lora: Initial work at LoRaWAN support.

Author: kallisti5

platformio.ini

@@ -298,12 +298,20 @@ board_build.extra_flags = "-DARDUINO_ESP32_GATEWAY=\'E\'"
 platform = ${common.platform_esp32}
 board = heltec_wifi_lora_32_V2
 framework = arduino
-lib_deps = ${common.lib_deps}
+lib_deps =
+	${common.lib_deps}
+	MCCI LoRaWAN LMIC library
 src_build_flags =
   ${common.version}.dev
   ${common.src_build_flags}
   ${common.src_build_flags_esp32}
   ${common.debug_flags_esp32}
+  -DENABLE_LORA=1
+  -DLORA_NSS=18
+  -DLORA_RST=14
+  -DLORA_DIO0=26
+  -DLORA_DIO1=35
+  -DLORA_DIO2=34
   -DWIFI_LED=25
   -DWIFI_BUTTON=2
   -DWIFI_LED_ON_STATE=HIGH

src/input.cpp

@@ -99,6 +99,27 @@ void create_rapi_json(String &data)
   //DEBUG.print(emoncms_server.c_str() + String(url));
 }
 
+
+/// A small packed report of unit's status
+void create_rapi_packed(uint8_t *data)
+{
+  if (sizeof(data[0]) / sizeof(data) != 8) {
+    DBUGF("create_rapi_packed: Incorrect data size passed!");
+    return;
+  }
+  // Values with potential > 255 are reduced via a
+  // conversion factor.
+  data[0] = state;
+  data[1] = volt / 2;		// CF * 2
+  data[2] = amp;
+  data[3] = pilot;
+  data[4] = elapsed / 60;	// CF * 60
+  data[5] = temp1 / 10;		// CF * 10
+  data[6] = temp2 / 10;		// CF * 10
+  data[7] = temp3 / 10;		// CF * 10
+}
+
+
 // -------------------------------------------------------------------
 // OpenEVSE Request
 //

src/input.h

@@ -67,6 +67,7 @@ extern String ohm_hour;
 extern void handleRapiRead();
 extern void update_rapi_values();
 extern void create_rapi_json(String &data);
+extern void create_rapi_packed(uint8_t *data);
 
 extern void input_setup();
 

