Initial check-in

src/TheThingsNetwork.cpp

@@ -0,0 +1,238 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Manuel Bleichenbacher
+ * 
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * This the hardware abstraction layer to run LMIC in on ESP32 using ESP-iDF.
+ *******************************************************************************/
+
+#include "TheThingsNetwork.h"
+#include "esp_log.h"
+#include "oslmic.h"
+#include "hal.h"
+#include "hal_esp32.h"
+#include "lmic.h"
+
+static const char *TAG = "ttn";
+
+static TheThingsNetwork* ttnInstance;
+static uint8_t appEui[8];
+static uint8_t appKey[16];
+static uint8_t devEui[8];
+
+static bool hexStringToBin(const char *hex, uint8_t *buf, int len);
+static int hexTupleToByte(const char *hex);
+static int hexDigitToVal(char ch);
+static void swapByteOrder(uint8_t* buf, int len);
+
+
+TheThingsNetwork::TheThingsNetwork(uint8_t sf, uint8_t fsb)
+{
+    ttnInstance = this;
+    spreadingFactor = sf;
+    frequencySubband = fsb;
+    hal_initCriticalSection();
+}
+
+TheThingsNetwork::~TheThingsNetwork()
+{
+    // nothing to do
+}
+
+void TheThingsNetwork::configurePins(spi_host_device_t spi_host, uint8_t nss, uint8_t rxtx, uint8_t rst, uint8_t dio0, uint8_t dio1)
+{
+    lmic_pins.spi_host = spi_host;
+    lmic_pins.nss = nss;
+    lmic_pins.rxtx = rxtx;
+    lmic_pins.rst = rst;
+    lmic_pins.dio0 = dio0;
+    lmic_pins.dio1 = dio1;
+
+    os_init();
+    reset();
+
+    hal_startBgTask();
+}
+
+void TheThingsNetwork::reset()
+{
+    hal_enterCriticalSection();
+    LMIC_reset();
+    hal_leaveCriticalSection();
+}
+
+bool TheThingsNetwork::provision(const char *appEui, const char *appKey, const char* devEui)
+{
+    return decodeKeys(appEui, appKey, devEui);
+}
+
+bool TheThingsNetwork::decodeKeys(const char *appEui, const char *appKey, const char* devEui)
+{
+    if (strlen(appEui) != 16 || !hexStringToBin(appEui, ::appEui, 8))
+    {
+        ESP_LOGW(TAG, "Invalid application EUI: %s", appEui);
+        return false;
+    }
+
+    swapByteOrder(::appEui, 8);
+
+    if (strlen(appKey) != 32 || !hexStringToBin(appKey, ::appKey, 16))
+    {
+        ESP_LOGW(TAG, "Invalid application key: %s", appEui);
+        return false;
+    }
+
+    if (strlen(devEui) != 16 || !hexStringToBin(devEui, ::devEui, 8))
+    {
+        ESP_LOGW(TAG, "Invalid device EUI: %s", devEui);
+        return false;
+    }
+
+    swapByteOrder(::devEui, 8);
+
+    return true;
+}
+
+bool TheThingsNetwork::join(const char *appEui, const char *appKey, const char *devEui, int8_t retries, uint32_t retryDelay)
+{
+    if (!decodeKeys(appEui, appKey, devEui))
+        return false;
+    
+    return join(retries, retryDelay);
+}
+
+bool TheThingsNetwork::join(int8_t retries, uint32_t retryDelay)
+{
+    hal_enterCriticalSection();
+    LMIC_startJoining();
+    hal_wakeUp();
+    hal_leaveCriticalSection();
+    return true;
+}
+
+ttn_response_t TheThingsNetwork::sendBytes(const uint8_t *payload, size_t length, port_t port, bool confirm, uint8_t sf)
+{
+    hal_enterCriticalSection();
+    if (LMIC.opmode & OP_TXRXPEND)
+    {
+        hal_leaveCriticalSection();
+        return TTN_ERROR_SEND_COMMAND_FAILED;
+    }
+
+    LMIC_setTxData2(port, (xref2u1_t)payload, length, confirm);
+    hal_wakeUp();
+    hal_leaveCriticalSection();
+    return TTN_SUCCESSFUL_TRANSMISSION;
+}
+
+
+// --- LMIC functions ---
+
+#if CONFIG_LOG_DEFAULT_LEVEL >= 3
+static const char *eventNames[] = {
+    NULL,
+    "EV_SCAN_TIMEOUT", "EV_BEACON_FOUND",
+    "EV_BEACON_MISSED", "EV_BEACON_TRACKED", "EV_JOINING",
+    "EV_JOINED", "EV_RFU1", "EV_JOIN_FAILED", "EV_REJOIN_FAILED",
+    "EV_TXCOMPLETE", "EV_LOST_TSYNC", "EV_RESET",
+    "EV_RXCOMPLETE", "EV_LINK_DEAD", "EV_LINK_ALIVE"
+};
+#endif
+
+// This EUI must be in little-endian format, so least-significant-byte first.
