# Classic **URL:** https://forum.arduino.cc/c/official-hardware/classic/197.md [Latest](https://forum.arduino.cc/latest.md) · [Categories](https://forum.arduino.cc/categories.md) --- ## [How to get the best out of this forum](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/1335251)
**Author:** [@system](https://forum.arduino.cc/u/system)\ **Replies:** 0\ **Last updated:** [December 24, 2024, 2:48am UTC](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/1335251 "2024-12-24T02:48:24Z")
Welcome to the Arduino forum! A guide explaining how to get the best out of this forum is available at the link below. Please read it: --- ## [About the Classic category](https://forum.arduino.cc/t/about-the-classic-category/1335250)
**Author:** [@system](https://forum.arduino.cc/u/system)\ **Replies:** 0\ **Last updated:** [December 24, 2024, 2:46am UTC](https://forum.arduino.cc/t/about-the-classic-category/1335250 "2024-12-24T02:46:28Z")
The foundational Arduino hardware products --- ## [Finding people with Arduino Yun boards to help test my updates](https://forum.arduino.cc/t/finding-people-with-arduino-yun-boards-to-help-test-my-updates/1461126)
**Author:** [@outbackhut](https://forum.arduino.cc/u/outbackhut)\ **Replies:** 8\ **Last updated:** [October 20, 2026, 4:26pm UTC](https://forum.arduino.cc/t/finding-people-with-arduino-yun-boards-to-help-test-my-updates/1461126 "2026-10-20T16:26:28Z")
I am looking for any of you kind hearted folk who have Yun boards to test my yun updates that get the original yun up to OpenWrt 25.12 with all the old Arduino bridge/dashboard/etc still intact and updated too. Let me k… --- ## [Arduino:samd core 2 versions behind on ARM hosts](https://forum.arduino.cc/t/arduino-samd-core-2-versions-behind-on-arm-hosts/1460569)
**Author:** [@customcontroller](https://forum.arduino.cc/u/customcontroller)\ **Replies:** 2\ **Last updated:** [September 27, 2026, 8:47pm UTC](https://forum.arduino.cc/t/arduino-samd-core-2-versions-behind-on-arm-hosts/1460569 "2026-09-27T20:47:52Z")
I am setting up a build validation server on a Pi5 and have noticed the arduino:samd core is two versions behind on ARM64 hosts. I am working on a TinyUSB library for Arduino boards. Zero is very handy because it outputs… --- ## [Who is currently looking after the Yun system? Packages, OpenWRT, updates, etc](https://forum.arduino.cc/t/who-is-currently-looking-after-the-yun-system-packages-openwrt-updates-etc/1461110)
**Author:** [@outbackhut](https://forum.arduino.cc/u/outbackhut)\ **Replies:** 3\ **Last updated:** [September 27, 2026, 1:34pm UTC](https://forum.arduino.cc/t/who-is-currently-looking-after-the-yun-system-packages-openwrt-updates-etc/1461110 "2026-09-27T13:34:49Z")
So, I am currently working on a huge rebuild for the original Yun, using the most modern OpenWRT, keeping all the old Arduino stuff intact/updating. Who still controls the original? is it arduino? Who do I talk to so peo… --- ## [Arduino Micro Using USB-C causes issues with firmware/hardware functionality](https://forum.arduino.cc/t/arduino-micro-using-usb-c-causes-issues-with-firmware-hardware-functionality/1451467)
**Author:** [@ajpulzone](https://forum.arduino.cc/u/ajpulzone)\ **Replies:** 5\ **Last updated:** [July 10, 2026, 1:47pm UTC](https://forum.arduino.cc/t/arduino-micro-using-usb-c-causes-issues-with-firmware-hardware-functionality/1451467 "2026-07-10T13:47:02Z")
Situation: We have integrated bidirectional communication with an arduino micro into software we've created, this software also communicates with multiple other hardware components at the same time. The arduino micro r… --- ## [Arduino Pro Mini Help](https://forum.arduino.cc/t/arduino-pro-mini-help/1450734)
