the mountain of changes needed to kinda make tx work compiles.

docs/software/nrf52-TODO.md

@@ -47,6 +47,9 @@ Needed to be fully functional at least at the same level of the ESP32 boards. At
 
 ## Items to be 'feature complete'
 
+- figure out what the correct current limit should be for the sx1262, currently we just use the default 100
+- use SX126x::startReceiveDutyCycleAuto to save power by sleeping and briefly waking to check for preamble bits. Change xmit rules to have more preamble bits.
+- put sx1262 in sleepmode when processor gets shutdown (or rebooted), ideally even for critical faults (to keep power draw low). repurpose deepsleep state for this.
 - good power management tips: https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/optimizing-power-on-nrf52-designs
 - call PMU set_ADC_CONV(0) during sleep, to stop reading PMU adcs and decrease current draw
 - do final power measurements

src/rf95/CustomRF95.cpp

@@ -7,11 +7,7 @@
 
 #ifdef RF95_IRQ_GPIO
 
-/// A temporary buffer used for sending/receving packets, sized to hold the biggest buffer we might need
-#define MAX_RHPACKETLEN 251
-static uint8_t radiobuf[MAX_RHPACKETLEN];
-
-CustomRF95::CustomRF95() : RH_RF95(NSS_GPIO, RF95_IRQ_GPIO), txQueue(MAX_TX_QUEUE) {}
+CustomRF95::CustomRF95() : RH_RF95(NSS_GPIO, RF95_IRQ_GPIO) {}
 
 bool CustomRF95::canSleep()
 {
@@ -52,13 +48,11 @@ ErrorCode CustomRF95::send(MeshPacket *p)
     // We wait _if_ we are partially though receiving a packet (rather than just merely waiting for one).
     // To do otherwise would be doubly bad because not only would we drop the packet that was on the way in,
     // we almost certainly guarantee no one outside will like the packet we are sending.
-    if (_mode == RHModeIdle || (_mode == RHModeRx && !isReceiving())) {
+    if (_mode == RHModeIdle || !isReceiving()) {
         // if the radio is idle, we can send right away
         DEBUG_MSG("immediate send on mesh fr=0x%x,to=0x%x,id=%d\n (txGood=%d,rxGood=%d,rxBad=%d)\n", p->from, p->to, p->id,
                   txGood(), rxGood(), rxBad());
 
-        waitPacketSent(); // Make sure we dont interrupt an outgoing message
-
         if (!waitCAD())
             return false; // Check channel activity
 
@@ -159,29 +153,20 @@ void CustomRF95::handleIdleISR()
 /// This routine might be called either from user space or ISR
 void CustomRF95::startSend(MeshPacket *txp)
 {
-    assert(!sendingPacket);
-
-    // DEBUG_MSG("sending queued packet on mesh (txGood=%d,rxGood=%d,rxBad=%d)\n", rf95.txGood(), rf95.rxGood(), rf95.rxBad());
-    assert(txp->has_payload);
-
-    lastTxStart = millis();
-
-    size_t numbytes = pb_encode_to_bytes(radiobuf, sizeof(radiobuf), SubPacket_fields, &txp->payload);
-
-    sendingPacket = txp;
+    size_t numbytes = beginSending(txp);
 
     setHeaderTo(txp->to);
     setHeaderId(txp->id);
 
     // if the sender nodenum is zero, that means uninitialized
-    assert(txp->from);
     setHeaderFrom(txp->from); // We must do this before each send, because we might have just changed our nodenum
 
     assert(numbytes <= 251); // Make sure we don't overflow the tiny max packet size
 
     // uint32_t start = millis(); // FIXME, store this in the class
 
-    int res = RH_RF95::send(radiobuf, numbytes);
+    // This legacy implementation doesn't use our inserted packet header
+    int res = RH_RF95::send(radiobuf + sizeof(PacketHeader), numbytes - sizeof(PacketHeader));
     assert(res);
 }
 

src/rf95/CustomRF95.h

@@ -13,10 +13,6 @@ class CustomRF95 : public RH_RF95, public RadioInterface
 {
     friend class MeshRadio; // for debugging we let that class touch pool
 
