Hey I am new to the forum and New to designing simple circuits. I have built a few guitar pedals and this has made me want to look into other types of circuits I could be making. I am constantly losing things and spend most of my time looking for things I need. I would like to make a device that makes a beep or chirp when I press a button wirelessly. I see a ton a stupid devices on the market to help people find misplaced items... they are generally overpriced and overly complicated requiring apps, subscriptions, etc. It would like it to be as simple as possible. could I do this without needing an engineering degree? What technologies do I have available to me as way of communication with the device? would IR work in this case? or utilize radio frequencies? Even if the thing was able to arbitrarily receive radio stations through unshielded wiring and play that out a little speaker to help me locate the item would work for me. I would like to be able to turn it on and off using a remote switch.

 

----> https://www.temu.com/anti--finder-alarm-with-led-light-and-sound-alert-abs-keychain-locator-with-whistle-function-outdoor-hiking-accessory-1pc--operated-36v-or-below-voltage-g-601099666481715.html?_oak_mp_inf=ELPE4eCm1ogBGiBhYmRiMzNmYTdjNjM0ZDZlYjBkMGNlMmE2ZDI0OWI5ZSCpkLCwwDI=&top_gallery_url=https://img.kwcdn.com/product/fancy/adc33ad0-7548-4cbb-93d2-50d7260c9121.jpg&spec_gallery_id=2512204360&refer_page_sn=10009&refer_source=0&freesia_scene=2&_oak_freesia_scene=2&_oak_rec_ext_1=MTUz&_oak_gallery_order=1233117173,1402734860,1322229871,929863053,1241208031&search_key=keychain finder&refer_page_el_sn=200049&_x_sessn_id=nlo9kfg2f6&refer_page_name=search_result&refer_page_id=10009_1735268240812_v58tlfw8n5

There is other flavors in many stores... ----> https://search.brave.com/images?q=keychain finder

 

You have chosen a very challenging project. For this to work, the receiver must be powered continuously while consuming very little power. At the same time, you would want it to be relatively small, no larger than a key fob. This limits the size of the battery to a coin cell and this is not going to last very long.

There are already such products on the market at a price you cannot beat.

Someone's review on the link posted above:
"handy on a key chain, serves their purpose, useful, nice product, useful, nice product loud and awesome for people like who misplace their keys! I love that u can turn it off when u find it so u can save the battery!"

"I love that u can turn it off when u find it so u can save the battery!"

This is absolutely senseless, because that is exactly when you are going to misplace your item.

 

Interesting project! For something simple, you could start with an RF transmitter/receiver pair or look into Bluetooth modules like BLE for low power. Wi-Fi might be overkill for range and battery. Honestly, though, existing products like Tile or AirTags are hard to beat for price and functionality—DIY is fun, but this one might end up more complex than expected.

 

In general, making something that is already available as a mass market item can only be useful as a learning experience. It will cost you way more than buying the item and will not perform anywhere close to the commercial version. If that is what you want, go for it. If you are trying to save money, forget it.