add protobuf generation

Dockerfile

@@ -11,7 +11,9 @@ gperf \
 python \
 python-serial \
 cmake \
-ninja-build
+ninja-build \
+protobuf-compiler \
+python-protobuf
 
 RUN mkdir /esp
 WORKDIR /esp

components/nanopb/CMakeLists.txt

@@ -0,0 +1,6 @@
+set(COMPONENT_SRCS "nanopb/pb_common.c"
+    "nanopb/pb_decode.c"
+    "nanopb/pb_encode.c")
+set(COMPONENT_ADD_INCLUDEDIRS "nanopb")
+
+register_component()

components/nanopb/functions.cmake

@@ -0,0 +1,20 @@
+function(nanopb_generate PROTO_FILE PB_OUT HDR_VAR SRC_VAR)
+    get_filename_component(PROTO_FILE_NAME ${PROTO_FILE} NAME_WE)
+    get_filename_component(PROTO_FILE_PATH ${PROTO_FILE} ABSOLUTE BASE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+    get_filename_component(PROTO_FILE_DIR ${PROTO_FILE_PATH} DIRECTORY)
+    set(PROTO_HDR "${PB_OUT}/${PROTO_FILE_NAME}.pb.h")
+    set(PROTO_SRC "${PB_OUT}/${PROTO_FILE_NAME}.pb.c")
+    list(APPEND "${HDR_VAR}" ${PROTO_HDR})
+    list(APPEND "${SRC_VAR}" ${PROTO_SRC})
+    if(NOT CMAKE_SCRIPT_MODE_FILE)
+        add_custom_command(OUTPUT ${PROTO_HDR} ${PROTO_SRC} 
+            COMMAND protoc 
+                --plugin=protoc-gen-nanopb=${CMAKE_CURRENT_LIST_DIR}/nanopb/generator/protoc-gen-nanopb 
+                --nanopb_out=${PB_OUT}
+                --proto_path ${PROTO_FILE_DIR}
+                ${PROTO_FILE_PATH}
+            DEPENDS ${PROTO_FILE_PATH})
+    endif()
+    list(APPEND ADDITIONAL_MAKE_CLEAN_FILES ${PROTO_HDR} ${PROTO_SRC})
+endfunction()
+

main/.gitignore

@@ -0,0 +1 @@
+/pb_out

main/CMakeLists.txt

@@ -1,8 +1,17 @@
-set(COMPONENT_SRCS "ugv_main.c"
+include(${CMAKE_CURRENT_LIST_DIR}/../components/nanopb/functions.cmake)
+
+set(PB_OUT ${CMAKE_CURRENT_SOURCE_DIR}/pb_out)
+
+nanopb_generate(messages.proto ${PB_OUT} PROTO_HDRS PROTO_SRCS)
+
+list(APPEND COMPONENT_SRCS "ugv_main.c"
     "ugv_comms.c"
-    "u8g2_esp32_hal.c")
+    "u8g2_esp32_hal.c"
-set(COMPONENT_ADD_INCLUDEDIRS ".")
+    ${PROTO_SRCS})
-set(COMPONENT_REQUIRES "u8g2" "sx127x_driver")
+set(COMPONENT_PRIV_INCLUDEDIRS "." ${PB_OUT})
+set(COMPONENT_REQUIRES "u8g2" "sx127x_driver" "nanopb")
+
+make_directory(${PB_OUT})
 
 register_component()
 

main/messages.proto

@@ -0,0 +1,43 @@
+syntax = "proto3";
+
+enum UGV_State {
+  IDLE = 0;
+  AQUIRING = 1;
+  DRIVING = 2;
+  FINISHED = 3;
+}
+
+message Location {
+  uint32 fix_quality = 1;
+  float latitude = 2;
+  float longitude = 3;
+  float altitude = 4;
+}
+
+message UGV_Status {
+  UGV_State state = 1;
+  Location location = 2;
+}
+
+message UGV_Message {
+  oneof ugv_message {
+    UGV_Status status = 1;
+    uint32 command_ack = 2;
+  }
+}
+
+enum GroundCommandType {
+  DISABLE = 0;
+  ENABLE = 1;
+}
+
+message GroundCommand {
+  uint32 id = 1;
+  GroundCommandType type = 2;
+}
+
+message GroundMessage {
+  oneof ground_message {
+    GroundCommand command = 1;
+  }
+}

main/ugv_main.c

@@ -9,6 +9,9 @@
 #include "u8g2_esp32_hal.h"
 #include "ugv_comms.h"
 #include "ugv_config.h"
+#include "messages.pb.h"
+
+#include <pb_decode.h>
 
 static const char *TAG = "ugv_main";