Simple MP3 speaker project (beginner)  - Page 1
Forum section: electronics / beginners

author: pitch
author_rank: Newbie
timestamp: August 25, 2025, 01:54:34 pm
content: I would like to create a small MP3 speaker for a young child. I have never done any electronics work before, and this seems like an interesting and useful project to start with (and hopefully not too difficult).In terms of functionality, I'm looking to make something as simple as possible. In the lists below, ✓/✗/? indicate whether the feature is available based on the diagram.Required✓ A button allows you to turn the speaker on and off✓ The speaker plays songs stored on a memory device. It must be possible to add or delete songs (e.g. by opening the case and removing the storage device)? The speaker automatically plays the next song when a song's over (I’m not sure whether this is the default).✓ The speaker runs on battery power. The battery can be charged via a USB-C port.? The speaker must be safe for a young child.Optional✓ Buttons allow you to adjust the volume✗ Manage memory device directly by connecting the speaker to a computer via the USB-C port✓ Previous and next buttons allow you to navigate through songs.✓ Play/Pause button allows you to pause and resume the current song.✗ A LED indicates whether the device is turned on.A LED indicates the battery status (✗low battery, ✓ in charge, ✓ charging completed).ComponentsPlease let me know your thoughts on the components, whether they are correct, and whether everything is listed or if anything is missing.DFPlayer Mini (it is labelled as “DFFirst-Mini but I assume it’s basically the same)http://aliexpress.com/item/1005006462929348.html?spm=a2g0o.productlist.main.1.3a0843ccPOwzar&algo_pvid=0f27b678-cf49-438e-8f71-ca2209441dc6&algo_exp_id=0f27b678-cf49-438e-8f71-ca2209441dc6-0&pdp_ext_f=%7B%22order%22%3A%221526%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis!EUR!1.13!0.99!!!9.26!8.14!%402103894417557235554178008e4ed4!12000037284973820!sea!FR!0!ABX!1!0!n_tag%3A-29910%3Bd%3Aa11067ad%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046648&curPageLogUid=QrCEwtrif5A5&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005006462929348%7C_p_origin_prod%3AMicro-SD 8GB + SD Adapterhttps://www.amazon.fr/microSDHC-Adaptateur-Performance-Smartphones-Tablette/dp/B00FEFFVRI?__mk_fr_FR=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1V29ZALZKRSKH&dib=eyJ2IjoiMSJ9.aZssZpZDJ6P_YRoGIIjlbQDjs-odj5k39BbMO51g-g_eWqEYbaiMkBgJty_2jxnhEHYNIjJ6PsqeDL89qTsVuM4RtkX33asSJ4X1LRsOt5HWQkhFRhwcLeZOn-pTcG4WrckDNceKoQZBuQyxT1XNWbNhIDS6ubuTElRK_VSY7dw7QpfOAv8PQSZ-LSm3sjHs1RQX0o3m7ogMK3kooIZdbTZuqC9WHFCSID789B5UVLQMYEEmJcE5HdnzaVGkrO_V8UUhlzlwrCngF57JLcB7ETdwcZjE91eeeSlN5WboJXE.VdCsXsaejx6VZUg6OJELKXEsByqUYH7r9QhnuHtaXew&dib_tag=se&keywords=carte%2Bmicro%2Bsd&qid=1755724225&refinements=p_n_feature_seven_browse-bin%3A410569031%7C410570031%7C410571031%7C410572031%2Cp_n_condition-type%3A15135266031%2Cp_36%3A-1000&rnid=428393031&s=computers&sprefix=carte%2Bmicro%2Bsd%2Caps%2C113&sr=1-4&th=1Speakerhttps://fr.aliexpress.com/item/1005005699690954.html?spm=a2g0o.productlist.main.1.418b3c23S6Csj3&algo_pvid=d904abd9-f653-4167-b0ca-ea88a2b094fe&algo_exp_id=d904abd9-f653-4167-b0ca-ea88a2b094fe-0&pdp_ext_f=%7B%22order%22%3A%221735%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.36%210.99%21%21%2111.04%218.09%21%40211b61a417559806863274731e7a9a%2112000044410686572%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046648&curPageLogUid=3x8JI99xpU5z&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005699690954%7C_p_origin_prod%3APush button (on/off - 3-6V, Self locking, 10mm)https://fr.aliexpress.com/item/1005005628118782.html?spm=a2g0o.productlist.main.17.73ca598azYeEwr&algo_pvid=53f640b3-8e1d-49d4-9e6f-5c335a45508b&algo_exp_id=53f640b3-8e1d-49d4-9e6f-5c335a45508b-16&pdp_ext_f=%7B%22order%22%3A%221220%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.35%210.99%21%21%211.54%211.13%21%40211b876717557876344027556eb153%2112000033804112921%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046651&curPageLogUid=ppmudrrDlwvI&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005628118782%7C_p_origin_prod%3APush