**Author:** [@wdpalma](https://forum.arduino.cc/u/wdpalma)\ **Replies:** 11\ **Last updated:** [July 6, 2026, 6:12pm UTC](https://forum.arduino.cc/t/arduino-pro-mini-help/1450734 "2026-07-06T18:12:17Z")
Hi gang, I'm having a hard time programming my Arduino Pro Mini 3.3V 8MHz microcontroller. I've spent a couple days now with the help of Google's Gemini AI but I continually get a timing error as I initiate the code dum… --- ## [Pro Mini sleep mode only 3.45 mA](https://forum.arduino.cc/t/pro-mini-sleep-mode-only-3-45-ma/1448814)
**Author:** [@kentm](https://forum.arduino.cc/u/kentm)\ **Replies:** 52\ **Last updated:** [June 20, 2026, 10:59pm UTC](https://forum.arduino.cc/t/pro-mini-sleep-mode-only-3-45-ma/1448814 "2026-06-20T22:59:10Z")
I am trying to reduce the current draw on a Pro Mini 3.3V. I'm powering the bare naked board using a 4-AA battery pack hooked up to RAW. The current draw is 6.24 mA upon startup, and 3.45 mA after going into sleep mode … --- ## [Mini Pro overhearing and burning out when connected to Darlington chip](https://forum.arduino.cc/t/mini-pro-overhearing-and-burning-out-when-connected-to-darlington-chip/1448695)
**Author:** [@rjbelden](https://forum.arduino.cc/u/rjbelden)\ **Replies:** 131\ **Last updated:** [June 18, 2026, 3:20pm UTC](https://forum.arduino.cc/t/mini-pro-overhearing-and-burning-out-when-connected-to-darlington-chip/1448695 "2026-06-18T15:20:52Z")
Over the last year Ive completed several projects connecting a mini pros (5v, 16) to a darlington, so I can use a common power approach and use the 5v directly. A few days ago, I tried his approach again and the mini pr… --- ## [Unable to Upload to Pro Mini using UNO](https://forum.arduino.cc/t/unable-to-upload-to-pro-mini-using-uno/1448205)
**Author:** [@STDummy](https://forum.arduino.cc/u/STDummy)\ **Replies:** 12\ **Last updated:** [June 13, 2026, 1:13pm UTC](https://forum.arduino.cc/t/unable-to-upload-to-pro-mini-using-uno/1448205 "2026-06-13T13:13:39Z")
I'm attempting to upload a sketch to a 5V ProMini using a UNO as ISP, but the sketch will not upload. The IDE output window states: Using port : COM8 Using programmer : arduino Setting baud rate : … --- ## [Arduino ZERO 3D model](https://forum.arduino.cc/t/arduino-zero-3d-model/1446150)
**Author:** [@dm7430](https://forum.arduino.cc/u/dm7430)\ **Replies:** 10\ **Last updated:** [May 31, 2026, 2:33pm UTC](https://forum.arduino.cc/t/arduino-zero-3d-model/1446150 "2026-05-31T14:33:50Z")
I'm starting to get into Arduino programming and have ideas for a first project. I'd like to start working on an enclosure to hold the Arduino ZERO, a 20x4 LCD display, some sensor modules and a battery holder. Does an… --- ## [Request: Arduino Yún original ART partition dump (Wi-Fi has no range)](https://forum.arduino.cc/t/request-arduino-yun-original-art-partition-dump-wi-fi-has-no-range/1445668)
**Author:** [@gonia\_ru](https://forum.arduino.cc/u/gonia_ru)\ **Replies:** 1\ **Last updated:** [May 25, 2026, 6:13pm UTC](https://forum.arduino.cc/t/request-arduino-yun-original-art-partition-dump-wi-fi-has-no-range/1445668 "2026-05-25T18:13:44Z")
Hi everyone, I am trying to recover the Wi-Fi on my original Arduino Yún (AR9331). My original art partition was lost. I successfully bypassed the MTD write lock using i\_want\_to\_brick\_my\_device=1 and flashed an ART dum… --- ## [Arduino YUN failed update](https://forum.arduino.cc/t/arduino-yun-failed-update/1441145)
