Remote controls - IR or RF? - Page 1
Forum section: electronics / projects

author: daxliniere
author_rank: Regular Contributor
timestamp: March 09, 2025, 11:42:16 pm
content: Hey everyone,I was hoping to get some sage wisdom from any designers who have experiences using IR and RF remote controls in their projects and the problems they encountered.I'm working on a project that is based around an Arduino and bunch of relays. It switches audio frequency signals to different places and I have recently added an IR remote control function via VS1838B (IR receiver) and one of those cheap IR remotes you get with RGB LED controllers (CR2025 battery).It's all working, but I recently discovered that if the environment is bright (i.e. sunlight), it doesn't work reliably. This means I need to consider improvements to the system. The device is not safety critical, but I really don't want it to have a known point of failure.1) An IR filter (additional to the body of the IR transistor) - costly for the project and increases assembly complexity.2) Do I just need a better quality remote control?3) RF remote control (433MHz) is another possibility, but adds complexity (separate receiver PCB vs a single IR receiver transistor), more expensive (see previous), could be mistriggered by unwanted devices from another room, and also introduces RF noise in an AF environment (problem??)If anyone has any questions for me, please fire away.All the best,Dax.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 10, 2025, 01:27:26 am
content: Can you fit a shade to block direct sunlight getting to the sensor?

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: March 10, 2025, 04:24:45 am
content: Quote from: daxliniere on March 09, 2025, 11:42:16 pmThis is most likely the easiest solution. I've had remotes that can bounce off walls and the ceiling and still work. Some basic shading from direct sunlight and a more powerful remote control and it'll work fine.

author: ftg
author_rank: Frequent Contributor
timestamp: March 10, 2025, 09:07:23 am
content: I would advice against adding RF transceivers to the project unless absolutely necessary.And unless the radios are on 2.4GHz, you'll get to make multiple country variants due to differing regulations.Not having intentional radiators makes life easier.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 10, 2025, 09:22:52 am
content: Infrared is a better choice from many aspects, including price. Search for RC5 protocol, one of the most widespread.Typical receiver is aTSOP1738(or similar 3 pin IR receiver used in TV, set-top-boxes and alike), has all inside, it can be read directly with an Arduino, there are many ready made IR decoding libraries.Typical transmitter is an IR LED and a resistor tied to an Arduino pin. There are already Arduino libraries for transmitting IR codes. Eventually, you can also use almost any TV remote control, or other IR remotes from retired household devices.

author: akasaka
author_rank: Regular Contributor
timestamp: March 10, 2025, 02:49:31 pm
content: Be wary also that the VS1838B has a reputation of being very frequently knocked off, with the clones being shite enough to warrant an FAQ entry in some beginners' arduino libraries:https://github.com/crankyoldgit/IRremoteESP8266/wiki/Frequently-Asked-Questions#user-content-Help_Im_getting_very_inconsistent_results_when_capturing_an_IR_message_using_a_VS1838b_IR_demodulatorWhile not using this library but the built-in peripheral of ESP32, with the VS1838 I've also been getting bad reception, and sudden interrupts for IR events even when not pressing any remote within the nearest few hundred meters of the device... Swapped it out for a Sharp unit from a local parts shop and things suddenly became super smooth!

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: March 12, 2025, 03:42:42 pm
content: If you want a simple, cost-effective fix, try a higher-quality IR remote. Use a different IR receiver module with better filtering. The TSOP38238 or TSOP4856 are better at rejecting ambient IR noise.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 12, 2025, 03:57:33 pm
content: As suggested, use a ready made IR detector.They have built in ambient light rejection and some filtering. You can add this function of course.Seehttps://www.ti.com/tool/CIRCUIT060041Any small npn will work. eg 2N3904 or a BC547.The TSOP1738 is obsolete. Consider all sources as dodgy. The TSOP93538 is current and very cheap say $0.33, though when trump has finished fixing things more like a hundred dollars a piece.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 12, 2025, 08:49:11 pm
content: Quote from: daxliniere on March 09, 2025, 11:42:16 pmIt seems like it mostly works?More drive on the transmission side certainly helps, but really bright direct sunlight can swamp the IR RX,so physical shades may be needed.You could also look at adding a second RX, eg one rear facing to catch reflections off a wall ?

