Skip to content
OpenStick Community

HMUF02 (HMUF02-V05) Pinouts: EDL 9008 Test Points & 1.8V UART

The HMUF02 integrates its EDL recovery test points adjacent to the SIM tray and provides a physical SMD reset push button on the PCB.

PCB Test Point Map

Section titled “PCB Test Point Map”

Top / Component Side

Section titled “Top / Component Side”
   ┌─────────────────────────────────────────────────────────┐
   │ [USB-A]                                                 │
   │                                                         │
   │   [TX]  [RX]  [GND] (1.8V UART)                         │
   │                                                         │
   │        ┌─────────────────────────┐                      │
   │        │     MSM8916 SoC         │    [===] Reset Button│
   │        │     (under shield)      │          (or pinhole)│
   │        └─────────────────────────┘                      │
   │                                                         │
   │          (o) (o) <── EDL Test Pads                      │
   │                                                         │
   │        ┌─────────────────────────┐                      │
   │        │    Micro-SIM Tray       │    [Antenna Pigtail] │
   │        └─────────────────────────┘                      │
   └─────────────────────────────────────────────────────────┘

1. Entering Qualcomm EDL Mode (9008)

Section titled “1. Entering Qualcomm EDL Mode (9008)”

If your bootloader fails or you flash an incompatible kernel image, EDL mode provides full raw eMMC read/write recovery.

Video Walkthrough: Never Brick Your Modem (EDL Mode Hack)

Section titled “Video Walkthrough: Never Brick Your Modem (EDL Mode Hack)”

Watch this video guide by @glos-os demonstrating how to enter Qualcomm 9008 EDL mode on the HMUF02 using the reset pinhole or test pads and dump critical calibration partitions:

Method A: The Physical Reset Switch (On Select Batches)

Section titled “Method A: The Physical Reset Switch (On Select Batches)”
  1. Disconnect the HMUF02 from USB.
  2. Insert a paperclip into the Reset pinhole on the casing (or press the miniature SMD tactile switch on the board).
  3. While holding the button down, plug the dongle into a USB port.
  4. Release the button after 2 seconds.
  5. Check if the PC enumerates 05c6:9008 (EDL).

Method B: Tweezers on EDL Test Pads

Section titled “Method B: Tweezers on EDL Test Pads”
  1. If the reset button does not trigger EDL on your specific firmware version:
  2. Locate the two small circular gold test pads situated right next to the Micro-SIM tray.
  3. Short the two pads together with conductive metal tweezers.
  4. Insert the stick into the USB port, hold for 2 seconds, and release.
  5. Verify on Linux:
    Terminal window
    lsusb | grep 05c6:9008
    # Qualcomm, Inc. Gobi Wireless Modem (QDL mode)

2. Hardware UART Serial Console (1.8V)

Section titled “2. Hardware UART Serial Console (1.8V)”

The HMUF02 features 3 small unpopulated SMD solder pads along the edge near the USB-A connector.

Pin Connections

Section titled “Pin Connections”
HMUF02 Pad Direction USB-to-UART Adapter Pin
TX Output RX
RX Input TX
GND Ground GND (or USB metal shielding)

Serial Terminal Configuration

Section titled “Serial Terminal Configuration”
  • Baud rate: 115200
  • Data bits: 8
  • Parity: None
  • Stop bits: 1
  • Flow control: None

3. GPIO Pin Assignments

Section titled “3. GPIO Pin Assignments”

The HMUF02 uses the following Qualcomm PMIC and SoC GPIO connections:

Function Hardware GPIO Logic Level Description
Power / 4G LED GPIO 3 Active Low Lights up during cellular connection
Wi-Fi LED GPIO 1 Active High Controlled by WCN3620 driver trigger
SMS LED GPIO 2 Active High Flashes when SMS message is queued
Reset Key GPIO 107 Active Low (Pull-up) Linked to physical tactile button
SIM Hotplug GPIO 50 Pull-up Triggers SIM detection interrupt

Frequently Asked Questions — HMUF02 (HMUF02-V05)

Is the HMUF02-V05 board compatible with OpenStick Debian Linux?

Yes! Genuine HMUF02-V05 (and HMUF02-MB-V01/V02) boards powered by the Qualcomm MSM8916 (Snapdragon 410) with 4GB eMMC storage are fully supported by OpenStick Debian and lk2nd.

How do I check if my HMUF02 is genuine MSM8916 or an ASR1802 clone?

Open the shell to verify the HMUF02-V05 silkscreen and Qualcomm MSM8916 chip, or run adb shell getprop ro.board.platform to confirm it outputs msm8916 instead of asr1802 or zx297520.

👉 Ready to flash? Download the 1-Click OpenStick Debian Installer or browse Verified Store Links.