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Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Electronics Workbench

Electrical & Electronic gadgets

  • Nuheara IQbuds² MAX: User Notes

    Nuheara IQbuds² MAX: User Notes

    A friend with declining hearing asked for my experiences with the Nuheara IQbuds² MAX I’ve been re-batterying for quite some years:

    Nuheara IQBudsMax2 - battery replacement
    Nuheara IQBudsMax2 – battery replacement

    Given that other folks may have the same issue, herewith a lightly edited version of the email I sent:

    Do you use conventional hearing aids?

    Nope, because when I was looking around, maybe six years ago, dropping $500 on Nuheara rather than $5000 on real hearing aids seemed like a good first step. Five Benjamins would be lost in the roundoff should I get something seriously exceedingly much more definitely better.

    They are now $200 from Amazon. Nuheara had licensed the design to HP and stopped selling them in the US, which is what you’ll find on their website, so maybe the Amazon seller isn’t entirely legit.

    My decision was partially based on an audiologist measuring my ears and stating my loss was “not aidable”, which meant it wasn’t severe enough to justify hearing aids. I interpreted that to mean her experience with similar folks showed insufficient return for the sales effort involved.

    Before OTC hearing aids were legit, Nuheara was rated very near the top of the “not really hearing a hearing aid” pack. The better ones cost about half the price of real hearing aids, so IMO it was the best cost-performer.

    Every time the question has come up since then, the crux is “Would real hearing aids be that much better than the Nuheara buds” and the answer has been “Nope”.

    I’ve done occasional test sessions with various “hearing instrument specialists” and the results show I have essentially no hearing above 1 kHz, thus reducing female voices to mumbles. They are unwilling to test my hearing while wearing the Nuheara buds, for obvious reasons.

    Do you use Nuheara instead?

    Pretty much whenever Mary is around, because that’s the only way I’ll understand what she’s saying unless we’re face-to-face in the same room.

    The noise reduction (see below) works wonderfully well in the car, eliminating all the road noise and isolating her voice.

    experience and any advice

    Unlike simple “personal sound amplifiers”, Nuheara has a six-band equalizer with settings based on an automated “Tap when you hear the tone” test done in the app. It does not, much to my frustration, display a line graph or export the numbers, but the circular diagram shows I don’t have much hearing above the lowest two channels:

    Nuheara Ear ID - 2026-0811
    Nuheara Ear ID – 2026-0811

    I think the lower quarter of each side the rings is cosmetic filler, given the silence I hear when the test is surely presenting the higher frequency tones. If there’s a lower score than what I get, I cannot imagine what it might be for.

    The buds have a high/low cut filter to reduce background sounds that works wonderfully on the ubiquitous 120 Hz hum anywhere in North America. I obviously don’t have much use for the high-cut filter setting.

    The “Speech in Noise Control” applies DSP magic to reduce general background sound and emphasize speech, which is more complex than a simple frequency filter: SINC is astonishingly effective. What comes through the DSP magic isn’t audiophile quality, but it’s comprehensible and that’s what counts.

    The downside: I hear nothing other than speech while it’s engaged. When we have supper on the screened porch, there is no background sound other than occasional traffic until I disable the filter and SINC, whereupon I can hear the breeze rustle the leaves / birds chirping / Vassar carillon chimes / stuff like that. Fair tradeoff, IMO.

    The DSP monitors ambient sound and adjusts the overall gain to reduce the in-ear volume. My normal settings turn the water stream from the kitchen faucet into deafening white noise, but the gain drops after a few seconds and I’m effectively deaf. This also applies when we’re walking outdoors, with any wind noise in the microphones turning the gain down enough that I hear just as poorly with the buds as I do without them.

    The buds can stream audio from the phone and the equalizer applies to phone calls / music / whatever. Real hearing aids tend to not stream audio, because Bluetooth requires bigger batteries. Getting phone calls with adjusted audio in both ears is wonderful.

    The buds also have “tap” controls to start / stop streaming, raise / lower volume, and (most importantly) enable / disable “world audio” = I can mute the sound before I start doing something noisy. The “world off” = active noise cancellation isn’t perfect, but it’s Good Enough for most purposes.

    I wear them under Peltor 28 dB hearing protectors (which cost 25 bucks two years ago sold by Amazon, so beware scalpers) while mowing: the muffs knock down all sounds and the buds remove what’s left. I can then stream music at reasonable volume to make mowing easier.

    Those big batteries make the buds heavy in the ear, but it seems the same batteries appear in audio-only buds, so they may be the smallest ones that get the job done.

    A good ear canal seal is essential and I’ve gone through several different “brands” on Amazon before finding effective foam tips.

