Project Log: Installing an LF Reader into a Dell Laptop

Here is a project I just completed.

I have an installed xEM and wanted to use it to login to my computer. Since it is an EM4100 it has a UID and I decided to try out the cheapo USB readers that can input as an HID (keyboard). It worked fairly well so I went to work installing it.

Parts:

  • Dell Wyse 5470 laptop
  • Cheapo RFID reader (~$12)
  • Old USB cable
  • Kaptop tape
  • Hot glue
  • Home wound ferrite core antenna (instructions on this forum somewhere)
  • Solder

Plan:

The keyboard rest is probably not going to be able to be read through, even though there is a huge empty spot for a smart card reader that isn’t installed. I figure the best bet is to use the ferrite core antenna I have, since I wound a bunch of them trying to get one just right for the ProxMark. Since the end of the antenna rod basically has to be touching skin to read, the antenna would stick out where the VGA port is, with the VGA port being removed (it is modular). The antenna would connect to a cheap USB reader which would be directly soldered to a free USB 2 port on the computer.

Issues:

The only real issue I faced was that there wasn’t enough room for the back cover to fit. There was a metal bracket installed for a laptop lock, and once I removed that it fit just fine.

End result:

Works perfectly.

Pics:

I don’t know how to upload pictures here, so here is an imgur album.













8 Likes

I edited your post and did that for you.

Here’s how

2 Likes

Thanks for the edit.

2 Likes

Oh, Nice work on the project.

Thanks for sharing :+1:

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I love projects like this

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Update:

Turns out something in the Dell hardware which makes the reader break when it falls asleep (probably relying on a single USB 3.1 hub which are notorious for not implementing backwards compatibility for low power devices properly). This makes it pretty difficult to use as a practical login method in a laptop, but I did figure out how to fix it.

If anyone runs into something similar there is simple software solution to get Windows to restart the RFID reader when it wakes from sleep.

  1. Open Task Scheduler

  2. Create a new task:

    • Name: “Restart RFID Reader After Sleep”
    • Run with highest privileges: Yes
    • Configure for: Windows 10 (or your OS version)
  3. Triggers:

    • New Trigger
    • Begin the task: On an event
    • Log: System
    • Source: Kernel-Power
    • Event ID: 42
  4. Actions:

    • New Action
    • Action: Start a program
    • Program/script: pnputil
    • Add arguments: /restart-device “YOUR_DEVICE_INSTANCE_ID”

    Replace YOUR_DEVICE_INSTANCE_ID with the actual ID. To find it:

    • Open Device Manager
    • Locate your RFID reader, called USB Input Device under the HID section
    • Right-click > Properties > Details
    • Property: Device instance path
    • Copy the value
  5. Settings:

    • Allow task to be run on demand: Yes

Now whenever the laptop wakes up the reader is restarted and will be useable.

4 Likes

Doesn’t windows have an obscure option somewhere in Device settings for “Do not allow windows to put this device to sleep” or something?

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Beautiful. All I did is duct taped a KBR1 to mine.

3 Likes

That didn’t work because it was the internal hub, not the device, that was the problem, and turning off power management for that would have some much bigger negative effects.