button (on/off) with green led (alternative to above, 3-9V, Self locking, 12mm)https://fr.aliexpress.com/item/1005005628118782.html?spm=a2g0o.productlist.main.17.73ca598azYeEwr&algo_pvid=53f640b3-8e1d-49d4-9e6f-5c335a45508b&algo_exp_id=53f640b3-8e1d-49d4-9e6f-5c335a45508b-16&pdp_ext_f=%7B%22order%22%3A%221220%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.35%210.99%21%21%211.54%211.13%21%40211b876717557876344027556eb153%2112000033804112921%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046651&curPageLogUid=ppmudrrDlwvI&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005628118782%7C_p_origin_prod%3AWires (for breadboard and soldering)https://fr.aliexpress.com/item/1005009005078104.html?spm=a2g0o.productlist.main.11.62f077352xCQe7&algo_pvid=5ec07237-3ada-4306-b335-4a195cd4e64b&algo_exp_id=5ec07237-3ada-4306-b335-4a195cd4e64b-10&pdp_ext_f=%7B%22order%22%3A%2284%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.73%210.99%21%21%2114.09%218.12%21%40211b813b17557877734698937edaee%2112000047542229468%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046651&curPageLogUid=G6RSYFbTPMQw&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005009005078104%7C_p_origin_prod%3AWires female to male (for breadboard, I’m not sure they are required, and if other types such as female/female are required)https://fr.aliexpress.com/item/1005009324361092.html?spm=a2g0o.productlist.main.12.62f077352xCQe7&aem_p4p_detail=20250821074933965342042495620003282044&algo_pvid=5ec07237-3ada-4306-b335-4a195cd4e64b&algo_exp_id=5ec07237-3ada-4306-b335-4a195cd4e64b-11&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.28%211.28%21%21%2110.44%2110.45%21%40211b813b17557877734698937edaee%2112000048755390325%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895&curPageLogUid=cdZG43vPmdWK&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005009324361092%7C_p_origin_prod%3A&search_p4p_id=20250821074933965342042495620003282044_3Breadboardhttps://fr.aliexpress.com/item/1005004532352681.html?spm=a2g0o.productlist.main.6.40ba424eUU61ae&algo_pvid=563f24f2-e8c9-4b98-be14-e21cfdc8d6fe&algo_exp_id=563f24f2-e8c9-4b98-be14-e21cfdc8d6fe-5&pdp_ext_f=%7B%22order%22%3A%223843%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.14%210.99%21%21%211.30%211.13%21%40210385db17557879853347686ea4d1%2112000029785371583%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046650&curPageLogUid=rWso2u9SDcu8&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005004532352681%7C_p_origin_prod%3APCB protoboardhttps://fr.aliexpress.com/item/1005006100148769.html?spm=a2g0o.productlist.main.3.739dfc2dj2WFos&algo_pvid=69c2b699-a32b-4732-b16c-96ff7645a8d8&algo_exp_id=69c2b699-a32b-4732-b16c-96ff7645a8d8-2&pdp_ext_f=%7B%22order%22%3A%222205%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%210.89%210.86%21%21%217.27%217.06%21%40211b618e17557880996141723e7f38%2112000035755220382%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895&curPageLogUid=smOR39gGu7Hb&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005006100148769%7C_p_origin_prod%3ASoldering kithttps://fr.aliexpress.com/item/1005005623832147.html?spm=a2g0o.productlist.main.1.6b8642e1n8icIp&algo_pvid=0abab38a-da99-466c-9d18-99b99cdab563&algo_exp_id=0abab38a-da99-466c-9d18-99b99cdab563-0&pdp_ext_f=%7B%22order%22%3A%2220593%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%215.12%210.99%21%21%2141.77%218.07%21%40211b431017557882794955539e3037%2112000033826061946%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046651&curPageLogUid=QE7bo59wBCEA&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005623832147%7C_p_origin_prod%3A3x self-reset buttons (for volume and previous/next)https://fr.aliexpress.com/item/1005005628118782.html?spm=a2g0o.productlist.main.3.6e0456c0HVJHU4&algo_pvid=60ac27fe-90d3-447f-b1ed-7af18ed2ce2a&algo_exp_id=60ac27fe-90d3-447f-b1ed-7af18ed2ce2a-2&pdp_ext_f=%7B%22order%22%3A%221220%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.35%210.99%21%21%211.54%211.13%21%4021038e1e17557902310024721e0798%2112000033804112921%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046651&curPageLogUid=RSK5vdGhk3Em&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005628118782%7C_p_origin_prod%3A33k