    Bottom line: I have no experience with their competition, but the Nuheara buds do everything I have ever read other buds / real hearing aids can do. Color me satisfied.

  • Nuheara IQbuds² MAX Battery Replacement: Round 3

    Nuheara IQbuds² MAX Battery Replacement: Round 3

    The OEM lithium batteries in my Nuheara IQbuds² MAX not-really-hearing-aids lasted for about 2-½ years before needing replacement. Two more years pretty well did those in and I replaced them again without fanfare about a year ago.

    After replacing the 802050 pouch battery in the charging case and having discovered two spare LIR1654 batteries at the back of a workbench, I installed those and renewed the gaffer tape holding the earbuds together:

    Nuheara IQBudsMax2 - battery replacement
    Nuheara IQBudsMax2 – battery replacement

    The workbench stash also disgorged the old Varta LIR1654 batteries, but not the OEM ones, so a test session seemed in order:

    Lithium LIR1654
    Lithium LIR1654

    The Varta batteries (red and blue traces) are in sad shape, after two years of regular use and another three years idling in a small bag. The EEMB batteries (pink and cyan traces) are in better shape, despite their year of use, with the lower pair of traces showing their as-extracted charge and the upper three traces their just-charged capacity.

    They’re still doing better than their 0.4 W·hr nominal capacity, which is not to be sniffed at, particularly as the tester’s minimum 150 mA current presents a rather stiff load for a 100-ish mA·hr cell.

    This being a quick-n-dirty set of tests, a simple discharging “fixture” sufficed:

    LIR1654 battery discharge clamp
    LIR1654 battery discharge clamp

    The charging “fixture” wasn’t much fancier:

    LIR1654 battery charge clamp
    LIR1654 battery charge clamp

    The EEMB batteries are in the bag and may remain in good shape after two more years, ready for another tour in the earbuds when their relatives wear out.

  • Tour Easy: E-Bike Brake Sensor Installation

    Tour Easy: E-Bike Brake Sensor Installation

    Having verified the brake sensors work and with some idea of their actuation distances, installing them on Mary’s Tour Easy involved no more than:

    • Remove the fairing
    • Unwrap three spiral looms from All The Cables
    • Wrestle the Julet connectors apart
    • Plug in the new sensors
    • Stick the sensors in the proper locations
    • Verify proper brake operation
    • Rewrap the looms
    • Install the fairing

    The “proper location” put the actuation point about halfway between the brake lever’s released and pulled positions. Given that the previous sensors lacked indicators, I don’t know where their actuation point might have been, other than likely too close to their released position.

    A slideshow of the front brake lever positions:

    • Tour Easy LED brake sensor - front released
    • Tour Easy LED brake sensor - front activated
    • Tour Easy LED brake sensor - front pulled

    Similarly for the rear brake lever positions:

    • Tour Easy LED brake sensor - rear released
    • Tour Easy LED brake sensor - rear activated
    • Tour Easy LED brake sensor - rear pulled

    Obviously, the rear brake lever sensor has the “dim” LEDs.

    There’s not much to go wrong and the first ride was uneventful, so we’ll declare victory until the sensors or magnets shift their position, despite the wraps holding their wires to the brake cables.

    The magnets come from power toothbrush heads, encased in urethane adhesive in 3D printed mounts.

    Stipulated: I sometimes over-do things.

    However, I am absolutely not going to back down from saying the lashup shown in this screen grab from the sensor installation video is utterly and completely wrong:

    E-bike Brake Sensor - suggested installation
    E-bike Brake Sensor – suggested installation

    Do not get me started, you know how I am. OK?

  • E-Bike Brake Sensor Bench Check

    E-Bike Brake Sensor Bench Check

    A pair of brake sensors with LED indicators arrived and should improve the situation on Mary’s bike.

    The connector pinout, as seen looking into the jack on the controller side of the cable:

    Bafang Brake Sensor pinout
    Bafang Brake Sensor pinout

    Of course, one cannot depend on color codes, but now we know it uses a 5 V supply. Some rummaging produced a suitable (“Julet”) connector, a cutoff USB cable, and a USB power supply:

    Tour Easy LED brake sensor - bench test harness
    Tour Easy LED brake sensor – bench test harness

    You’ll note the sensor’s signal wire is blue, not white, but red = 5 VDC and black = common on both sides of the splice. This is not to be sniffed at.

