add flash app to flake

README.md

@@ -1,10 +1,10 @@
 # Little Buddy
 
-Firmware for the [PineBuds Pro](https://wiki.pine64.org/wiki/PineBuds_Pro). Hopefully.
+Firmware for the [PineBuds Pro](https://wiki.pine64.org/wiki/PineBuds_Pro).
 
-> **WARNING**: use at your own risk; this is currently worse than the factory default
+> **NOTE**: currently lacking functionality found in the factory default firmware (mainly, ANC)
 
-The following button taps/hold actions are currently mapped:
+The following button actions are mapped:
 
 | taps   | single bud     | left           | right       |
 | ------ | -------------- | -------------- | ----------- |
@@ -16,14 +16,13 @@ The following button taps/hold actions are currently mapped:
 
 ## install
 
-Download the latest [release](https://github.com/hall/little-buddy/releases).
+Download the latest [release](https://github.com/hall/little-buddy/releases) then flash both earbuds with
 
-Flash both earbuds with [`bestool`](https://github.com/Ralim/bestool):
+```sh
+nix run 'github:hall/little-buddy#flash' little-buddy-*.bin
+```
 
-    bestool write-image --port /dev/ttyACM0 little-buddy-*.bin
-    bestool write-image --port /dev/ttyACM1 little-buddy-*.bin
-
-> **NOTE**: if you have [nix](https://nixos.org/download.html) installed, you can use `nix run 'github:hall/little-buddy#bestool'` instead of building and installing it yourself
+> **NOTE**: if you don't want to use [nix](https://nixos.org/download.html), you can use [`bestool`](https://github.com/Ralim/bestool) directly
 
 ## languages
 
@@ -43,12 +42,12 @@ The following languages of audio alerts are currently supported:
 | русский   | Russian     | ru   |
 | 中国人    | Chinese     | zh   |
 
-As they are autogenerated, new languages are both easy to add and likely to have inconsistencies.
-Feel free to open an issue in either case.
+> **NOTE**: as they are autogenerated, new languages are both easy to add and likely to have inconsistencies; feel free to open an issue in either case.
+
 ## attribution
 
 Thus far, I've written almost none of this.
-All credit goes to the original authors.
+Credit goes to the original authors.
 
 ### name
 

flake.nix

@@ -15,6 +15,17 @@
         let pkgs = inputs.nixpkgs.legacyPackages.${system}; in
         {
           apps = {
+            flash = inputs.utils.lib.mkApp {
+              drv = pkgs.writeShellScriptBin "tts" ''
+                # should correctly identify the pinebuds
+                id=/dev/serial/by-id/usb-wch.cn_USB_Dual_Serial_0123456789-if
+                for i in 00 02; do
+                  # use the given file or a default
+                  [ $# -eq 1 ] && bin=$1 || bin=result/little-buddy-*-''${LANGUAGE:-en}.bin
+                  ${self.packages.${system}.bestool}/bin/bestool write-image --port $id$i $bin 
+                done
+              '';
+            };
             tts = inputs.utils.lib.mkApp {
               drv = pkgs.writeShellScriptBin "tts" ''
                 LANGUAGE=$1