**Author:** [@apiwebadm](https://forum.arduino.cc/u/apiwebadm)\ **Replies:** 2\ **Last updated:** [May 22, 2026, 9:18am UTC](https://forum.arduino.cc/t/arduino-yun-failed-update/1441145 "2026-05-22T09:18:52Z")
hi, i tried to update my YUN (rev1) and no it doesnt boot the linux. I can connect via usb but can´t via netwrork tft etc. so I can't downdrade the firmware as arduino.cc sugest. Either can't enter the u-boot interface … --- ## [Pro mini not able to upload](https://forum.arduino.cc/t/pro-mini-not-able-to-upload/1438200)
**Author:** [@bakedpotatolord2](https://forum.arduino.cc/u/bakedpotatolord2)\ **Replies:** 5\ **Last updated:** [April 2, 2026, 5:51pm UTC](https://forum.arduino.cc/t/pro-mini-not-able-to-upload/1438200 "2026-04-02T17:51:01Z")
I'm trying to program an arduino pro mini for an NRF remote , but it won't upload a sketch. I know that the programmer works, and I know it's the right voltage and speed (3.3v, 8Mhz). I tested it with another pro mini bo… --- ## [NeoPixel damaging Digital IOs?](https://forum.arduino.cc/t/neopixel-damaging-digital-ios/1433794)
**Author:** [@sniktaw](https://forum.arduino.cc/u/sniktaw)\ **Replies:** 15\ **Last updated:** [March 5, 2026, 3:12pm UTC](https://forum.arduino.cc/t/neopixel-damaging-digital-ios/1433794 "2026-03-05T15:12:41Z")
I have 2 new Pro Minis. 1 works as expected, 1 turns the NeoPixel LEDs all white. Same circuit, same code. I started off without using a level shifter and got all white LEDs so read the NeoPixel guide (I know, I know … --- ## [Arduino Yun update](https://forum.arduino.cc/t/arduino-yun-update/1430353)
**Author:** [@outbackhut](https://forum.arduino.cc/u/outbackhut)\ **Replies:** 1\ **Last updated:** [February 12, 2026, 1:57pm UTC](https://forum.arduino.cc/t/arduino-yun-update/1430353 "2026-02-12T13:57:35Z")
Has anyone had any success updating a Yun to the most modern OpenWRT? I have mine on OpenWRT 19.07.10. I want to get more modern if possible…. --- ## [Use of ICSP connection as SPI slave in a Arduino Zero sketch](https://forum.arduino.cc/t/use-of-icsp-connection-as-spi-slave-in-a-arduino-zero-sketch/1428868)
**Author:** [@darioia](https://forum.arduino.cc/u/darioia)\ **Replies:** 3\ **Last updated:** [February 4, 2026, 4:26pm UTC](https://forum.arduino.cc/t/use-of-icsp-connection-as-spi-slave-in-a-arduino-zero-sketch/1428868 "2026-02-04T16:26:55Z")
Hi all, I’d like to use the ICSP port as spi slave in a sketch, is it possible use it? I have downloaded a library (SercomSPISlave) released and tested on Zero, but seems not present the correct pins. It seems that the… --- ## [SPI SD Library on Arduino Zero](https://forum.arduino.cc/t/spi-sd-library-on-arduino-zero/1415796)
**Author:** [@swissmatt](https://forum.arduino.cc/u/swissmatt)\ **Replies:** 13\ **Last updated:** [November 28, 2025, 5:05pm UTC](https://forum.arduino.cc/t/spi-sd-library-on-arduino-zero/1415796 "2025-11-28T17:05:11Z")
On the Arduino Zero, the traditional SPI pins are on the ICSP connector. This \[I think\] means that most libraries which use SPI, and almost all the shields that use SPI will not work because SPI is expected to be on pins… --- ## [Block Between VIN & A0 on Arduino Zero Header](https://forum.arduino.cc/t/block-between-vin-a0-on-arduino-zero-header/1416191)