resistorhttps://fr.aliexpress.com/item/1005005855324735.html?spm=a2g0o.productlist.main.1.29db3tOO3tOOE6&algo_pvid=d2696b4a-8852-42e1-bc7d-ce2b54857489&algo_exp_id=d2696b4a-8852-42e1-bc7d-ce2b54857489-0&pdp_ext_f=%7B%22order%22%3A%225081%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%211.90%210.99%21%21%212.15%211.12%21%40211b628117560670100015791e53f1%2112000034587357832%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046648&curPageLogUid=OAQJcTjMgwOT&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005855324735%7C_p_origin_prod%3ACase (I don't have a 3D printer, I'm looking for something safe for young kids. I’m not sure about the size, since I assume it mostly depends on the battery size, I was thinking 10 x 6 x 2.5 cm)https://fr.aliexpress.com/item/1005008679795475.html?spm=a2g0o.productlist.main.6.143aLFCaLFCaSL&algo_pvid=7ebbd290-80ee-4457-98b3-ec17ba20311b&algo_exp_id=7ebbd290-80ee-4457-98b3-ec17ba20311b-5&pdp_ext_f=%7B%22order%22%3A%22709%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%210.75%210.75%21%21%216.11%216.08%21%40211b612517558083404947280e5ad4%2112000046296222288%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A7391c6a5%3Bm03_new_user%3A-29895&curPageLogUid=r0KUqfnKuTWA&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005008679795475%7C_p_origin_prod%3ATransparent case (alternative to above one, 10 x 6.8 x 5 cm)https://fr.aliexpress.com/item/1005008701037241.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.7.4d6blTDrlTDrq1&utparam-url=scene%3Asearch%7Cquery_from%3Apc_back_same_best%7Cx_object_id%3A1005008701037241%7C_p_origin_prod%3A&algo_pvid=1aeedbcf-0e8a-4682-8372-3570e52671a9&algo_exp_id=1aeedbcf-0e8a-4682-8372-3570e52671a9&pdp_ext_f=%7B%22order%22%3A%22784%22%7D&pdp_npi=6%40dis%21EUR%212.44%210.99%21%21%2119.91%218.04%21%402103891017560638065646864e0809%2112000046317159302%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046648TP4056 USB-C charging modulehttps://fr.aliexpress.com/item/1005006043031985.html?spm=a2g0o.productlist.main.14.4cdb19kL19kLz9&utparam-url=scene%3Asearch%7Cquery_from%3Apc_back_same_best%7Cx_object_id%3A1005006043031985%7C_p_origin_prod%3A&algo_pvid=af49ec0c-d71a-4d76-8406-b199eba3070e&algo_exp_id=af49ec0c-d71a-4d76-8406-b199eba3070e&pdp_ext_f=%7B%22order%22%3A%226984%22%7D&pdp_npi=6%40dis%21EUR%211.99%211.81%21%21%2116.21%2114.79%21%40211b813f17559827128802992e4c1e%2112000035475416224%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-2989518650 batteries (I’m not sure how many batteries should be included, I assume 1 since it's 3.7V and the DFPlayer ranges from 3.3 to 5V)https://fr.aliexpress.com/item/32810182330.html?spm=a2g0o.productlist.main.1.65de65b7KcumJ8&algo_pvid=18b8c98a-ab14-4bc5-b90a-41f241e41d54&algo_exp_id=18b8c98a-ab14-4bc5-b90a-41f241e41d54-0&pdp_ext_f=%7B%22order%22%3A%228320%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%218.04%210.99%21%21%219.12%211.12%21%402103846917559829948813602e3577%2112000031504535312%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-29895%3BpisId%3A5000000174046648&curPageLogUid=0ugXqVNtA9xm&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A32810182330%7C_p_origin_prod%3ABattery case (I’m not sure how many cases)https://fr.aliexpress.com/item/1005005449039449.html?spm=a2g0o.productlist.main.5.3d811a98ZvdgYW&algo_pvid=a910361b-ef63-4f86-ab44-35041a784854&algo_exp_id=a910361b-ef63-4f86-ab44-35041a784854-4&pdp_ext_f=%7B%22order%22%3A%22932%22%2C%22eval%22%3A%221%22%7D&pdp_npi=6%40dis%21EUR%210.89%210.86%21%21%217.25%217.05%21%40211b6c1917559828704477115e2356%2112000033123840606%21sea%21FR%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ae7a79ab7%3Bm03_new_user%3A-29895&curPageLogUid=ffDSa9jqP5Z6&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005005449039449%7C_p_origin_prod%3AElectronic diagram1.I’ve seen some projects that include either a 1K resistor, a capacitor or a 10 kΩ potentiometer with the speaker, but I’m not sure what that’s for.2.I've read the VCC part may be hazardous if not managed correctly soI'm concernedabout the TP4056 + 18650 battery part (fire, explosion, etc.).