author: tooki
author_rank: Super Contributor
timestamp: March 12, 2025, 09:11:46 pm
content: Quote from: daxliniere on March 09, 2025, 11:42:16 pmFirst of all, get a better IR receiver. As others have stated, that model was actually discontinued years ago and then copied.The big player in IR receivers is Vishay, which makes a huge array of receivers tuned for every protocol. So your first step is to identify the IR code and carrier your remote is using. (Probably NEC for those cheap things, but make sure.) Then go to the Vishay website, browse to IR receivers, select the code type, and then choose a corresponding one of the newest-generation ("Cyllene 2" series) receivers (TSOP32, 33, 34, 36, 37, 38, 39, 75). There's also a PDF selection guide, but it's not quite current:https://www.vishay.com/docs/49845/sg2145_infrared_receivers.pdf(See also:https://www.vishay.com/docs/80076/introductionpartnumbers.pdf)Vishay has tons of documents on IR receivers, including mechanical design of the enclosure and pretty much any aspect of IR remotes:https://www.vishay.com/en/how/onlineliterature/online-libraries/?category=22The remote control may also be an issue. Those slim remotes tend to be kinda weak.Quote from: Terry Bites on March 12, 2025, 03:57:33 pmThe TSOP93538 is also outdated, it's now one generation behind ("Cyllene 1").

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 12, 2025, 10:01:22 pm
content: Quote from: tooki on March 12, 2025, 09:11:46 pmand there is now a New Cyllene 2 IChttps://www.vishay.com/en/company/press/releases/2025/VSOP383xx/Claimsthe enhanced solutions provide drop-in, plug and play replacements for existing devices in the series, while offering a wider supply voltage range from 2.0 V to 5.5 V, 37 % higher dark-ambient sensitivity, and improved performance under strong DC light and Wi-Fi noise.

author: tooki
author_rank: Super Contributor
timestamp: March 13, 2025, 07:53:33 pm
content: Quote from: PCB.Wiz on March 12, 2025, 10:01:22 pmMy post you quoted above literally says this:Quote from: tooki on March 12, 2025, 09:11:46 pm

author: daxliniere
author_rank: Regular Contributor
timestamp: March 16, 2025, 03:49:56 pm
content: Hey everyone, thank you SO much for sharing your knowledge and experience on this.Okay, so my plan going forward will be to change the IR receiver for something more recent, but also to change the remote control. I hate the CR2025 battery remotes anyway and would want to use something that takes AA or AAA batteries. My only concern is choosing a specific IR receiver now and later finding out that the custom remotes I'll order use a different frequency.(As an aside, since last night I managed to solve an issue that the IRremote lib was causing. It uses TIMER2 by default and this is also used for PWM on some pins. Using IRremote broke PWM on one pin and engaging PWM on that pin caused IRremote to crash and cease reading the IR receiver pin. Fixed by putting#define IR_USE_AVR_TIMER5before#include <IRremote.h>.)

author: Peabody
author_rank: Super Contributor
timestamp: March 16, 2025, 04:25:25 pm
content: Tell us more about ordering custom remotes.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 16, 2025, 06:26:19 pm
content: No matter the IR remote type, the 3 pins IR receiver remains the same. The 3 pins IR sensor/receiver does not decode, it only outputs a logic one when it sees chopped IR in the air. The IR commands decoding is done in software, by the microcontroller (or by the TV processor, etc. in case of IR controlled home goods). The IR sensor doesn't care about the model of the IR remote transmitter. IR remote + sensor are not "paired", like Bluetooth or radio channels are.Search for "universal IR remote control", or for "RC5 IR remote", and use any model you like. It will work with any 3 pins IR receiver + any Arduino.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 16, 2025, 07:24:08 pm
content: Thanks RoGeorge. I was aware that all decoding is done by the device connected to the IR receiver, nbut I'm a bit confused, as some other comments in this thread mentioned selecting an IR receiver of a specific carrier frequency using the Vishay website.EDIT: Yes, it seems that you need to select a receiver tailored to 36kHz or 38kHz carrier frequency. NEC protocol is 38kHz, so that narrows it down for me significantly.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 16, 2025, 07:28:28 pm
content: Sure!If you go onto Alibaba.com you will find millions of manufacturers of pretty much everything you can imagine. I did a search for "custom IR remote control" (https://www.alibaba.com/trade/search?spm=a2700.galleryofferlist.the-new-header_fy23_pc_search_bar.keydown__Enter&tab=all&SearchText=custom+IR+remote+control)The only things you need to be aware of are that there are MOQs (minimum order quantities) which vary wildly from one manufacturer to the next. Also be aware that shipping costs are crazy high, nothing like what we experience as consumers on sites like AliExpress (which, ironically, is a spin-off of Alibaba.com)

