lora: Initial support for sensor example

Signed-off-by: Alistair Francis <alistair@alistair23.me>

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "lvgl/lvgl"]
 	path = lvgl/lvgl
 	url = https://github.com/littlevgl/lvgl.git
+[submodule "examples/lora/RadioLib"]
+	path = examples/lora/RadioLib
+	url = https://github.com/jgromes/RadioLib.git

examples/lora/README.md

@@ -0,0 +1,25 @@
+LoRa
+====
+
+LoRa (Long Range) is a radio communication technique that uses
+spread spectrum modulation technique derived from chirp spread
+spectrum (CSS) technology.
+
+LoRa provides a number of properties including:
+
+ * long range, can cover tens of kilometres
+ * low power, devices can run for years
+ * reasonably secure
+ * standardised
+ * relativity cheap
+
+This directory contains a range of examples using
+[RadioLib](https://github.com/jgromes/RadioLib) to
+support LoRa on Tock.
+
+Before the examples will work you first need to build
+RadioLib.
+
+```shell
+$ build-RadioLib.sh
+```

examples/lora/build-RadioLib.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+pushd RadioLib/examples/NonArduino/Tock/
+
+rm -rf build
+
+# Change the source to point to the current libtock-c directory
+sed -i 's|${CMAKE_CURRENT_SOURCE_DIR}/libtock-c|../../../../../../../|g' CMakeLists.txt
+sed -i 's|target_include_directories(${PROJECT_NAME} PUBLIC|target_include_directories(\${PROJECT_NAME}\n    PUBLIC ../../../../../../|g' CMakeLists.txt
+
+mkdir -p build
+cd build
+
+cmake -G "CodeBlocks - Unix Makefiles" ..
+
+# Build the Tock example application
+# This will fail to link, as it can't find the libtock-c libraries
+# That's fine for us though, as we just need to build the RadioLib
+# library, not the entire example application
+make -j4 2> /dev/null
+
+popd

examples/lora/sensor-transmit/Makefile

@@ -0,0 +1,26 @@
+# Makefile for user application
+
+# Specify this directory relative to the current application.
+TOCK_USERLAND_BASE_DIR = ../../../
+
+# Which files to compile.
+CXX_SRCS := $(wildcard *.cc)
+
+# Include the core RadioLib headers
+override CPPFLAGS += -I../RadioLib/src
+
+# Include the Tock specific headers
+override CPPFLAGS += -I../RadioLib/examples/NonArduino/Tock
+
+# Include the base of libtock-c to fix the libtock/ includes from RadioLib
+override CPPFLAGS += -I$(TOCK_USERLAND_BASE_DIR)/
+
+override LEGACY_LIBS_cortex-m += ../RadioLib/examples/NonArduino/Tock/build/RadioLib/libRadioLib.a
+override LEGACY_LIBS_cortex-m0 += ../RadioLib/examples/NonArduino/Tock/build/RadioLib/libRadioLib.a
+override LEGACY_LIBS_cortex-m3 += ../RadioLib/examples/NonArduino/Tock/build/RadioLib/libRadioLib.a
+override LEGACY_LIBS_cortex-m4 += ../RadioLib/examples/NonArduino/Tock/build/RadioLib/libRadioLib.a
+override LEGACY_LIBS_cortex-m7 += ../RadioLib/examples/NonArduino/Tock/build/RadioLib/libRadioLib.a
+
+# Include userland master makefile. Contains rules and flags for actually
+# building the application.
+include $(TOCK_USERLAND_BASE_DIR)/AppMakefile.mk

examples/lora/sensor-transmit/README.md

@@ -0,0 +1,16 @@
+Sensor Transmitter
+==================
+
+This example builds an application that can either transmit sensor data
+or receive sensor data, depending on the state of the `SEND` macro in
+`main.cc`.
+
+Before the examples will work you first need to build
+RadioLib.
+
+```shell
+cd ../
+$ build-RadioLib.sh
+cd sensor-transmit
+make
+```

examples/lora/sensor-transmit/main.cc

@@ -0,0 +1,106 @@
+/*
+  RadioLib Non-Arduino Tock Library test application
+
+  Licensed under the MIT or Apache License
+
+  Copyright (c) 2023 Alistair Francis <alistair@alistair23.me>
+*/
+
+// include the library
+#include <RadioLib.h>
+
+// include the hardware abstraction layer
+#include "libtockHal.h"
+
+// Include some libtock-c helpers
+#include <temperature.h>
+#include <humidity.h>
+
+#define BUFFER_LEN 64
+
+// Define if we should send or receieve data
+#define SEND
+
+// the entry point for the program
+int main(void) {
+  char buffer[BUFFER_LEN];
+
+  printf("[SX1261] Initialising Radio ... \n");
+
+  // create a new instance of the HAL class
+  TockHal* hal = new TockHal();
+
+  // now we can create the radio module
+  // pinout corresponds to the SparkFun LoRa Thing Plus - expLoRaBLE
+  // NSS pin:   0
+  // DIO1 pin:  2
+  // NRST pin:  4
+  // BUSY pin:  1
+  Module* tock_module = new Module(hal, RADIO_NSS, RADIO_DIO_1, RADIO_RESET, RADIO_BUSY);
+  SX1262* radio = new SX1262(tock_module);
+
+  // Setup the radio
+  // The settings here work for the SparkFun LoRa Thing Plus - expLoRaBLE
+  radio->XTAL = true;
+  int state = radio->begin(915.0);
+
+  if (state != RADIOLIB_ERR_NONE) {
+    printf("failed, code %d\r\n", state);
+    return 1;
+  }
+  printf("success!\r\n");
+
+#ifdef SEND
+  int temp = 0;
+  unsigned humi = 0;
+
+  // loop forever
+  for(;;) {
+    // Ensure there are no pending callbacks
+    yield_no_wait();
+
+    // Read some sensor data from the board
+    temperature_read_sync(&temp);
+    humidity_read_sync(&humi);
+
+    snprintf(buffer, BUFFER_LEN, "Temp: %d, Hum: %u", temp, humi);
+
+    // send a packet
+    printf("[SX1261] Transmitting '%s' \r\n", buffer);
+
+    state = radio->transmit(buffer);
+
+    if(state == RADIOLIB_ERR_NONE) {
+      // the packet was successfully transmitted
+      printf("success!\r\n");
+
+      // wait for a second before transmitting again
+      hal->delay(1000);
+    } else {
+      printf("failed, code %d\r\n", state);
+    }
+  }
+#else /* SEND */
+  printf("[SX1261] Receiving...\r\n");
+
+  // loop forever
+  for(;;) {
+    // Ensure there are no pending callbacks
+    yield_no_wait();
+
+    state = radio->receive((uint8_t*)buffer, BUFFER_LEN);
+
+    if(state == RADIOLIB_ERR_NONE) {
+      // the packet was successfully transmitted
+      printf("success!: %s\r\n", buffer);
+
+      // wait for a second before transmitting again
+      hal->delay(1000);
+    } else {
+      printf("failed, code %d\r\n", state);
+    }
+  }
+#endif
+
+  return 0;
+}