From 13a89d73116a5fad57ca0fefbdf292e0978bf0ef Mon Sep 17 00:00:00 2001
From: helgie22 <helgie22@ru.is>
Date: Thu, 15 Oct 2026 15:29:08 +0000
Subject: [PATCH] =?UTF-8?q?ger=C3=B0i=20breytingar=20pi=20megin=20og=20?=
 =?UTF-8?q?=C3=BEarf=20a=C3=B0=20pusha=20fyrir=20t=C3=B6lvuna?=
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---
 pi/can_up.sh                        |  6 +++---
 platformio.ini                      |  6 ++++++
 src/CAN_FRAME_TEST.c                | 14 ++++++++------
 src/main.c                          |  3 +++
 zephyr/boards/nucleo_l432kc.overlay |  4 ++++
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/pi/can_up.sh b/pi/can_up.sh
index 12f989f..5381813 100755
--- a/pi/can_up.sh
+++ b/pi/can_up.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
-# Brings up can0 at the same bitrate as the Nucleo (CAN_BITRATE in src/can_send_test.c).
-# Usage: ./can_up.sh [bitrate]   (default 250000)
-BITRATE=${1:-250000}
+# Brings up can0 at the same bitrate as the Nucleo (125000 in src/CAN_FRAME_TEST.c and src/can_send_test.c).
+# Usage: ./can_up.sh [bitrate]   (default 125000)
+BITRATE=${1:-125000}
 
 sudo ip link set can0 down 2>/dev/null
 sudo ip link set can0 up type can bitrate "$BITRATE"
diff --git a/platformio.ini b/platformio.ini
index 75ecb08..e2183d5 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -27,3 +27,9 @@ upload_flags =
 [env:can_test]
 extends = env:nucleo_l432kc
 build_flags = -D CAN_SEND_TEST=1
+
+; L4.4 example (src/CAN_FRAME_TEST.c) instead of the motor app.
+; Build/upload: pio run -e can_frame_test -t upload
+[env:can_frame_test]
+extends = env:nucleo_l432kc
+build_flags = -D CAN_FRAME_TEST=1
diff --git a/src/CAN_FRAME_TEST.c b/src/CAN_FRAME_TEST.c
index b579da6..bca3a33 100644
--- a/src/CAN_FRAME_TEST.c
+++ b/src/CAN_FRAME_TEST.c
@@ -7,25 +7,27 @@
 /* Devicetree node selected by zephyr,canbus in the overlay */
 #define CANBUS_NODE DT_CHOSEN(zephyr_canbus)
 
-int main(void)
+// L4.4 example. Built only with the can_frame_test environment
+// (-D CAN_FRAME_TEST=1); main() in main.c calls this function.
+void can_frame_test_main(void)
 {
     const struct device *dev = DEVICE_DT_GET(CANBUS_NODE);
 
     if (!device_is_ready(dev)) {
         printk("CAN device not ready\n");
-        return 0;
+        return;
     }
 
     int err = can_set_bitrate(dev, 125000);
     if (err != 0) {
         printk("Error setting CAN bitrate (err %d)\n", err);
-        return 0;
+        return;
     }
 
     err = can_start(dev);
     if (err != 0) {
         printk("Error starting CAN controller (err %d)\n", err);
-        return 0;
+        return;
     }
 
     struct can_frame frame = {
@@ -41,7 +43,7 @@ int main(void)
         err = can_send(dev, &frame, K_MSEC(100), NULL, NULL);
         if (err != 0) {
             printk("Sending failed (err %d)\n", err);
-            return 0;
+            return;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/main.c b/src/main.c
index ecdd481..cc5c770 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,11 +2,14 @@
 
 void motor_application_main(void);
 void can_send_test_main(void);
+void can_frame_test_main(void);
 
 int main(void)
 {
 #if CAN_SEND_TEST
     can_send_test_main();
+#elif CAN_FRAME_TEST
+    can_frame_test_main();
 #else
     motor_application_main();
 #endif
diff --git a/zephyr/boards/nucleo_l432kc.overlay b/zephyr/boards/nucleo_l432kc.overlay
index e102e8e..c38471a 100644
--- a/zephyr/boards/nucleo_l432kc.overlay
+++ b/zephyr/boards/nucleo_l432kc.overlay
@@ -3,6 +3,10 @@
 #include <zephyr/dt-bindings/pwm/stm32_pwm.h>
 
 / {
+    chosen {
+        zephyr,canbus = &can1;
+    };
+
     aliases {
         encoder-c1 = &encoder_c1;
         encoder-c2 = &encoder_c2;