Extra program for testing added, separate from demo/example

CMakeLists.txt

@@ -23,6 +23,12 @@ FetchContent_MakeAvailable(ax25_aprs_lib)
 add_library(ax25_aprs_lib::ax25beacon ALIAS ax25beacon)
 
 
+# Compiler options
+
+# Enable on demand only, since warnings from 3rd-party code will flood the console
+# set(APRS_PICO_COMPILE_WARN_OPTIONS -Wundef -Wswitch-enum -Wall -Wextra -pedantic)
+
+
 # ##### Configure the build of the 'aprs_pico' library #####
 
 set(TARGET_LIB_NAME aprs_pico)
@@ -30,17 +36,18 @@ set(TARGET_LIB_NAME aprs_pico)
 add_library(${TARGET_LIB_NAME}
     src/aprs_pico.c)
 
-set_target_properties(${TARGET_LIB_NAME}
+target_compile_options(${TARGET_LIB_NAME}
-    PROPERTIES
+  PRIVATE "${APRS_PICO_COMPILE_WARN_OPTIONS}"
-    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
 )
 
 target_include_directories(${TARGET_LIB_NAME} PUBLIC
     include
 )
 
-# Enable on demand
+set_target_properties(${TARGET_LIB_NAME}
-#target_compile_options(${TARGET_LIB_NAME} PRIVATE "-Wundef;-Wall")
+    PROPERTIES
+    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
   
 target_link_libraries(${TARGET_LIB_NAME}
     ax25_aprs_lib::ax25beacon
@@ -49,29 +56,54 @@ target_link_libraries(${TARGET_LIB_NAME}
 )
 
 
-# ##### Configure the build of the example application #####
+# ##### Configure the build of the DEMO applications #####
 
-set(TARGET_EXAMPLE_EXE_NAME aprs_pico_example)
+set(TARGET_DEMO_EXE_NAME aprs_pico_beacon_demo)
 
-add_executable(${TARGET_EXAMPLE_EXE_NAME}
+add_executable(${TARGET_DEMO_EXE_NAME}
-    src/aprs_pico_example.c
+    src/aprs_pico_beacon_demo.c
 )
 
-target_include_directories(${TARGET_EXAMPLE_EXE_NAME} PRIVATE
+target_compile_options(${TARGET_DEMO_EXE_NAME}
+  PRIVATE "${APRS_PICO_COMPILE_WARN_OPTIONS}"
+)
+
+target_include_directories(${TARGET_DEMO_EXE_NAME} PRIVATE
   include
 )
 
-# Configure the console interface
-pico_enable_stdio_usb(${TARGET_EXAMPLE_EXE_NAME} 1) # USB
-#pico_enable_stdio_uart(${TARGET_EXAMPLE_EXE_NAME} 1) # UART
-
 # Create map/bin/hex file etc.
-pico_add_extra_outputs(${TARGET_EXAMPLE_EXE_NAME})
+pico_add_extra_outputs(${TARGET_DEMO_EXE_NAME})
 
-target_link_libraries(${TARGET_EXAMPLE_EXE_NAME}
+target_link_libraries(${TARGET_DEMO_EXE_NAME}
     ${TARGET_LIB_NAME}
     ax25_aprs_lib::ax25beacon
     pico_audio_pwm        
     pico_stdlib
 )
 
+
+# ##### Configure the build of the TEST application #####
+
+set(TARGET_TEST_EXE_NAME aprs_pico_tone_test)
+
+add_executable(${TARGET_TEST_EXE_NAME}
+    src/aprs_pico_tone_test.c
+)
+
+target_compile_options(${TARGET_TEST_EXE_NAME}
+  PRIVATE "${APRS_PICO_COMPILE_WARN_OPTIONS}"
+)
+
+target_include_directories(${TARGET_TEST_EXE_NAME} PRIVATE
+  include
+)
+
+# Create map/bin/hex file etc.
+pico_add_extra_outputs(${TARGET_TEST_EXE_NAME})
+
+target_link_libraries(${TARGET_TEST_EXE_NAME}
+    ${TARGET_LIB_NAME}
+    pico_audio_pwm        
+    pico_stdlib
+)

README.md

@@ -13,7 +13,7 @@ An analog line-out audio signal will be generated by a band-pass filter connecte
 
 Image: Line-out signal (see [below](#Hardware)) probed by a DSO. We clearly see the 1200 Hz and 2200 Hz tones of the 1200 Bd 2-AFSK.
 
-Both a static library `libaprs_pico.a` and an example application will be generated by the build.
+Both a static library `libaprs_pico.a` and a demo application will be generated by the build.
 
 
 ## Prerequisites
@@ -39,7 +39,7 @@ We just need a simple band-pass filter to extract the analog AFSK-signal from th
 
 The line-out voltage can be as high as 2.7 V<sub>pp</sub> (~1 V<sub>rms</sub>) (at full-scale volume setting in the software and high-impedance load).
 