src/lora.cpp

@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2019-2020 Alexander von Gluck IV for OpenEVSE
+ *
+ * -------------------------------------------------------------------
+ *
+ * Additional Adaptation of OpenEVSE ESP Wifi
+ * by Trystan Lea, Glyn Hudson, OpenEnergyMonitor
+ * All adaptation GNU General Public License as below.
+ *
+ * -------------------------------------------------------------------
+ *
+ * This file is part of Open EVSE.
+ * Open EVSE 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, or (at your option)
+ * any later version.
+ * Open EVSE 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 Open EVSE; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+#ifdef ENABLE_LORA
+
+#include <lmic.h>
+#include <hal/hal.h>
+#include <SPI.h>
+
+#include "emonesp.h"
+#include "lora.h"
+
+#include "app_config.h"
+
+
+#define LORA_HTOI(c) ((c<='9')?(c-'0'):((c<='F')?(c-'A'+10):((c<='f')?(c-'a'+10):(0))))
+#define LORA_TWO_HTOI(h, l) ((LORA_HTOI(h) << 4) + LORA_HTOI(l))
+#define LORA_HEX_TO_BYTE(a, h, n) { for (int i = 0; i < n; i++) (a)[i] = LORA_TWO_HTOI(h[2*i], h[2*i + 1]); }
+#define LORA_DEVADDR(a) (uint32_t) ((uint32_t) (a)[3] | (uint32_t) (a)[2] << 8 | (uint32_t) (a)[1] << 16 | (uint32_t) (a)[0] << 24)
+
+#define ANNOUNCE_INTERVAL 30 * 1000 // (In Milliseconds)
+
+
+// TODO: Store these via WebUI? We're doing (simple) ABP activation for now
+const char *devAddr = "00000000";
+const char *nwkSKey = "00000000000000000000000000000000";
+const char *appSKey = "00000000000000000000000000000000";
+
+
+// LoRaWAN credentials to use
+static uint8_t DEVADDR[4];
+static uint8_t NWKSKEY[16];
+static uint8_t APPSKEY[16];
+
+// Next LoRaWAN announcement
+unsigned long nextAnnounce;
+
+// LoRa module pin mapping
+const lmic_pinmap lmic_pins = {
+  .nss = LORA_NSS,
+  .rxtx = LMIC_UNUSED_PIN,
+  .rst = LORA_RST,
+  .dio = {LORA_DIO0, LORA_DIO1, LORA_DIO2},
+};
+
+// Used for OTAA, not used (yet)
+void os_getArtEui (u1_t* buf) { }
+void os_getDevEui (u1_t* buf) { }
+void os_getDevKey (u1_t* buf) { }
+
+
+void onEvent(ev_t ev) {
+  switch (ev) {
+    case EV_TXCOMPLETE:
+      DBUGF("LoRa: TX Complete.");
+      // LoRaWAN transmission complete
+      if (LMIC.txrxFlags & TXRX_ACK) {
+        // Received ack
+        DBUGF("LoRa: TX ack.");
+      }
+      break;
+    case EV_TXSTART:
+      DBUGF("LoRa: TX Begin.");
+      break;
+    default:
+      // Ignore anything else for now
+      break;
+  }
+}
+
+/// Reset LoRa modem. Reload LoRaWAN keys
+void lora_reset()
+{
+  LORA_HEX_TO_BYTE(DEVADDR, devAddr, 4);
+  LORA_HEX_TO_BYTE(NWKSKEY, nwkSKey, 16);
+  LORA_HEX_TO_BYTE(APPSKEY, appSKey, 16);
+
+  LMIC_reset();
+  LMIC_setSession (0x13, LORA_DEVADDR(DEVADDR), NWKSKEY, APPSKEY);
+  LMIC_setAdrMode(0);
+  LMIC_setClockError(MAX_CLOCK_ERROR * 10 / 100);
+  LMIC_selectSubBand(1);
+  LMIC_setLinkCheckMode(0);
+  LMIC.dn2Dr = DR_SF7;
+}
+
+
+/// Initial setup of LoRa modem.
+void lora_setup()
+{
+  Profile_Start(lora_setup);
+
+  os_init();
+  lora_reset();
+
+  // Set us up for an immeadiate announcement
+  nextAnnounce = millis();
+ 
+  Profile_End(lora_setup, 1);
+}
+
+
+void lora_publish(uint8_t *dataPacket)
+{
+  if (millis() < nextAnnounce)
+    return;
+
+  Profile_Start(lora_loop);
+  DBUGF("LoRa: Starting LoRaWAN broadcast...");
+  // Check if there is not a current TX/RX job running
+  if (LMIC.opmode & OP_TXRXPEND) {
+    DBUGF("LoRa: Modem busy. Retry later");
+    return;
+  } 
+
+  LMIC_setTxData2(1, dataPacket, sizeof(dataPacket), true);
+  nextAnnounce = millis() + ANNOUNCE_INTERVAL;
+
+  Profile_End(lora_loop, 1);
+}
+
+#else /* !ENABLE_LORA */
+
+#include "emonesp.h"
+#include "app_config.h"
+
+void lora_setup() { /*NOP*/ }
+void lora_reset() { /*NOP*/ }
+void lora_publish(uint8_t *dataPacket) { /*NOP*/ }
+
+#endif

src/lora.h

@@ -0,0 +1,10 @@
+#ifndef _LORA_H
+#define _LORA_H
+
+
+void lora_setup();
+void lora_reset();
+void lora_publish(uint8_t *dataPacket);
+
+
+#endif // _LORA_H

src/main.cpp

@@ -40,6 +40,7 @@
 #include "divert.h"
 #include "ota.h"
 #include "lcd.h"
+#include "lora.h"
 #include "openevse.h"
 #include "root_ca.h"
 #include "hal.h"
@@ -78,6 +79,12 @@ void setup()
   net_setup();
   DBUGF("After net_setup: %d", HAL.getFreeHeap());
 
+#ifdef ENABLE_LORA
+  // Initialise LoRa if supported
+  lora_setup();
+  DBUGF("After lora_setup: %d", HAL.getFreeHeap());
+#endif
+
   // Initialise Mongoose networking library
   Mongoose.begin();
   Mongoose.setRootCa(root_ca);
@@ -200,6 +207,12 @@ loop() {
     }
   } // end WiFi connected
 
+#ifdef ENABLE_LORA
+  uint8_t loraPacket[8];
+  create_rapi_packed(loraPacket);
+  lora_publish(loraPacket);
+#endif
+
   Profile_End(loop, 10);
 } // end loop