author: tooki
author_rank: Super Contributor
timestamp: March 16, 2025, 08:52:17 pm
content: Quote from: RoGeorge on March 16, 2025, 06:26:19 pmNo, but it does care about what carrier frequencyand what protocolare being used, as the AGC (automatic gain control) circuitry is tuned for the protocol. Using a receiver optimized for a different protocol, even if the correct carrier frequency is used, can cause severe performance degradation.With that said, as you said, the pinouts are the same (especially if one selects within the same series), so swapping out for a different model after the fact is no trouble at all. Not to mention that I expect that a custom remote can be ordered with whatever protocol one wants.Quote from: RoGeorge on March 16, 2025, 06:26:19 pmFor the most part.Apple actually did enable optional remote pairing with its IR remotes, but it worked not by having the remote pair to a device, but by having the device pair to a remote! Each remote sent an ID prefix before the otherwise normal IR commands, and once paired, a device would simply ignore those commands from remotes with a different ID. And since the number of IDs wasn’t very big, and thus ID collisions could occur, there was even a way to change a remote to another ID, if you had multiple different devices in the same room (like an Apple TV box and a Mac, or iPod dock).

author: tooki
author_rank: Super Contributor
timestamp: March 16, 2025, 09:18:05 pm
content: Quote from: daxliniere on March 16, 2025, 03:49:56 pmAs RoGeorge said, the pinouts are the same. Choose the receiver series you want, and if need be you can swap out the specific receiver after the fact.But as I said above, you should be able to choose whatever protocol you want when ordering a custom remote.Would I order a custom remote for a one-off project? Nah. I’d reuse the remote to some obsolete or obscure device, like a VCR remote found at a thrift store or something. You could modify it into a custom case if desired. Or I’d build one entirely from scratch (with the bonus that I could put in some absurdly powerful IR transmitter in it*).Quote from: daxliniere on March 16, 2025, 07:24:08 pmNot just the carrier frequency. The carrier frequencyand code(protocol), in that the protocol determines which AGC type is optimal.Look at the selection guide I linked to earlier:https://www.vishay.com/docs/49845/sg2145_infrared_receivers.pdfIt plainly shows that for 38kHz NEC and Sharp codes, the best AGC is AGC4 (or AGC6 in certain receivers, which reduces interference from smartphone proximity sensors, according to a different application note), while for the remaining 38kHz codes (Mitsubishi, RECS-80, etc), AGC3 is best.Look at the screenshot attached: go to vishay.com, click Products, then IR Receivers, then when that page loads, click the IR Receivers tab, then choose the code you will use.*IR transmitter LEDs are intended to be driven at very high currents. An ordinary IR LED designed for 50mA continuous may be specified for 1-1.5A (yes, amps) pulsed, because IR remotes use a very low duty cycle. Often, clueless hobbyists drive them at just 20-50mA pulsed, resulting in terrible performance.

author: tooki
author_rank: Super Contributor
timestamp: March 16, 2025, 09:23:22 pm
content: See also this fantastic overview of the codes themselves:https://www.vishay.com/docs/80071/dataform.pdf

author: daxliniere
author_rank: Regular Contributor
timestamp: March 16, 2025, 11:46:25 pm
content: Thanks again, Tooki, this is awesome! This thread has revealed even more than I could have imagined and hoped for.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 17, 2025, 07:24:02 am
content: Quote from: daxliniere on March 16, 2025, 07:24:08 pmThere is indeed a carrier frequency for the IR receiver, but the filter is not that sharp. The carrier match is a nice to have, in case you want maximum range. In practice, it will work anyway no matter which carrier is used by the remote. In the same room it will work even if you point the remote to the ceiling, or even backwards.38kHz is probably the most common carrier. When I first bought the first IR sensors, got the same worries as you have now, so I've bought TSOP1738, 1735, 1740, and so on (last to digits encodes the carrier frequency for this models), all the frequencies I could find on that shop (it was a brick and mortar).When I've arrived home, to my surprise, they all worked with the same remote.Then I've noticed they work withanyremote I could find around the house (about 5-10 IR remotes). Later, I've recovered a few other sensors and remotes from retired or defective household items, and they all seem to work just fine, no matter which IR remote/carrier is used (in a 4 by 5 meters room).