+// When copying an EUI from ttnctl output, this means to reverse the bytes.
+// For TTN issued EUIs the last bytes should be 0xD5, 0xB3, 0x70.
+// The order is swapped in TheThingsNetwork::provision().
+void os_getArtEui (u1_t* buf)
+{
+    memcpy(buf, appEui, 8);
+}
+
+// This should also be in little endian format, see above.
+void os_getDevEui (u1_t* buf)
+{
+    memcpy(buf, devEui, 8);
+}
+
+// This key should be in big endian format (or, since it is not really a number
+// but a block of memory, endianness does not really apply). In practice, a key
+// taken from ttnctl can be copied as-is.
+void os_getDevKey (u1_t* buf)
+{
+    memcpy(buf, appKey, 16);
+}
+
+void onEvent (ev_t ev) {
+    #if CONFIG_LOG_DEFAULT_LEVEL >= 3
+        ESP_LOGI(TAG, "%ld: event %s", os_getTime(), eventNames[ev]);
+    #endif
+
+    if (ev == EV_JOINED)
+    {
+        // Disable link check validation (automatically enabled
+        // during join, but not supported by TTN at this time).
+        LMIC_setLinkCheckMode(0);
+    } else if (ev == EV_TXCOMPLETE) {
+            if (LMIC.txrxFlags & TXRX_ACK)
+              printf("Received ack\n");
+            if (LMIC.dataLen) {
+              printf("Received %d bytes of payload\n", LMIC.dataLen);
+            }
+    }
+}
+
+
+// --- Helper functions ---
+
+bool hexStringToBin(const char *hex, uint8_t *buf, int len)
+{
+    const char* ptr = hex;
+    for (int i = 0; i < len; i++)
+    {
+        int val = hexTupleToByte(ptr);
+        if (val < 0)
+            return false;
+        buf[i] = val;
+        ptr += 2;
+    }
+    return true;
+}
+
+int hexTupleToByte(const char *hex)
+{
+    int nibble1 = hexDigitToVal(hex[0]);
+    if (nibble1 < 0)
+        return -1;
+    int nibble2 = hexDigitToVal(hex[1]);
+    if (nibble2 < 0)
+        return -1;
+    return (nibble1 << 4) | nibble2;
+}
+
+int hexDigitToVal(char ch)
+{
+    if (ch >= '0' && ch <= '9')
+        return ch - '0';
+    if (ch >= 'A' && ch <= 'F')
+        return ch + 10 - 'A';
+    if (ch >= 'a' && ch <= 'f')
+        return ch + 10 - 'a';
+    return -1;
+}
+
+void swapByteOrder(uint8_t* buf, int len)
+{
+    uint8_t* p1 = buf;
+    uint8_t* p2 = buf + len - 1;
+    while (p1 < p2)
+    {
+        uint8_t t = *p1;
+        *p1 = *p2;
+        *p2 = t;
+        p1++;
+        p2--;
+    }
+}