**Author:** [@photoelectron](https://forum.arduino.cc/u/photoelectron)\ **Replies:** 11\ **Last updated:** [November 25, 2025, 5:57am UTC](https://forum.arduino.cc/t/block-between-vin-a0-on-arduino-zero-header/1416191 "2025-11-25T05:57:20Z")
I have a breakout board with a row of pins which I thought would be Arduino compatible. The pins on the breakout board line up with the Power and Analog In female pin headers on your Arduino Zero or Uno (or so I thought)… --- ## [Arduino Leonardo port not detected, no serial communication](https://forum.arduino.cc/t/arduino-leonardo-port-not-detected-no-serial-communication/1414693)
**Author:** [@socimi](https://forum.arduino.cc/u/socimi)\ **Replies:** 27\ **Last updated:** [November 17, 2025, 5:36pm UTC](https://forum.arduino.cc/t/arduino-leonardo-port-not-detected-no-serial-communication/1414693 "2025-11-17T17:36:50Z")
Hello all, I am a novice with Arduino, having been thinkering with it for about two weeks only. I have a (genuine) Arduino Leonardo board, wich i've been working on for a few days, and it worked perfectly fine, but thi… --- ## [UART not working](https://forum.arduino.cc/t/uart-not-working/1413528)
**Author:** [@claudio\_s](https://forum.arduino.cc/u/claudio_s)\ **Replies:** 10\ **Last updated:** [November 11, 2025, 9:21pm UTC](https://forum.arduino.cc/t/uart-not-working/1413528 "2025-11-11T21:21:52Z")
Hi guys, I'm trying some Arduino Micro connected to a LoRa module and I've spent the last 2 days trying to make a simple task. This is the code void setup() { Serial.begin(9600); while (!Serial) {} } void loo… --- ## [Arduino Micro not being detected](https://forum.arduino.cc/t/arduino-micro-not-being-detected/1413406)
**Author:** [@ottoomio](https://forum.arduino.cc/u/ottoomio)\ **Replies:** 3\ **Last updated:** [November 10, 2025, 11:27am UTC](https://forum.arduino.cc/t/arduino-micro-not-being-detected/1413406 "2025-11-10T11:27:24Z")
Arduino Micro isn't being detected at all after aborting code upload from the IDE button. It powers on and reset resets it but it still doesnt detect it anymore. --- ## [Atsamd21g18a not recognized on USB](https://forum.arduino.cc/t/atsamd21g18a-not-recognized-on-usb/1411272)
**Author:** [@iguera](https://forum.arduino.cc/u/iguera)\ **Replies:** 3\ **Last updated:** [October 30, 2025, 6:19pm UTC](https://forum.arduino.cc/t/atsamd21g18a-not-recognized-on-usb/1411272 "2025-10-30T18:19:20Z")
I want to upload code in my new atsamd21g18 (custom board), but the pc dont recognize the usb port. Im using a Stlink-v2 and used Openocd to flash the bootloader from arduinozero From this link: Used this Adafruit tu… --- ## [Leonardo doesn't detected anymore](https://forum.arduino.cc/t/leonardo-doesnt-detected-anymore/1408199)
**Author:** [@mastakillaman](https://forum.arduino.cc/u/mastakillaman)\ **Replies:** 4\ **Last updated:** [October 3, 2025, 8:10am UTC](https://forum.arduino.cc/t/leonardo-doesnt-detected-anymore/1408199 "2025-10-03T08:10:28Z")
By some reason I can’t connect to my Leonardo on macbook. When I press “reboot” button I see the device is connected to usb in Arduino IDE in the dropdown (led is blinking on the board), but once it is rebooted it disap… --- ## [Use type-c to micro usb cable](https://forum.arduino.cc/t/use-type-c-to-micro-usb-cable/1407613)