author: Peabody
author_rank: Super Contributor
timestamp: March 17, 2025, 02:32:12 pm
content: That's been my experience too. But I guess in theory, a mismatch could also affect the On/Off detection periods. So the receiver might be slower to detect carrier aquisition, and quicker to detect loss of carrier, and the On periods would then be shorter than the Off periods in something like NEC in which they can actually be equal in transmission. So that could be a problem even at short range, but I think most receiving logic is pretty forgiving, and in practice I haven't seen a problem.I suspect the same would be true if the IR wavelength differed from the typical 940nm. But you know, if you're ordering a custom remote, you would just make sure everything matches anyway.

author: tooki
author_rank: Super Contributor
timestamp: March 17, 2025, 06:41:10 pm
content: Yep. It's not that it won't work at all (for the most part), but that it's not optimal.For example, the Vishay "data formats" document I linked above says this about the NEC code:QuoteI vaguely recall reading somewhere, either in Vishay's vast documentation or in the documentation for one of the IR libraries, that some codes are so much longer or shorter than most that some of the AGC options will basically filter them out. (Maybe Sony? Vishay now has some models with an "AGC-S" option specifically for Sony code.)The other thing that's non-obvious is that lots of modern technology causes much more interference than was around in the past: Wi-Fi and Bluetooth, high-frequency fluorescent, PWM-dimmed LED, and various sensors in our gadgets all cause opticalor electromagneticinterference that the high-gain photodiode amplifier needs to filter out -- without filtering out the IR carrier and the code. IR is super-simple, until it's not.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 17, 2025, 11:13:20 pm
content: Quote from: tooki on March 17, 2025, 06:41:10 pmHa! Ain't that the truth!

author: Buriedcode
author_rank: Super Contributor
timestamp: March 18, 2025, 12:25:18 am
content: Just to add, the nice thing about IR compared to RF is - whilst the receivers may send out a few litches from time to time, generally, with no transmitter, or something with no carrier frequency, its output doesn't change. This is compared with RF which will just receive raw noise, which is why packets include long preambles and sync bytes to let the receiver know there is data incoming, rather than the random string of 1's and 0's it spits out continuously.This means that decoding IR, be it RC5, NEC or Sony protocols (or even custom protocols) is usually as simple as an IO edge interrupt on a microcontroller that measures the time between rising or falling edges. You can even do polling if the MCU is very busy with other tasks. With RF, you may eventually get a fairly nice stream of 1's and 0's after the preamble, there will be glitches that means there may be several edgesin the middleof a bit that will trigger edge detection on the micro and screw up the timing.The above is often why the channel coding, clock recovery and error detection/correction thats required for RF has moved to system-on-chip IC's that handle all the "RF stuff" digitally, meaning the host MCU just has to give it data to send, or collect data and not worry about all the minutiae. I've done it all from scratch and for a reliable communication channel it's frustrating and challenging.For control purposes -if you can use IR, do it.The handy IR receiver modules are great, and the protocol can be nice and simple. One tip: Put an RC filter on its power line, like 47-150R and 47uF, as they are very sensitive to power supply noise, but use such low current that a heavy RC filter works well.If no line of sight is available, an off-the-shelf standard/RF module(RFM69, CC2500 etc..), because it can get very complicated quickly. Thank you for listening to my TED talk.

author: tooki
author_rank: Super Contributor
timestamp: March 19, 2025, 03:38:02 pm
content: Indeed, Vishay recommends just such an RC filter in noisy environments. (Their application note shows 330 ohms and 2.2μF, but I very much doubt the values are critical.)

author: Buriedcode
author_rank: Super Contributor
timestamp: March 20, 2025, 06:04:25 am
content: Quote from: tooki on March 19, 2025, 03:38:02 pmI only recently did a small project that required them, and was surprised at just how low power some are - I managed to use one as a proximity sensor (IR based, pretty crude) and kept the average current consumption down to 100uA. I think its peak continuous current was 0.3mA - but ran that at 1/3 duty.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 27, 2025, 11:36:23 am
content: The supplier I usually use for electronic parts (CPC/Farnell) only stocks one Vishay 38kHz IR receiver with AGC4 (TSOP2438). They're pretty cheap and I need some other parts from them so I'll get a couple and see how they go.Can't be any worse than the VS1838B I'm currently using, though it will be interesting testing both in sunlight.Stay tuned!