-## Build the library and the example application
+## Build the library and the 'beacon' demo application
 
 ```
 git clone https://github.com/eleccoder/raspi-pico-aprs-tnc.git
@@ -48,18 +48,18 @@ cmake -S . -B build
 cmake --build build
 ```
 
-`build/lib/libaprs_pico.a` and `build/aprs_pico_example[.uf2|.elf|.bin]` will be generated.
+`build/lib/libaprs_pico.a` and `build/aprs_pico_beacon_demo[.uf2|.elf|.bin|.hex]` will be generated, as well as the testing application `build/aprs_pico_tone_test[.uf2|.elf|.bin|.hex]`.
 
-## Run the example application
+## Run the 'beacon' demo application
 
 ```
 cd build
-Flash 'aprs_pico_example[.uf2|.elf|.bin]' to the Pico board as usual
+Flash 'aprs_pico_beacon_demo[.uf2|.elf|.bin|.hex]' to the Pico board as usual.
 ```
 
 The analog AFSK audio signal will be available at the filter's line-out. You can probe it by a scope, listen to it by using an audio amp, or connect it to any RF transceiver to send it on the air (ham radio license required).
 
-## Test the example application using *Dire Wolf* (on LINUX)
+## Test the 'beacon' demo application using *Dire Wolf* (on LINUX)
 
 We can use the famous [Dire Wolf](https://github.com/wb2osz/direwolf) CLI software to decode the APRS data after sampling our APRS audio signal by means of a soundcard.
 
@@ -94,5 +94,6 @@ arecord -f cd -c 1 -t raw - | direwolf
 
 ## Ingredients / Acknowledgements
 
-- For APRS => AX.25 => PCM conversion I'm using [my modified version](https://github.com/eleccoder/ax25-aprs-lib) of [fsphil's ax25beacon](https://github.com/fsphil/ax25beacon)
+- For `APRS => AX.25 => PCM` conversion I'm using [my modified version](https://github.com/eleccoder/ax25-aprs-lib) of [fsphil's ax25beacon](https://github.com/fsphil/ax25beacon) project.
-- For PCM => PWM conversion I'm using the `pico_audio_pwm` library from [pico-extras](https://github.com/raspberrypi/pico-extras) (NOTE: ATTOW, maturity seems to be rather alpha/beta)
+- For `PCM => PWM` conversion I'm using the `pico_audio_pwm` library from [pico-extras](https://github.com/raspberrypi/pico-extras) (NOTE: ATTOW, maturity seems to be rather alpha/beta).
+- Basic PWM audio rendering with the Pi Pico has been spotted in the [pico-playground](https://github.com/raspberrypi/pico-playground/tree/master/audio).

include/aprs_pico.h

@@ -16,13 +16,12 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef APRS_PICO_H
+#pragma once
-#define APRS_PICO_H
 
 #include <stdint.h>
 #include <stdbool.h>
 
-#include <pico/audio_pwm.h> // For 'audio_buffer_pool_t'
+#include "pico/audio_pwm.h" // For 'audio_buffer_pool_t'
 
 
 /** \brief Initializes the APRS Pico library
@@ -69,5 +68,3 @@ bool aprs_pico_sendAPRS(audio_buffer_pool_t* audio_buffer_pool,
  * \param[in]      volume             The volume level of the generated signal (0 ... 256)
  */
 void aprs_pico_send_sine_wave(audio_buffer_pool_t* audio_buffer_pool, unsigned int freq_in_hz, unsigned int sample_freq_in_hz, uint16_t volume);
-
-#endif // APRS_PICO_H

src/aprs_pico.c

@@ -16,19 +16,18 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <aprs_pico.h>
+#include "aprs_pico.h"
+
+#include "ax25beacon.h"
+#include "pico/stdlib.h"
 
-#include <stdio.h>
 #include <math.h>
 
-#include <pico/stdlib.h>
-#include <ax25beacon.h>
 
-
+// NOTE: ATTOW, the pico-extra audio PWM lib worked only at a fixed 22050 Hz sampling frequency, while the
-// WARNING: ATTOW, the pico audio PWM lib worked only @ 22050 Hz sampling frequency and 48 MHz system clock
+//       system clock runs at 48 MHz. This is documented here: https://github.com/raspberrypi/pico-extras
-//          This is documented here: https://github.com/raspberrypi/pico-extras
+#define APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__FIXED_SAMPLE_FREQ_IN_HZ  (22050)
-#define APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB_FIXED_SAMPLE_FREQ_IN_HZ  (22050)
+#define APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__SYS_CLOCK_FREQ_OF_IN_MHZ (48)
-#define APRS_PICO__SYS_CLOCK_FREQ_OF_PICO_EXTRA_AUDIO_PWM_LIB_IN_MHZ (48)
 
 
 typedef struct AudioCallBackUserData
@@ -81,14 +80,14 @@ static audio_buffer_pool_t* aprs_pico_initAudio(unsigned int sample_freq_in_hz,
  */
 static void aprs_pico_initClock(unsigned int sample_freq_in_hz)
 {
-  // WARNING: ATTOW, the pico audio PWM lib worked only @ 22050 Hz sampling frequency and 48 MHz system clock
+  // NOTE: ATTOW, the pico-extra audio PWM lib worked only at a fixed 22050 Hz sampling frequency, while the
-  //          This is documented here: https://github.com/raspberrypi/pico-extras
+  //       system clock runs at 48 MHz. This is documented here: https://github.com/raspberrypi/pico-extras
 
-  // Compensate a non-'PICO_EXTRA_AUDIO_PWM_LIB_FIXED_SAMPLE_FREQ_IN_HZ' sampling frequency
+  // Compensate a non-'APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__FIXED_SAMPLE_FREQ_IN_HZ' sampling frequency
-  // by adapting the system clock accordingly
+  // by adapting the system clock frequency accordingly.
 
