Notebook

Neovim and Rustaceanvim With Esp Toolchain

Sat, 29 Aug 2026 14:28:29 +0100

I was trying to get cargo to use the custom esp toolchain from Espressif, but use stable for rust-analyzer because the esp toolchain does not include a rust-analyzer component.

Neovim has a built-in option to load user-defined config at the project level called excr, which can be enabled with:

vim.o.exrc = true -- enable project local config

With this enabled, the following .nvim.lua will merge the global configuration I have set for vim.g.rustaceanvim (and this is helpful because I have settings for use with the bacon-lsp as well):

ESP32-C5 Programmable Usb

Sun, 23 Aug 2026 13:04:17 +0100

TL;DR: it can’t be done.

The USB peripheral on ESP32-C5 is non-programmable and only supports serial/JTAG (unless they release a new MCU).

Adding Environment Variables to Linux GUI Apps

Mon, 17 Aug 2026 21:37:22 +0100

Find the app your looking for:

sudo find / -type f -iname "*myapp*"

Edit the file:

nvim /usr/share/applications/org.myapp.MyApp.desktop

You’ll want to look for the Exec key, and prepend the env vars to the app command:

Exec=env MY_ENV_VAR=hello my-app-cmd %U

Trouble.nvim Filtering by Lsp

Sun, 09 Aug 2026 16:58:13 +0100

Filtering by LSP aka “source”

I like cSpell, but I don’t need a spell checker in my trouble.nvim diagnostics window. This can also be used for other LSPs/sources, but cSpell is the only LSP I want to keep around, just not when I toggle trouble.nvim:

{
 "folke/trouble.nvim",
 opts = {
 modes = {
 diagnostics = {
 filter = function(items)
 return vim.tbl_filter(function(item)
 local source = item["item.source"] or (item.item and item.item.source)
 return not (source and string.find(string.lower(source), "cspell", 1, true))
 end, items)
 end,
 },
 },
 }
}

ESP32, Embassy & Sockets

Sun, 09 Aug 2026 12:02:50 +0100

The Problem

I was running a webserver (picoserve), but I was only able to run one worker; somewhere in the picoserve code I was running into a panic from SocketSet add function, specifically this panic:

match &mut self.sockets {
 ManagedSlice::Borrowed(_) => panic!("adding a socket to a full SocketSet"),
 #[cfg(feature = "alloc")]
 ManagedSlice::Owned(sockets) => {
 sockets.push(SocketStorage { inner: None });
 let index = sockets.len() - 1;
 put(index, &mut sockets[index], socket)
 }
}

The problem, I eventually figured out, was that the network stack created with embassy-net was being initialized with 3 sockets: one for DHCP, one for DNS, and one for the rest of the code.

Lily T-Dongle S3 SD Card Pins

Sun, 19 Jul 2026 10:28:54 +0100

SD Card pin numbers for use with SPI

LilyGo Pin Name	GPIO #	SPI
SDMMC_D0	14	MISO
SDMMC_D1	17
SDMMC_D2	21
SDMMC_D3	18	CS
SDMMC_CLK	12	SCK
SDMMC_CMD	16	MOSI

Example

let spi_bus = Spi::new(
 peripherals.SPI2,
 spi::master::Config::default()
 .with_frequency(Rate::from_khz(400))
 .with_mode(spi::Mode::_0),
)
.unwrap()
.with_sck(peripherals.GPIO12) // clk
.with_mosi(peripherals.GPIO16) // cmd
.with_miso(peripherals.GPIO14) // d0
.into_async();

let sd_cs = Output::new(
 peripherals.GPIO18, // d3
 Level::High,
 OutputConfig::default().with_pull(Pull::Up),
);
let spi_dev = ExclusiveDevice::new(spi_bus, sd_cs, Delay).unwrap();
let sdcard = SdCard::new(spi_dev, Delay);

Hyprctl Moving Workspace Between Monitors

Thu, 25 Jun 2026 09:48:06 +0100

Hyprland recently migrated to lua, and this changed the inputs hyprctl required, so this is just a quick note about how to move workspaces between monitors if you have more than one.

The old command:

hyprctl dispatch moveworkspacetomonitor 1 1

New:

hyprctl dispatch 'hl.dsp.workspace.move({ workspace = 2, monitor = 1 })'

Dispatcher documentation

Flashing ESP32 Mini SD Card

Sun, 21 Jun 2026 18:40:16 +0100

For most ESP32 projects, a microSD card should be formatted to FAT32.

FAT32 only supports microSD cards up to 32GB.

# find the sd card with lsblk, then unmount it
sudo umount /dev/mmcblk0

# format in fat32 command
sudo mkfs.vfat -F32 /dev/mmcblk0

Serial Console in the Terminal

Thu, 11 Jun 2026 10:42:43 +0100

Instructions on how to connect to a device over serial USB port in the terminal on Arch with either minicom or tio.

Beforehand, ensure your user is in these groups (if adding, reboot machine).
```
# adding your user to these groups
sudo usermod -aG dialout tty uucp
```

With minicom

Install the minicom serial communication program.
```
sudo pacman -Sy minicom
```
Connect to device over serial comms (here it is at /dev/ttyUSB0).

OpenVPN on Arch

Tue, 09 Jun 2026 12:26:29 +0100

Import using systemctl

Copy OpenVPN client file to /etc directory:

sudo cp client.ovpn /etc/openvpn/client/myvpnconf.conf

Systemctl’s enable command turns on the service on boot, the --now flag also starts the service immediately:

# note the filename after @
systemctl enable --now openvpn-client@myvpnconf.service

This will start the VPN service with that configuration on boot, but this won’t integrate with networkmanager.

Integrating VPN connections with networkmanager

Disable the original systemctl service (if added previously)

systemctl disable --now openvpn-client@myvpnconf.service

Import OpenVPN connection

nmcli connection import type openvpn file myvpnconf.ovpn

Edit the connection to add username & password

nmcli connection modify myvpnconf \
 +vpn.data "connection-type=password-tls, username=$USERNAME" \
 vpn.user-name $USERNAME \
 +vpn.secrets "password=$PASSWORD"

Automatically connect to VPN

List connections

nmcli connection

NAME UUID TYPE DEVICE
zrh-003 d46e4a92-778e-4792-b085-e1f638ecb8e3 vpn enp1s0
enp1s0 1715b889-3c47-3e21-a86f-94ce207297a9 ethernet enp1s0
tun0 7405f329-255d-4b50-b98d-c2e865a443a4 tun tun0

Edit connection by adding the VPN UUID

# note if device name doesn't work use the UUID of the connection (not the VPN)
nmcli c edit enp1s0

nmcli> set connection.secondaries d46e4a92-778e-4792-b085-e1f638ecb8e3
nmcli> save persistent
Connection 'enp1s0' (1715b889-3c47-3e21-a86f-94ce207297a9) successfully updated.

Connecting to ESP32

Tue, 09 Jun 2026 08:45:33 +0100

Note

The hardware in this example is the ESP32-C3-DevKit-RUST-1 on Arch

Serial Port Access on Arch

Sat, 30 May 2026 09:35:24 +0100

For access to microcontrollers, such as the ESP32, permissions are required to enable flashing devices etc. If having issues, but seeing the port connected, check the port first (in my example the port was /dev/ttyACM0):

ls -l /dev/ttyACM0
crw-rw---- 1 root uucp 166, 0 May 27 21:05 /dev/ttyACM0

Notice the group uucp has access, we just need to add ourselves to it.

sudo usermod -aG uucp $USER

A restart may be required for this to take effect.