author: daxliniere
author_rank: Regular Contributor
timestamp: March 27, 2025, 11:42:50 am
content: Regarding the filtering, I already have 100uF at the 12v input and 47uF at the MCU's 5V regulator output, but will add another after the IR receiver's 150R current limiting resistor (powered from +5v).Can I use another of the same 47uF 35v MLC capacitor for this? It would simplify the BOM.

author: artag
author_rank: Super Contributor
timestamp: March 27, 2025, 07:05:16 pm
content: Quote from: ftg on March 10, 2025, 09:07:23 amAgreed, but it's not clear to me if this is a one-off that can use a cheap packaged link or other remote, or a product that needs to meet licencing standards. If the latter then yes, it's a huge pain. If the former, then unless there's a simple clear path from transmitter to receiver (as with a TV remote) then optical just isn't very good. Big Clive recently reviewed some convenient little wireless remotes for switching USB. They're only on-off but there are also convenient keychain remotes with 4 buttons.

author: electronix27
author_rank: Contributor
timestamp: March 28, 2025, 01:25:02 pm
content: Built this in 2017, so not sure if this chip set and inexpensive transmitter/receiver is still available. I made this circuit to control a traffic light via remote control. The four buttons were, off, red-yellow-green sequence, flash red, flash yellow. The TX/RX modules were 315 Mhz, and the chipset made by Princeton Technology had three specific reciever decoder chips which were either, momentary, toggle or latching. I used the latching chip. The tri-state, 8 bit address needed to match of course on both encoder and decoder, then 4 bit output state would be made. You didn't mention how many relays were switched in your design. This RF setup worked great for me.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2025, 04:27:42 pm
content: Quote from: daxliniere on March 27, 2025, 11:42:50 amI think you misunderstand: that’s not a current limiting resistor; it doesn’t need one.The resistor and capacitortogetherform an RC filter. And it needs to be right at the receiver; having it way over somewhere else doesn’t count.Quote from: daxliniere on March 27, 2025, 11:42:50 amShould be just fine.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 28, 2025, 11:49:26 pm
content: Hi @Tooki,I had read from multiple sources that it was a good idea to add a current-limiting resistor to these IR receivers. I think I used 150R in my prototype.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 29, 2025, 12:46:40 am
content: Hey Artag,Ideally, I would like to try a Kickstarter campaign to see if I can sell a hundred or so units, but initially, I'm just making 3 or 4 prototypes to loan to friends for testing and feedback.I think that IR is definitely the best route. As much as I'd like to include a custom remote, perhaps that would have to be a 'stretch goal' so as to meet the minimum order quantities of customised IR remotes.What I'mhopingis that using a higher quality IR receiver (Vishay), the cheaper flat CR2025-type remotes work acceptably well. (even though I want units that use AA or AAA batts cos CR2025s suck.)

author: Buriedcode
author_rank: Super Contributor
timestamp: March 29, 2025, 01:53:32 am
content: Quote from: daxliniere on March 28, 2025, 11:49:26 pmThen those sources have misunderstood the purpose of the resistor. Note, I'm not aruing that you don't need or sohuld use a resistor, but about its function."Current limiting" resistor application, implies a circuit/component that is drawing current, and a resistor is used to limit this current. Just like an LED, any voltage over its forward voltage (~1.6V for red, ~3.1V for blue) will allow current to flow. However, if you look at the I/V curve you'll see that once you go over its forward voltage it can conduct significant current - more than enough to destroy the LED - so a resistor is used in series to limit this current. For 9V supply, and a 2V LED, the voltage across the resistor will be 9V - 2V = 7V. If a 1k resistor is used, thats V= IR therefore I = V/R = 7V / 1k = 0.007A -or 7mA. Thats resonable.Without a resistor, that 7V will be across the connections/wires between the voltage source and the LED, which may be much less than 1 ohm. So now we have I = V/R = 7V / 1 = 7A! 7 amps will happily destroy all but the largest LED.These IR recevier devices draw very little current at their rated voltage (or voltage range since many operate between 2.0 and 5.5V). There is no need for limiting their current. The resistor is placed in series with its power input,also with a large capacitor from that power pin to ground. This forms an RC low pass filter, that greatly attenuates any ripple or noise on the power line to the device.This is helpful because these devices are very sensitive to noise/power supply ripple that is near its centre frequency, and noise/ripple really is everywhere to a certain extent.I guess people call it "current limiting" because they have seen resistors in series with other components (such as LEDs) and figured that is what they are called - and they arein that particular application.Sorry for the long winded explanation, wasn't meant to berate you or criticise you in any way, just wanted to clarify in case others read the thread