-  float sys_clock_in_mhz = (float)APRS_PICO__SYS_CLOCK_FREQ_OF_PICO_EXTRA_AUDIO_PWM_LIB_IN_MHZ *
+  float sys_clock_in_mhz = (float)APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__SYS_CLOCK_FREQ_OF_IN_MHZ *
-                           ((float)sample_freq_in_hz / (float)APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB_FIXED_SAMPLE_FREQ_IN_HZ);
+                           ((float)sample_freq_in_hz / (float)APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__FIXED_SAMPLE_FREQ_IN_HZ);
 
   if (!set_sys_clock_khz((uint32_t)(1000.0f * sys_clock_in_mhz), false))
     {
@@ -177,7 +176,7 @@ static void aprs_pico_sendAPRSAudioCallback(const void* callback_user_data, cons
 // See the header file for documentation
 audio_buffer_pool_t* aprs_pico_init()
 {
-  audio_buffer_pool_t* audio_buffer_pool = aprs_pico_initAudio(APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB_FIXED_SAMPLE_FREQ_IN_HZ,
+  audio_buffer_pool_t* audio_buffer_pool = aprs_pico_initAudio(APRS_PICO__PICO_EXTRA_AUDIO_PWM_LIB__FIXED_SAMPLE_FREQ_IN_HZ,
                                                                AUDIO_BUFFER_FORMAT_PCM_S16);
   return audio_buffer_pool;
 }

src/aprs_pico_beacon_demo.c

@@ -16,11 +16,8 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <aprs_pico.h>
+#include "aprs_pico.h"
-#include <pico/stdlib.h>
+#include "pico/stdlib.h"
-
-#define SINE_WAVE_TEST (0) // For testing & debugging
-
 
 
 int main()
@@ -29,17 +26,8 @@ int main()
 
   audio_buffer_pool_t* audio_buffer_pool = aprs_pico_init();
 
-#if (SINE_WAVE_TEST == 1)
+  // Let the altitude run over time
-
+  double alt_in_m = 0.0;
-  const unsigned int FREQ_IN_HZ        = 1000u;
-  const unsigned int SAMPLE_FREQ_IN_HZ = 48000u;
-  const uint16_t     VOLUME            = 128u;
-
-  aprs_pico_send_sine_wave(audio_buffer_pool, FREQ_IN_HZ, SAMPLE_FREQ_IN_HZ, VOLUME);
-
-#else // !SINE_WAVE_TEST
-
-  double alt_in_m = 0.0f;
 
   while (true) // Loop forever
     {
@@ -49,16 +37,15 @@ int main()
                          "DL3TG",  // Destination call sign
                          "PATH1",  // APRS path #1
                          "PATH2",  // APRS path #2
-                         "APRS by RPi-Pico - https://github.com/eleccoder/raspi-pico-aprs-tnc", // APRS message
+                         "APRS by RPi-Pico - https://github.com/eleccoder/raspi-pico-aprs-tnc", // Text message
                          10.0,     // Latitude  (in deg)
                          20.0,     // Longitude (in deg)
                          alt_in_m, // Altitude  (in m)
                          128u);    // Volume    (0 ... 256)
 
+      // Don't raise too high ...
       alt_in_m = (alt_in_m < 1000.0) ? alt_in_m + 100.0 : 0.0;
     }
 
-#endif // SINE_WAVE_TEST, !SINE_WAVE_TEST
-
   return 0;
 }

src/aprs_pico_tone_test.c

@@ -0,0 +1,38 @@
+/*
+* Project 'raspi-pico-aprs-tnc'
+* Copyright (C) 2021-2023 Thomas Glau, DL3TG
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+
+* You should have received a copy of the GNU General Public License
+* along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "aprs_pico.h"
+#include "pico/stdlib.h"
+
+
+int main()
+{
+  // 48 kHz is used as a default by the underlying https://github.com/eleccoder/ax25-aprs-lib library
+  // The PWM base frequency is expected to be 16 * SAMPLE_FREQ_IN_HZ
+  const unsigned int SAMPLE_FREQ_IN_HZ = 48000u;
+
+  const unsigned int TONE_FREQ_IN_HZ   = 1000u;
+  const uint16_t     VOLUME            = 128u;   // 0 ... 256
+
+  stdio_init_all();
+  audio_buffer_pool_t* audio_buffer_pool = aprs_pico_init();
+
+  aprs_pico_send_sine_wave(audio_buffer_pool, TONE_FREQ_IN_HZ, SAMPLE_FREQ_IN_HZ, VOLUME);
+
+  return 0;
+}