0

Fixing motherboard COM port dongles

mboardcom

So remember that Shuttle computer we got a few weeks ago? Finally had time to install it as our backup shipping station and we couldn’t get the scale to work (its a serial port device). Turns out the motherboard “COM port dongles” were wired for a different kind of motherboard! So if you ever decide to do this yourself, note that the dongles come with ‘alternating’ pins when they really should not be. Check your motherboard documentation to verify which you need, and then a quick soldering fix!


Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 13,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython 2019!

Have an amazing project to share? The Electronics Show and Tell with Google Hangouts On-Air is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/


Maker Business — A list of companies owned by Amazon. It’s big.

Wearables — Raid the kitchen

Electronics — Capacitor ESR

Biohacking — Vitamin-C + Gelatin for Accelerated Recovery

Python for Microcontrollers — Python snakes its way to the STM32, Serpente, and more!

Adafruit IoT Monthly — Adafruit IO Updates, RGB Stream Deck Message Panel, and more

Microsoft MakeCode — Welcome to the MakeCode Newsletter!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



5 Comments

  1. I had the exact same issue recently with a BioStar A760G M2+ AM2+ board.

    I chalked it up to being: a) I had a generic connector, and b) they probably sell a board specific version. I couldn’t find a board / mfr specific version, so I did just what you illustrate!

    Fortunately the manual usually provides the pinouts…

    Mike Y
    Dallas, Texas

  2. Difficult to see what the dongles are doing, I am thinking that they link the 9 pin header (10 with 1 NC) to the outside female connector.

    If so, perhaps it is best to make it clear that the photo you show is correct for your motherboard specifically…

    I use an Asus Motherboard and recently had to make up a similar cable to fix a Dreambox that I bricked. On my motherboard, the straight through arrangement is the correct version to use. Apparently there is not a standard serial pinout on motherboards.

  3. Don’t know ’bout all them new-fangled serial ports on motherboards but I definitely had IDE/Floppy/Game/Parallel/2xSerial ISA boards which had different wiring of the ten pin headers for the serial ports so the separate back-plates with 1×25-pin and 1×9-pin serials weren’t interchangeable.

  4. Motherboard and expansion board manufacturers (and anyone else that’s paying for labor) commonly(?) make their header pinouts line up so that IDC connectors on a ribbon cable will get the right signals on the right pins at the D connector. That uses the alternating conductor scheme from the Bad ribbon in the photo. My guess is Adafruit got a “free-range” motherboard, or one from a vendor who wants you to buy only their cables.

  5. Loved the economic evaluation of computer options. I just built a Celeron dual core for my daughter for less then 350, here in Brazil. My kids simply doesn’t need a core i7… in fact neither do I. My AMD Athlon 64 is beginning to feel slow, but will last until at least next year, when I’m getting a core 2 duo or an Athlon X2

Sorry, the comment form is closed at this time.