    With the disk magnet (supplied with the sensors) oriented edgewise to the sensor, so the magnetic field is largely cancelled, the maximum separation allowing the sensor to remain On is about 7 mm:

    Tour Easy LED brake sensor - edge - max ON
    Tour Easy LED brake sensor – edge – max ON

    The minimum distance allowing it to be Off is 8 mm:

    Tour Easy LED brake sensor - edge - min OFF
    Tour Easy LED brake sensor – edge – min OFF

    Orienting the disk face-on to the sensor increases the distances, because the magnetic field is not cancelled out in that direction. Similarly, positioning the magnet either above or below the plane of the sensor changes the results.

    The maximum On distance is now 20 mm:

    Tour Easy LED brake sensor - side - max ON
    Tour Easy LED brake sensor – side – max ON

    The minimum Off distance is 22 mm:

    Tour Easy LED brake sensor - side - min OFF
    Tour Easy LED brake sensor – side – min OFF

    The other magnet has a similar field strength and the other sensor responds at nearly the same distances, so they’re reasonably matched.

    The LEDs are, however, not well matched: one sensor is much brighter than the other. I only have one connector, so I cannot show both in the same picture. These pictures have the same exposure (1/120 s and f/1.7), with the top sensor appearing in the previous pictures:

    E-bike Brake Sensors - LED Brightness comparison
    E-bike Brake Sensors – LED Brightness comparison

    The red LEDs show a similar difference. I’m certain this doesn’t rise to the level of a warranty claim, because, hey, maybe the brighter one should be dimmer.

    Now, to fit them on Mary’s bike …

  • Bafang Brake Sensor Magnet Re-Re-Realignment

    Bafang Brake Sensor Magnet Re-Re-Realignment

    Several years and realignments later, the brake sensors on Mary’s Tour Easy became slightly mobile on the foam tape holding them to the brake lever mounts and, of course, anything affecting the sensor position relative to the magnet inevitably makes it overly sensitive to the brake lever position.

    For unknown reasons, the DPC-18 displays devote zero pixels to the brake sensor status, so the only indication of a brake sensor being active is when the motor cuts out. This is not to be tolerated, particularly in traffic, so both the sensors and their magnets are now remounted on fresh tape with careful attention to proximity.

    The magnet is snugged against the sensor when the lever is released:

    Tour Easy brake sensor gap - released
    Tour Easy brake sensor gap – released

    The activation point is about a third of the way to the fully pulled position:

    Tour Easy brake sensor gap - braking
    Tour Easy brake sensor gap – braking

    I would prefer having the magnet move parallel to the sensor’s long axis, but that’s just not the way these levers work.

    The left-side sensor cable is now snugged to the brake cables to keep it out of harm’s way as she installs & removes the water reservoir on the handlebars under the fairing:

    Tour Easy brake sensor cable - left
    Tour Easy brake sensor cable – left

    For symmetry, the right-side sensor cable sports a similar tiedown:

    Tour Easy brake sensor cable - right
    Tour Easy brake sensor cable – right

    Having recently discovered brake sensors with integral LED status indicators, I plan to update that whole mess in the near future.

  • Water Heater Anode Rod Replacement

    Water Heater Anode Rod Replacement

    The Bradford White AeroTherm heat pump water heater that Came With The House™ has been running for three years. Based on previous experience with the same City of Poughkeepsie water, it was time for a look at the anode rod.

    Which, as always, required the Greatest Ratchet with a foot of extensions getting the 1-1/16 inch socket down to the rod:

    Water Heater Powered Anode - socket wrench
    Water Heater Powered Anode – socket wrench

    Remember to:

    • Turn off the water heater power
    • Shut off the inlet and outlet valves
    • Open the drain valve to relieve the tank pressure
    • Only then loosen the anode rod

    Seeing the first few inches justified extracting the rod:

    Water Heater Powered Anode - old rod top
    Water Heater Powered Anode – old rod top

    Due to low overhead clearance and inauspicious pipe locations, I had to hacksaw the bottom third off to extract the rod:

    Water Heater Powered Anode - old rod overview
    Water Heater Powered Anode – old rod overview

    Water Heater Powered Anode - old rod bottom
    Water Heater Powered Anode – old rod bottom

    With the rod out, draining a few gallons of water into a pan didn’t produce any notable gravel, so I didn’t do a complete flush. Much to my delight, the drain has a ball valve!

    Given that this is a fancy water heater and I no longer regard anode rod maintenance as a fun-filled activity, I installed a Corro-Protec powered anode rod for cathodic protection without all the crud:

    Water Heater Powered Anode - Corro-Protec parts
    Water Heater Powered Anode – Corro-Protec parts

    The wall wart proclaims 15 mA with a green LED indicating it’s hard at work:

    Water Heater Powered Anode - Corro-Protec wall wart
    Water Heater Powered Anode – Corro-Protec wall wart

    The data plate on the back reports 24VDC 15mA, but, being me, I poked at it with a handful of resistors:

    Corro-Protec power supply measurements
    Corro-Protec power supply measurements

    The electronics could be as simple as a 24 VDC wall wart feeding a 425 Ω series resistor and a transistor switch lighting the LED for currents a little over 6 mA.