author: RJSV
author_rank: Super Contributor
timestamp: August 25, 2025, 05:09:24 pm
content: Generally, products get scrutiny for avoiding swallowing or choking hazards, especially if there are button batteries. Other guidelines for small children are likely available. Vcc, generally safe, but I'm actually not certified to give safety advice.I think might be possible to get a skin burn injury, from as low as 5 volts, but that's in wet conditions. The activity, to take a battery out, with screwdriver etc. is likely way more dangerous. Never use force, with a tool, when near the body, I bet that reckless use of tools causes a lot of minor injuries.That, I mean, might mean that you might buy a perfectly safe kit, but then get an injury from one of your tools, while working on the kit.Eyes and fingers need extra caution. (So, wear YOUR safety glasses, along with the kid, watching you work.)Great projects out there, all in all.

author: pitch
author_rank: Newbie
timestamp: August 25, 2025, 08:13:20 pm
content: Thanks for your feedback. The kid woudn't be watching me working, so my concern is, as you mentionned, mostly choking hazard, burn injuries, etc.Appart from the above concerns, I'd also like to make sure the project would be working. Any feedback on this end (components, diagram, etc.)? Thanks!

author: mariush
author_rank: Super Contributor
timestamp: August 25, 2025, 08:23:52 pm
content: Get a cheap mp3 player , open the case, solder wires to the pads to connect your big buttons...Example 10$ for this one :https://www.amazon.com/Battery-Portable-Support-Students-Running/dp/B0CMTYVT9T/has play/pause, next , previous , volume up and downreplace battery with a bigger one for longer life if you want.add a small stereo/mono amplifier that can run from a lithium battery ... ebay is full of small boards that also have bluetooth which you don't needhere's an example , mono amplifier running on single battery :https://www.digikey.com/en/products/detail/adafruit-industries-llc/2130/5761279another examplehttps://www.digikey.com/en/products/detail/adafruit-industries-llc/3006/6058477orhttps://www.digikey.com/en/products/detail/dfrobot/DFR0119/6588490If the buttons are big enough you could even let the device be in its natural case, get a smaller box and make a cutout big enough just to expose the buttons and glue/tape/lock the player to the case, and put the amplifier in the box and speaker(s) on the sides of the box.

author: RJSV
author_rank: Super Contributor
timestamp: August 26, 2025, 12:27:14 am
content: My interpretation, on viewing that schematic, would be that there is stereo output just called SPKR1 and SPKR2. Each output normally relative to ground. So connection, with a pair, or just one will use ground on one side.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 26, 2025, 12:33:23 am
content: BTW, and this is just a side note, but as a courtesy to those who read your posts, please learn to trim your URLs!That Amazon URL that takes up 11 lines (!!!) in your post? It reduces down to this:https://www.amazon.fr/microSDHC-Adaptateur-Performance-Smartphones-Tablette/dp/B00FEFFVRIClue:look for a question mark (?) in the URL.Delete that and everything that follows.What's left will be the URL for that item.Everything else is just stuff that's specific to your browser "session", stuff that we don't care about out here.