From a83ca982cf65b992e21d7d3838322755a9fa6b75 Mon Sep 17 00:00:00 2001
From: pstruebi <struebin.patrick@gmail.com>
Date: Wed, 5 Nov 2025 18:06:53 +0100
Subject: [PATCH] add devicetree overlay for i2s and asound.conf

---
 .gitignore                                    |  3 ++
 src/misc/asound.conf                          | 39 +++++++++++++++++++
 src/misc/install_asoundconf.sh                |  1 +
 src/misc/pcm1862-i2s.dts                      | 10 +++--
 .../{list_pw_nodes.py => list_sd_nodes.py}    |  0
 5 files changed, 50 insertions(+), 3 deletions(-)
 create mode 100644 src/misc/asound.conf
 create mode 100644 src/misc/install_asoundconf.sh
 rename src/scripts/{list_pw_nodes.py => list_sd_nodes.py} (100%)

diff --git a/.gitignore b/.gitignore
index cd9aa4c..1170d49 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,3 +46,6 @@ src/auracast/server/certs/ca/ca_cert.srl
 src/auracast/server/credentials.json
 pcm1862-i2s.dtbo
 test.wav
+both.wav
+vin1.wav
+vin2.wav
diff --git a/src/misc/asound.conf b/src/misc/asound.conf
new file mode 100644
index 0000000..43e72eb
--- /dev/null
+++ b/src/misc/asound.conf
@@ -0,0 +1,39 @@
+# --- raw HW by card ID (no sharing) ---
+pcm.adc_hw_stereo {
+  type hw
+  card "i2s"   # from `arecord -l`: card 2: i2s [pcm1862 on i2s]
+  device 0
+}
+
+# --- mono splits (do the routing here) ---
+pcm.adc_in1 {
+  type route
+  slave.pcm "adc_hw_stereo"
+  slave.channels 2
+  ttable.0.0 1.0   # left -> mono
+  ttable.1.0 0.0
+}
+
+pcm.adc_in2 {
+  type route
+  slave.pcm "adc_hw_stereo"
+  slave.channels 2
+  ttable.0.0 0.0
+  ttable.1.0 1.0   # right -> mono
+}
+
+# --- diagnostics: exact slot taps (bypass any sharing/conversion) ---
+pcm.adc_ch0 {
+  type route
+  slave.pcm "adc_hw_stereo"
+  slave.channels 2
+  ttable.0.0 1.0
+  ttable.1.0 0.0
+}
+pcm.adc_ch1 {
+  type route
+  slave.pcm "adc_hw_stereo"
+  slave.channels 2
+  ttable.0.0 0.0
+  ttable.1.0 1.0
+}
diff --git a/src/misc/install_asoundconf.sh b/src/misc/install_asoundconf.sh
new file mode 100644
index 0000000..fce13fc
--- /dev/null
+++ b/src/misc/install_asoundconf.sh
@@ -0,0 +1 @@
+sudo cp src/misc/asound.conf /etc/asound.conf
\ No newline at end of file
diff --git a/src/misc/pcm1862-i2s.dts b/src/misc/pcm1862-i2s.dts
index da80468..7c2f30d 100644
--- a/src/misc/pcm1862-i2s.dts
+++ b/src/misc/pcm1862-i2s.dts
@@ -7,24 +7,28 @@
     /* Enable the I²S controller */
     fragment@0 {
         target = <&i2s>;
-        __overlay__ { status = "okay"; };
+        __overlay__ {
+            status = "okay";
+        };
     };
 
-    /* PCM1862 on I2C1 at 0x4a */
+    /* PCM1862 on I2C1 at 0x4a (change if your bus/address differ) */
     fragment@1 {
         target = <&i2c1>;
         __overlay__ {
             #address-cells = <1>;
             #size-cells = <0>;
+
             pcm1862: adc@4a {
                 compatible = "ti,pcm1862";
                 reg = <0x4a>;
                 #sound-dai-cells = <0>;
+                /* Rails are hard-powered on your board, so no regulators here */
             };
         };
     };
 
-    /* Link bcm2835-i2s <-> pcm1862 with simple-audio-card */
+    /* Link bcm2835-i2s <-> pcm1862 via simple-audio-card */
     fragment@2 {
         target-path = "/";
         __overlay__ {
diff --git a/src/scripts/list_pw_nodes.py b/src/scripts/list_sd_nodes.py
similarity index 100%
rename from src/scripts/list_pw_nodes.py
rename to src/scripts/list_sd_nodes.py