From 5c964b88309d26fbdadbf06658418fad3b6446ea Mon Sep 17 00:00:00 2001
From: Brad Barnett <127794626+bdbarnett@users.noreply.github.com>
Date: Mon, 5 Oct 2026 19:56:17 -0500
Subject: [PATCH] cast README: the firmware comes from build_mp.py now, not a
 board dir

---
 lib/examples/cast/README.md | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/examples/cast/README.md b/lib/examples/cast/README.md
index bebdcc45e..d130c2f42 100644
--- a/lib/examples/cast/README.md
+++ b/lib/examples/cast/README.md
@@ -15,9 +15,10 @@ the room. Over Wi-Fi, it can:
   shows the house's sensors on the P4. One button puts the whole panel on the
   TV.
 
-It needs the P4 firmware that carries `castif`, the board's default build in
-micropython-pydevices (`boards/esp32/WAVESHARE_ESP32_P4_PANEL`). Anything
-else lacks the H.264 encoder.
+It needs P4 firmware that carries `castif`, which any micropython-pydevices
+build with `--modules all` (or one naming `castif`) does; the command for each
+P4 is in its [newcomer's guide](https://github.com/PyDevices/micropython-pydevices/blob/main/docs/newcomers.md#boards-we-build-for).
+Anything else lacks the H.264 encoder.
 
 ## Try it