diff --git a/camera_example/camera.cpp b/camera_example/camera.cpp
index 62e80f5..4ca4664 100644
--- a/camera_example/camera.cpp
+++ b/camera_example/camera.cpp
@@ -168,6 +168,7 @@ void processRequest(Request *request)
 int main()
 {
     std::signal(SIGPIPE, SIG_IGN);
+    std::signal(SIGINT,  [](int) { loop.exit(0); });
     std::thread(serverThread).detach();
 
     auto cm = std::make_unique<CameraManager>();
diff --git a/chip_test_example/Makefile b/chip_test_example/Makefile
new file mode 100644
index 0000000..0809bcc
--- /dev/null
+++ b/chip_test_example/Makefile
@@ -0,0 +1,28 @@
+# Build on device:
+#   apt install g++
+#   make
+# All deps (spidev, gpiochip, i2c-dev, termios) are kernel headers — no apt libs needed.
+
+CXX      ?= g++
+CXXFLAGS ?= -O2 -std=c++17 -Wall -Wextra
+
+TARGETS   = lora_tx lora_rx imu_test gps_test
+
+all: $(TARGETS)
+
+lora_tx: lora_tx.cpp lr1121_malnus.hpp
+	$(CXX) $(CXXFLAGS) $< -lpthread -o $@
+
+lora_rx: lora_rx.cpp lr1121_malnus.hpp
+	$(CXX) $(CXXFLAGS) $< -lpthread -o $@
+
+imu_test: imu_test.cpp icm20948.hpp
+	$(CXX) $(CXXFLAGS) $< -lpthread -o $@
+
+gps_test: gps_test.cpp gps.hpp
+	$(CXX) $(CXXFLAGS) $< -o $@
+
+clean:
+	rm -f $(TARGETS)
+
+.PHONY: all clean
diff --git a/chip_test_example/README.md b/chip_test_example/README.md
index 79de62d..7a86aa0 100644
--- a/chip_test_example/README.md
+++ b/chip_test_example/README.md
@@ -3,24 +3,32 @@
 Tests for LR1121 LoRa, ICM-20948 IMU, u-blox GPS on Raspberry Pi Zero W 2.
 Header-only drivers, kernel ioctls, no external libs.
 
+Driver: `lr1121_malnus.hpp` — crystal oscillator, RF switch via DIO5/DIO6.
+
 ---
 
 ## Wiring
 
 ### LR1121 (SPI0)
 
-| Module | Pi GPIO | Pi pin |
-|--------|---------|--------|
-| SCK    | GPIO11  | 23 |
-| MOSI   | GPIO10  | 19 |
-| MISO   | GPIO9   | 21 |
-| NSS    | GPIO8   | 24 |
-| BUSY   | GPIO24  | 18 |
-| NRESET | GPIO25  | 22 |
-| DIO9   | GPIO4   | 7  |
-| DIO8   | GPIO23  | 16 |
+| Module  | Pi GPIO | Pi pin |
+|---------|---------|--------|
+| SCK     | GPIO11  | 23 |
+| MOSI    | GPIO10  | 19 |
+| MISO    | GPIO9   | 21 |
+| NSS     | GPIO8   | 24 |
+| BUSY    | GPIO24  | 18 |
+| NRESET  | GPIO25  | 22 |
+| DIO5    | —       | chip-driven RF switch (RFSW0) |
+| DIO6    | —       | chip-driven RF switch (RFSW1) |
+| DIO9    | GPIO4   | 7  |
+| DIO8    | GPIO23  | 16 |
 
-Enable: `sudo raspi-config` → Interfaces → SPI → Yes → reboot
+DIO5 and DIO6 are driven directly by the LR1121 — they go to your module's RF
+switch and do not connect to the Pi. The driver configures them automatically
+via `SetDioAsRfSwitch`: HIGH on DIO5 in RX, HIGH on DIO6 in TX, both LOW in standby.
+
+Enable SPI: `sudo raspi-config` → Interfaces → SPI → Yes → reboot
 