**Author:** [@mastakillaman](https://forum.arduino.cc/u/mastakillaman)\ **Replies:** 3\ **Last updated:** [September 26, 2025, 10:04am UTC](https://forum.arduino.cc/t/use-type-c-to-micro-usb-cable/1407613 "2025-09-26T10:04:29Z")
I got type-c to usb micro cable and not sure if I can use it to connect arduino to my macbook and use as usb midi and don’t burn it. Can I do it or it will burn? Many thanks! --- ## [Arduino Leonardo. Using 0 an 1 digital pins](https://forum.arduino.cc/t/arduino-leonardo-using-0-an-1-digital-pins/1407039)
**Author:** [@mastakillaman](https://forum.arduino.cc/u/mastakillaman)\ **Replies:** 12\ **Last updated:** [September 21, 2025, 4:49pm UTC](https://forum.arduino.cc/t/arduino-leonardo-using-0-an-1-digital-pins/1407039 "2025-09-21T16:49:42Z")
Hello. Is it possible to use 0 and 1 pins for buttons? I found that if I use serial using I can’t use these pins, but it is possible to disconnect these pins every time I need to update code. But I use usbmidi, so arduin… --- ## [Introducing the Modernized Arduino Yun v2 Ecosystem!](https://forum.arduino.cc/t/introducing-the-modernized-arduino-yun-v2-ecosystem/1407013)
**Author:** [@isantolin](https://forum.arduino.cc/u/isantolin)\ **Replies:** 0\ **Last updated:** [September 20, 2025, 8:37pm UTC](https://forum.arduino.cc/t/introducing-the-modernized-arduino-yun-v2-ecosystem/1407013 "2025-09-20T20:37:36Z")
Over the past months, we have completely revamped the software stack for the Arduino Yun, focusing on robustness, interoperability, and seamless integration with modern IoT systems. This project is now more open, flexibl… --- ## [Arduino Leonardo Doesnt get detected by device manager](https://forum.arduino.cc/t/arduino-leonardo-doesnt-get-detected-by-device-manager/1405468)
**Author:** [@phiora](https://forum.arduino.cc/u/phiora)\ **Replies:** 6\ **Last updated:** [September 6, 2025, 12:57pm UTC](https://forum.arduino.cc/t/arduino-leonardo-doesnt-get-detected-by-device-manager/1405468 "2025-09-06T12:57:54Z")
Hello, When i plug my leonardo in to my pc it doesnt show up in device manager i tried everything, Another pc,another cable but nothing worked im worried that its not gonna work how do we fix it? --- ## [Mouse HID Descriptor for more than 3 mouse buttons](https://forum.arduino.cc/t/mouse-hid-descriptor-for-more-than-3-mouse-buttons/1389898)
**Author:** [@AnotherArduinoEnthusiast](https://forum.arduino.cc/u/AnotherArduinoEnthusiast)\ **Replies:** 1\ **Last updated:** [June 19, 2025, 7:42pm UTC](https://forum.arduino.cc/t/mouse-hid-descriptor-for-more-than-3-mouse-buttons/1389898 "2025-06-19T19:42:28Z")
I need to support more than 3 mouse buttons via the built-in Mouse HID for the Arduino Leonardo. I've taken the Mouse.cpp/h files and modified them to set the descriptor as follows: static const uint8\_t \_hidReportDescri… --- ## [Can I use unused special pins as Digital I/O pins](https://forum.arduino.cc/t/can-i-use-unused-special-pins-as-digital-i-o-pins/1388083)
**Author:** [@bengunn](https://forum.arduino.cc/u/bengunn)\ **Replies:** 6\ **Last updated:** [June 11, 2025, 7:26pm UTC](https://forum.arduino.cc/t/can-i-use-unused-special-pins-as-digital-i-o-pins/1388083 "2025-06-11T19:26:42Z")
I am about to use a Micro where I only use the Rx on Serial 1, so TX/D1 is not used, and only send on SPI, so CIPO/D14 is not used. My question is, can I use D1 and D14 as digital I/O pins? [Next page](https://forum.arduino.cc/c/official-hardware/classic/197.md?page=1)