Dan Drown

SSH single-sign on

I was looking for a way to deal with ssh/sudo authentication between multiple clients and multiple devices. I wanted something with a balance between convenience and security.

Mounting a dedicated disk in WSL2

In WSL2, the default disks are virtual. Microsoft has recently added support for mapping physical disks to your WSL2 VM. I was running low on space my C: drive, so I wanted to move some of my WSL2 data to a dedicated Linux drive.

Bluetooth Low Energy sensor, part 2

To continue from part 1 [https://blog.dan.drown.org/bluetooth-low-energy-sensor/]: I want a wireless sensor that will last more than a month on 2x rechargeable AA or AAA batteries. Some ideas I have for what I could do with such a sensor: * indoor/outdoor temperature/humidity sensor * garage door

Bluetooth Low Energy sensor

I have some ideas for a low power wireless sensor. I want something that will last more than a month on 2x rechargeable AA or AAA batteries. I first tried an esp8266 and then an esp32, but the boards I have all use 3-7mA in "deep sleep". This

Replacing the WSL Kernel

Backstory I had a dual boot Windows/Fedora machine, and I wanted to be able to run the Fedora install as a VM inside WSL. To do this, I needed the physical disk accessible from the WSL kernel. Since the WSL kernel has no access to physical hardware like that,

Teensy 4.1 ethernet

I'm a fan of the Teensy [https://www.pjrc.com/teensy/] line of microcontrollers. I have a whole pile of them for various projects. When I saw that 4.1 was combining a 600MHz processor, 1MB ram, 8MB flash, and ethernet with ieee1588/ptp, I was excited. The

Embedded NTP Server

Now that I got the results I wanted from my embedded NTP client [https://blog.dan.drown.org/embedded-ntp-client-ntp-interleaved-mode-part-5/], I wanted to convert it to an NTP server. I also wanted it to support interleaved NTP [https://tools.ietf.org/html/draft-ietf-ntp-interleaved-modes-03] mode, so it could have hardware timestamps for

Embedded NTP client/NTP interleaved mode, part 5

I'll test what happens when I plug my embedded NTP client directly into my NTP servers, bypassing the Ethernet switch. This ends my long running embedded NTP client series. The systems involved Embedded NTP client (Archmax): Part 4 [https://blog.dan.drown.org/embedded-ntp-client-ntp-interleaved-mode-part-4/], Part 3 [https://blog.

Embedded NTP client/NTP interleaved mode, part 4

Part 3 [https://blog.dan.drown.org/embedded-ntp-client-ntp-interleaved-mode-part-3/] ended with an unexplained 3us offset, this post will reduce that. Verifying PTP clock sync I wanted to measure the NTP client's PTP clock sync externally. The PTP peripheral has the option to output a PPS that I can compare

STM32MP1 NTP server, part 3

Previous posts: part 1 [https://blog.dan.drown.org/stm32mp1-ntp-server/], part 2 [https://blog.dan.drown.org/stm32mp1-ntp-server-part-2/], NTP client [https://blog.dan.drown.org/embedded-ntp-client-ntp-interleaved-mode-part-3/] The NTP client confirmed that there was a 943ns difference between my two NTP servers. Now, to investigate where it is coming from. Changes