    A quick ohmmeter check shows the powered rod electrode is open-circuit with respect to the tank, as it should be without much applied voltage. Applying +24 VDC from the wall wart drives 15 mA into the water: the rod is hard at work.

    I’ll take a look at it in a year or so just to see what’s going on in there …

  • Nuheara IQbuds² MAX Charging Case Battery Replacement

    Nuheara IQbuds² MAX Charging Case Battery Replacement

    After five years of daily use, the lithium battery in the charging case of my Nuheara IQbuds² MAX they’re-not-hearing-aids earbuds began absorbing far more energy during its overnight recharges than the usual 100-ish mA·hr. This isn’t unexpected and, of course, Nuheara specifically mentions their batteries are not replaceable, so just toss the earbuds in the e-waste stream and buy another set.

    Having already replaced the smaller and harder-working lithium batteries in the earbuds twice, that’s just useless information … and something of a challenge.

    So, we begin.

    The lower part of the hinged case holds all the good stuff, with that blank hump obviously covering a great place for a battery:

    Nuheara IQBudsMax2 charging case - overview
    Nuheara IQBudsMax2 charging case – overview

    The bands around the earbuds are strips of gaffer tape holding their halves together after replacing their batteries. In this application, gaffer tape works much better than duct tape.

    There being no obvious screws, wedging a thumbnail into the joint just above the Micro-B USB jack proved promising. Doing the same on the other side produced enough of a gap to force a flat steel blade in there; further prying popped the snaps (red):

    Nuheara IQBudsMax2 charging case - snaps and glues
    Nuheara IQBudsMax2 charging case – snaps and glues

    The green ovals mark places where the case halves were glued together, accounting for some of the struggle.

    The two neodymium magnets in the front corners grab similar magnets in the upper cover to hold the case closed. The two magnets along the front edge grab magnets in the earbuds to hold them in the pockets, with more magnets flanking the gold-ish pogo pins visible in the first picture for better connections. If you’re concerned about the health effects of static magnetic fields, get over it.

    The battery was glued in place, so the first position after cracking the case apart must look like this:

    Nuheara IQBudsMax2 charging case - pried open
    Nuheara IQBudsMax2 charging case – pried open

    Yes. Yes, that is five years of earwax. You’ll note the lack of a seal at the bottom of the tunnels guiding the foam earbud tips: any and all particles falling off the earbuds have a direct path to the interior of the case.

    Easing the battery from its restraints reveals the data plate:

    Nuheara IQBudsMax2 charging case - snap and glue locationsNuheara IQBudsMax2 charging case - 802050 lithium cell
    Nuheara IQBudsMax2 charging case – snap and glue locationsNuheara IQBudsMax2 charging case – 802050 lithium cell

    The reflections in the pouch’s now-curved upper surface show the battery has become a Spicy Pillow.

    Somewhat to my surprise, 802050 batteries are available from the usual sources.

    Unwrapping several layers of kapton tape exposed the battery protection PCB:

    Nuheara IQBudsMax2 charging case - battery management PCB
    Nuheara IQBudsMax2 charging case – battery management PCB

    Comfortingly, the DW01 topmark on the upper IC says it’s a battery protection IC and the 8205A topmark on the lower IC indicates a dual MOSFET switching the battery current off during shutdowns. I did not trace the circuitry, but the white wire might control the DW01 CS terminal.

    The solder side:

    Nuheara IQBudsMax2 charging case - BMS solder joints
    Nuheara IQBudsMax2 charging case – BMS solder joints

    The new battery had a similar protection PCB with two wires. Rather than argue the point, I snipped its (welded!) battery tabs and transplanted the Nuheara PCB to the new battery, adding 30 AWG jumpers because the new tabs were shorter than the old ones:

    Nuheara IQBudsMax2 charging case - new battery installed
    Nuheara IQBudsMax2 charging case – new battery installed

    The strangely empty space to the right of the battery is just big enough for the protection PCB and all the kapton wrappings. The various plastic tabs around the battery hold it in place, so I did not renew its glue.

    Similarly, the four case snaps do a great job of holding the halves together, so they’re not glued, either.

    An overnight charge brought the case back to life and it’s once again working fine. However, the earbuds may be due for their third battery refresh.

    I love a happy ending!