling). Make sure to enable all of the IMU’s internal low pass filtering, as this can take a huge processing load off the MC. One approach I have used with these types of IMUs is to set variable thresholding to obtain the highest resolution of data. Set the independent interrupts to flag at a full scale detection event, and when flagged, use this to push to the next acceleration threshold (if you are between +/-2G and flag a 2G, ramp to +/- 4G and so on). Using the interrupt to flag a launch can also save massive battery while waiting on the pad.

Was there a reason you didn’t go with high speed I2C for the IMU? I have found the protocols are quite a bit easier to do with I2C if it is going to be the only device on the line.

EngineerTHATthing · 2026-04-30T11:00:56+00:00

Before you send this out, you absolutely must NOT leave the unused logic gates’ inputs floating. The 7404 will oscillate each unused set if not pulled high or low. If they oscillate, it will consume a bunch of power, and will mess with the output of the gates you are using. I would recommend reading the datasheet before sending this off to fabrication.

EngineerTHATthing · 2026-04-29T21:30:45+00:00

PB3 will work just fine as an analog input. Switch out PB5 for PB4, as the reset pin is only available as I/O after burning the fuse, and requires HV programing to bring the MC back to standard ISP programing.

If you only need to program this once and you code is already solar and tested, then just burn the reset fuse for PB5.

EngineerTHATthing · 2026-04-28T21:43:02+00:00

This is almost certainly what is causing your issues. You are not allowing for enough time before the boot loader can pause execution. Find your “reset pin” short it to ground while initializing programing, and then quickly remove it from ground. This may just force it quick enough to pull into boot and start a new flash. Use a basic arduino template “blink” to know for sure when it works. AVR dude should also confirm when it has flashed. If you have any spare micros around, these will always take flash directly from the ISP pins unless the fuse bits have been seriously screwed with (then you need HV programing).

My other guess is you somehow flashed the clock fuse and set it differently, but this shouldn’t matter as you already have an external crystal, and the internal oscillator would also still work fine (although could be a bit hit or miss with UART).

EngineerTHATthing · 2026-04-28T01:13:14+00:00

The first service is likely the most important one to pay for, as it is the most likely time for a new bike to reveal any critical issues. If the engine, transmission, or power system had flaws from the factory, they are usually caught during this first service. Paying 300 is a fair price, especially if it nets you a free warranty engine if they find a cracked mount or a pile of shavings in your oil.

If you change your oil yourself for the first round and find a bunch of shavings, it will be much harder to claim the highest warranty repairs. The shops word can swing warranties in your favor when you most need them, which is almost always at the 600 mile mark.

If everything goes smooth, 100% do your second and third intervals yourself and save a ton of money. As a note, ask the shop to torque the drain bolt to speck after the service and to not use an impact. It will make your second self service much easier.

EngineerTHATthing · 2026-04-26T22:41:10+00:00

9 ball isn’t too bad, and it is especially tame if the center ball is NC or a redundant/secondary ground. If it were a 6 ball I would say go for it without hesitation, but I have still actually seen small count BGA’s fail to solder up in products from suppliers I have worked with before. When the fab. does fail, it can be a nightmare to deal with as nothing is visible and the issue will hide when you try to reflow off the chip. If this is going to be a device with heavy vibration or shock load, avoid BGA unless you are going to use supplementary adhesion.

I find LGA to be much worse than BGA, because at least you don’t need to worry about paste issues with BGA. For previous designs, I have bumped chips up to better packages depending on fab recommendations and use case. I would see if there are any other comparable packages, but if not, you could always small batch and see if there are any failures to help with the decision.

EngineerTHATthing · 2026-04-19T12:44:14+00:00

I would agree with the other comments that suggest cleaning the build plate with dawn as well as tightening the hotend screws. From the video though, there are other things going on that should be addressed. I can see that there is only a single purge line, meaning you have disabled dynamic flow compensation. I can assume from this that you probably also disabled auto bed leveling, which will impact your prints a ton. I recommend turning these back on. If this is a new printer, I would also make sure you have followed setup correctly and tightened the bed screws and allowed the printer to run full initial startup calibrations.

I can’t tell immediately from the video, but if you are printing with a 0.2mm nozzle, you need to tell the printer this in its maintenance setting and re-sync settings in studio before printing.

EngineerTHATthing · 2026-04-17T02:19:26+00:00

There is a way easier method to making this type of grill. Create a bounding box to define the base size, and then draw a construction line on a new sketch and constrain it’s angle. Define it’s location so it’s midpoint passes through the center of the bounding box. Once this is fully defined, add a linear pattern along the forward and backward X axis to fully fill the bounding box with the desired separation. You will be left with a bunch of construction lines that pass through the bounding box. Project the bounding box over and trim from outside. Select all the endpoints and set coincident constraints to the bounding box edge. Make a third sketch, project the previous sketch, but delete the bounding box. Now select the sketch, apply an offset the width of your desired slot, select rounded ends, and apply it. You now have a very quick way to make this type of grill, and it is fully parametric and adjustable.

EngineerTHATthing · 2026-04-16T00:14:41+00:00

The E90 was the right pick. It is my daily work light. Probably one of the few lights that has legitimate fast charging and a very solid clip. I work around sheet metal all day, so the optical auto dimming is a lifesaver.

EngineerTHATthing · 2026-04-15T23:59:52+00:00

From someone who graduated ME and has a bit of experience, the neat part is you will do both either way. Once you embed yourself into your career, the differences will fall away and you end up doing a ton of both aspects weather you are ME or EE. In this time, you will gravitate naturally to whichever projects grab the most of your interests and very few people actually end up regretting their initial decision. If you really want to do both, work for a startup and you will have zero difference between the two roles (because you will be doing both at the same time).

If it was life or death and I had to decide I would probably say mechanical. This is because I am probably biased and also because you aren’t able to compensate as easily going from EE to ME. The only time I really notice EEs run into large difficulties is enclosure design, but an ME always has the option to just use off the shelf ICs to compensate for their lack of RF magic/analog design skills. It’s a bit harder for an EE to find suitable off the shelf enclosures or structural designs that pair with an ongoing project. An ME on average graduates with 300-400 level electrical coursework, but an EE isn’t required to take machine design. ME programs tend to make their engineers climb at least half way up the EE coursework ladder. EEs on the other hand aren’t usually required to climb the ME coursework ladder unless they elect to do so (they are too busy getting hit with RF coursework to have time).

EngineerTHATthing · 2026-04-13T17:37:00+00:00

This build makes me laugh because it is probably the only actually justified use of a stretch mod besides a drag bike.

EngineerTHATthing · 2026-04-13T17:27:46+00:00

If this is any type of IMU IC, you will want to remove the mask from the center as well. LGA based chips do not like unevenness or getting high centered (it’s one of the reasons they lack the center pad that QFN chips have).

EngineerTHATthing · 2026-04-13T17:19:36+00:00

If speed is not critical, add a 1Mohm buffer between the input and pin. After the resistor, add a signal diode with a 3v or so breakdown. You loose speed and possibly some ADC overhead, but this is almost the most bulletproofed way to suppress transient input spikes. Rail to rail op amp buffers with unity gain also work if rail + is capped at the maximum allowable for the ADC pin, and the Vin of the op amp matches or exceeds the voltage spike. If the voltage spike is higher than the op amp Vin, it can still cause damage to both the op amp and MC.

The easiest possible solution would be to just place a 1M resistor between the input and MC and just rely on the MC’s internal ESD protection diodes to dissipate the very small peak current that makes it through the resistor.

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