FOSS dev, self-hosting fan, Matrix, degoogling, small tech, indie tech, friendly tech for families and schools. Let's own our own identity & data.

This article is about one particular step of the procedure for “flashing” a new android-compatible operating system onto a Samsung device to create a Freedom-Respecting Smart Phone or Tablet.


This is about flashing a custom operating system ROM in a Samsung Android device using the tool named Heimdall.

We may encounter a failure mode in which heimdall detect succeeds but heimdall flash and heimdall print-pit both fail, printing this:

Initialising connection...
Detecting device...
Claiming interface...
Setting up interface...

Initialising protocol...
ERROR: Failed to send handshake!ERROR: Protocol initialisation failed!

Releasing device interface...

Additional diagnostics if we give the --verbose option:

"ERROR: libusb error -7 whilst sending bulk transfer"

(This message is repeated several times, before the final failure.)

Errors like this have been reported many times: e.g. here and duplicates, here, here

Here are two scenarios in which this error can occur.

Scenario 1: Only The First Heimdall (Flash, Print-Pit) Command Works

It is reported that on some devices, including Samsung, only one Heimdall command can be given in the bootloader mode. Further attempts fail. Rebooting is required before another command can succeed.

(In this description, “heimdall flash” and “heimdall print-pit” count towards the limit of one command, while “heimdall detect” doesn't count towards the limit and can be used freely.)

This may be a real limitation of the devices, or it may be that using Heimdall's options “—no-reboot” (on each command) and “—resume” (since 1.4.0, on subsequent commands) options may overcome this. I do not have such a device and did not find conclusive evidence in my search for information.

Scenario 2: Every Heimdall (Flash, Print-Pit) Command Fails

This happens only when running Heimdall on certain linux distributions, notably Ubuntu.

Some people fixed this in their forks of Heimdall, e.g. Jesse Chan's fix is in Grimler's version of Heimdall and in several other forks. (This fix works by resetting the USB device on the Linux end.)

My suggestion: build and use Grimler's Heimdall. I explain a bit about Heimdall and how to build and use it in my article Odin and Heimdall: Free Your Samsung Android .

Scenario 3: Heimdall With Resume Option Fails First Time

If the first Heimdall command after booting into download mode is given the '—resume' option, Heimdall fails for me (on Ubuntu 22.04) like this, even when using a version with the Scenario 2 bug fixed:

$ heimdall print-pit --resume --no-reboot --verbose
Beginning session...
ERROR: libusb error -7 whilst sending bulk transfer. Retrying...
ERROR: Failed to begin session!
Releasing device interface...

From what I can tell, this seems to be expected, and so a usage error. The '—resume' option should not be used on the first command.

#fossGadgets #android #degoogled #lineageOS #eOS


This is about buying a Samsung Android tablet and replacing the privacy-invading proprietary Google and Samsung software with privacy-respecting Freedom Software: “degoogling” for short.

Why? In “The Problem” section below, we take a look back at how much we're giving up when we accept Google's and Samsung's terms.

I would like ordinary people, with a little technical skill, to be able to do this. The process unfortunately is currently far too difficult, especially so on Samsung devices.

My goals:

  • Install a privacy-preserving freedom-software operating system on my tablet
  • Make it easier for others to do the same

The cap leaks, from new, so unsuitable for carrying in a school bag. Now the bottom is cracked and leaking too, as soon as dropped from ~1m carrying heigh on its first morning going to school. Pointless.

We're better off just re-using any ordinary “disposable” drinks bottle.

600 ml size — leaks, cracks, pointless 380 ml size — also leaks

Both bought from Tesco, 2024-05-15.

POSSE — posted reviews on tesco.com

  • 2024-05-15 First review (2 star: cap leaks).
  • 2024-05-16 Second review (1 star: cap leaks, cracked on impact, as above).

#POSSE #review


The PineTime (open-source hardware and software) smart watch strap fits with a 20 mm pin connector, which is a common standard fitting. However, not all 20 mm straps fit, because of the shape of the housing around it.

I bought a cheap silicone 20mm watch strap. Its ends were 20mm wide but too fat to fit in the PineTime. I sliced off some silicone with a sharp craft knife. Now it fits. Not perfectly beautiful but unobtrusive and neat enough.

2024-04-19-10-28-12-585.jpg 2024-04-19-10-41-51-126.jpg 2024-04-19-10-56-59-742.jpg

#PineTime #openHardware


Completing This Phase

This is the last week of my funding on Moderator Tools for PubHubs. It has been a pleasure working with the PubHubs team. The time seems to go quickly.

Over the last few weeks I have been documenting everything about the Moderator Tools for PubHubs project on my dedicated web site, https://www.ph.trax.im/.

To summarise, these are the main work areas in this project, linking to their web site sections:

  1. Civilised Discourse

    • Researching best practices to inform the longer term design of PubHubs moderation facilities.
  2. Disclosure of Identity Attributes

    • Building a moderation tool specific to PubHubs' special features.
  3. Draupnir for PubHubs

    • Adapting the best existing moderation tool from the regular Matrix ecosystem (Draupnir), evaluating and extending it.

An idea for explaining Matrix: it's hi-fi separates vs. a mini-hi-fi.


We bought a solar panel installation and now generate more electricity than we use... sometimes. In principle, we can sell that electricity back to an energy company. In practice there are two caveats. The first is well known: the rate they pay us is only a small fraction of the price they charge us for electricity. The second problem I did not appreciate in advance: the hassle of applying for and setting up the payment scheme.


This is my POSSE copy of the announcement posted in This Week in Matrix (TWIM) 2024-03-29.


This is my POSSE copy of the announcement posted in This Week in Matrix (TWIM) 2024-03-29.