author: daxliniere
author_rank: Regular Contributor
timestamp: March 29, 2025, 02:00:15 am
content: Quote from: Buriedcode on March 29, 2025, 01:53:32 amNo no, not at all!Thank you for taking the time.I was aware of current limiting with components such as LEDs, and I will admit that it was surprised by the suggestion of needing one for an IR receiver, but I'm certainly no expert and I figured it wouldn't hurt.There definitely wasn't any mention of a cap in the places I saw the current limiting resistor suggestion, but I will be adding an RC filter to my design for sure.Will 150R + 47uF do the trick for the +5v that it's running on?

author: tooki
author_rank: Super Contributor
timestamp: March 29, 2025, 10:21:25 am
content: Quote from: daxliniere on March 29, 2025, 02:00:15 amThose values give you a cut-off frequency of about 23Hz (and since that arrangement is a low-pass filter, it means that frequencies below 23Hz get through, frequencies above get attenuated), which is probably fine. Vishay’s own recommendation has a cut-off frequency of around 220Hz, so they clearly don’t think it’s necessary to go below that, and yours encompasses that and more, so your values will work as well as or better than their suggestion.

author: tooki
author_rank: Super Contributor
timestamp: March 29, 2025, 10:32:41 am
content: Quote from: daxliniere on March 28, 2025, 11:49:26 pmI could find only one, a post on electronoobs.com. Every other instance was people referring to the current limiting resistor of the LED on the transmitter. (With the usual mistake of limiting it to 20-50mA, not realizing that IR remotes pulse the LEDs at vastly higher currents.)

author: Peabody
author_rank: Super Contributor
timestamp: March 29, 2025, 02:51:26 pm
content: When ordering the remote, are you able to specify how much power you want it to produce? That would seem to be key. I recently made a special-purpose remote powered directly by an 18650 (no regulator), with a 5Ω current limiting resistor, 30% duty cycle. That's not particularly high current for a remote, but it works quite well from like 50 feet. But it's not used in the sun. And I've seen remotes that use twin IR LEDs, which I assume are in parallel. Anyway, it seems to me that the sunlight problem is mainly solved by shielding the receiver from direct sun, but also having enough transmit power in case the shielding also shields the receiver from the remote a bit.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 29, 2025, 09:08:57 pm
content: Quote from: Peabody on March 29, 2025, 02:51:26 pmThe custom order I'm looking at would just be custom decal printing, rather than an entirely new PCB design.

author: ME
author_rank: Frequent Contributor
timestamp: March 30, 2025, 10:08:08 am
content: why no mention of an ultrasonic remote control, My gran had a tv with one in the 1970's, used to drive her dogs nuts! lol.

author: tooki
author_rank: Super Contributor
timestamp: March 30, 2025, 03:12:39 pm
content: Maybe because nobody uses that technology for remotes anymore? To the best of my knowledge, ultrasonic has no advantages over infrared for remote control applications.

author: daxliniere
author_rank: Regular Contributor
timestamp: March 30, 2025, 07:30:18 pm
content: This made me chuckle.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 30, 2025, 10:02:20 pm
content: Quote from: tooki on March 30, 2025, 03:12:39 pmNot needing a battery is a significant one. That said, there are RF remotes that don't use batteries, pressing the button generates a bit of current to run the transmitter.

author: tooki
author_rank: Super Contributor
timestamp: March 31, 2025, 07:48:37 pm
content: Quote from: NiHaoMike on March 30, 2025, 10:02:20 pmNot all ultrasonic remotes were mechanical tuning-fork–based doodads. There were plenty of electronic ones, too. Those need batteries.