 ### ICM-20948 (I2C1)
 
@@ -63,28 +71,29 @@ sudo ./imu_test -v
 ## LoRa debug
 
 ```sh
-ls /dev/spidev0.0         # SPI on?
+ls /dev/spidev0.0         # SPI enabled?
 sudo ./lora_rx -v --433   # step labels show exactly which command hangs
 ```
 
-If it hangs at `Calibrate` — that's a TCXO config issue. Try in order:
+If it hangs at `Calibrate` — the chip isn't responding over SPI at all.
+Check wiring, CS, and that SPI is enabled. The crystal needs no tuning.
 
-```sh
-sudo ./lora_rx -v --433 --tcxo-none   # skip TCXO entirely (crystal mode)
-sudo ./lora_rx -v --433 --tcxo-27     # TCXO 2.7V
-sudo ./lora_rx -v --433 --tcxo-33     # TCXO 3.3V (default)
-```
+If TX/RX runs but packets never arrive — check that DIO5/DIO6 reach the RF
+switch on your module. Without the switch, the antenna path is disconnected.
 
-The one that gets past "Calibrate done" is your module's config.
-Use the same TCXO flag on TX and RX.
-
-If using the 2.4 GHz antenna instead:
+To try 2.4 GHz instead (different antenna required):
 
 ```sh
 sudo ./lora_rx -v --24
 sudo ./lora_tx -v --24
 ```
 
+If the chip is stuck in bootloader (fw < 0x02xx), escape with:
+
+```sh
+sudo ./lora_rx --reset
+```
+
 ---
 
 ## IMU debug
@@ -107,14 +116,3 @@ stty -F /dev/serial0 38400 raw && cat /dev/serial0   # raw NMEA bytes
 ./gps_test -v -a                                      # all sentences
 ./gps_test -b 9600                                    # try different baud
 ```
-
----
-
-## TCXO voltage reference
-
-| Flag | Value | Voltage |
-|------|-------|---------|
-| `--tcxo-none` | 0xFF | no TCXO (crystal) |
-| `--tcxo-27`   | 0x05 | 2.7V |
-| `--tcxo-33`   | 0x07 | 3.3V |
-| `--tcxo-v N`  | 0x00–0x07 | raw byte |
diff --git a/shader_example/shader.cpp b/shader_example/shader.cpp
index fc4c952..0f038d9 100644
--- a/shader_example/shader.cpp
+++ b/shader_example/shader.cpp
@@ -30,7 +30,7 @@ GLuint compile(GLenum t, const std::string& src)
     if (!ok) {
         char log[1024];
         glGetShaderInfoLog(s, sizeof(log), NULL, log);
-        std::cout << "shader compile failed:\n" << log;
+        std::cerr << "shader compile failed:\n" << log;
     }
     return s;
 }
@@ -51,8 +51,8 @@ int main()
 
     if(!img1 || !img2)
     {
-        std::cout << "image load failed\n";
-        return 0;
+        std::cerr << "image load failed\n";
+        return 1;
     }
 
     // ---------------- TEXTURES ----------------
@@ -99,7 +99,8 @@ int main()
     if (!linked) {
         char log[1024];
         glGetProgramInfoLog(prog, sizeof(log), NULL, log);
-        std::cout << "program link failed:\n" << log;
+        std::cerr << "program link failed:\n" << log;
+        return 1;
     }
 
     // ---------------- QUAD (FIXED) ----------------
@@ -133,8 +134,10 @@ int main()
     glBindFramebuffer(GL_FRAMEBUFFER,fbo);
     glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,outTex,0);
 
-    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
-        std::cout << "FBO broken\n";
+    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+        std::cerr << "FBO broken\n";
+        return 1;
+    }
 
     // ---------------- RENDER ----------------
     glUseProgram(prog);