-    PointerQueue<MeshPacket> txQueue;
-
-    uint32_t lastTxStart = 0L;
-
   public:
     /** pool is the pool we will alloc our rx packets from
      * rxDest is where we will send any rx packets, it becomes receivers responsibility to return packet to the pool

src/rf95/RadioInterface.cpp

@@ -6,7 +6,10 @@
 #include <pb_decode.h>
 #include <pb_encode.h>
 
-RadioInterface::RadioInterface() {}
+RadioInterface::RadioInterface() : txQueue(MAX_TX_QUEUE)
+{
+    assert(sizeof(PacketHeader) == 4); // make sure the compiler did what we expected
+}
 
 ErrorCode SimRadio::send(MeshPacket *p)
 {
@@ -21,3 +24,32 @@ void RadioInterface::deliverToReceiver(MeshPacket *p)
     assert(rxDest->enqueue(p, 0)); // NOWAIT - fixme, if queue is full, delete older messages
 }
 
+/***
+ * given a packet set sendingPacket and decode the protobufs into radiobuf.  Returns # of payload bytes to send
+ */
+size_t RadioInterface::beginSending(MeshPacket *p)
+{
+    assert(!sendingPacket);
+
+    // DEBUG_MSG("sending queued packet on mesh (txGood=%d,rxGood=%d,rxBad=%d)\n", rf95.txGood(), rf95.rxGood(), rf95.rxBad());
+    assert(p->has_payload);
+
+    lastTxStart = millis();
+
+    PacketHeader *h = (PacketHeader *)radiobuf;
+
+    h->from = p->from;
+    h->to = p->to;
+    h->flags = 0;
+    h->id = p->id;
+
+    // if the sender nodenum is zero, that means uninitialized
+    assert(h->from);
+
+    size_t numbytes = pb_encode_to_bytes(radiobuf + sizeof(PacketHeader), sizeof(radiobuf), SubPacket_fields, &p->payload) + sizeof(PacketHeader);
+
+    assert(numbytes <= MAX_RHPACKETLEN);
+
+    sendingPacket = p;
+    return numbytes;
+}

src/rf95/RadioInterface.h

@@ -8,6 +8,18 @@
 
 #define MAX_TX_QUEUE 16 // max number of packets which can be waiting for transmission
 
+#define MAX_RHPACKETLEN 256
+
+/**
+ * This structure has to exactly match the wire layout when sent over the radio link.  Used to keep compatibility 
+ * wtih the old radiohead implementation.
+ */
+typedef struct {
+    uint8_t to, from, id, flags;
+} PacketHeader;
+
+
+
 /**
  * Basic operations all radio chipsets must implement.
  *
@@ -20,6 +32,13 @@ class RadioInterface
 
   protected:
     MeshPacket *sendingPacket = NULL; // The packet we are currently sending
+    PointerQueue<MeshPacket> txQueue;
+    uint32_t lastTxStart = 0L;
+
+    /**
+     * A temporary buffer used for sending/receving packets, sized to hold the biggest buffer we might need
+     * */
+    uint8_t radiobuf[MAX_RHPACKETLEN];
 
     /**
      * Enqueue a received packet for the registered receiver
@@ -82,6 +101,14 @@ class RadioInterface
     /// Make sure the Driver is properly configured before calling init().
     /// \return true if initialisation succeeded.
     virtual bool reconfigure() = 0;
+
+  protected:
+    /***
+     * given a packet set sendingPacket and decode the protobufs into radiobuf.  Returns # of bytes to send (including the PacketHeader & payload).
+     * 
+     * Used as the first step of 
+     */
+    size_t beginSending(MeshPacket *p);
 };
 
 class SimRadio : public RadioInterface

src/rf95/RadioLibInterface.cpp

@@ -8,8 +8,26 @@ RadioLibInterface::RadioLibInterface(RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq
                                      SPIClass &spi, PhysicalLayer *_iface)
     : module(cs, irq, rst, busy, spi, spiSettings), iface(*_iface)
 {
+    assert(!instance); // We assume only one for now
+    instance = this;
 }
 
+void INTERRUPT_ATTR RadioLibInterface::isrRxLevel0()
+{
+    instance->pending = ISR_RX;
+    instance->disableInterrupt();
+}
+
+void INTERRUPT_ATTR RadioLibInterface::isrTxLevel0()
+{
+    instance->pending = ISR_TX;
+    instance->disableInterrupt();
+}
+
+/** Our ISR code currently needs this to find our active instance
+ */
+RadioLibInterface *RadioLibInterface::instance;
+
 /**
  * Convert our modemConfig enum into wf, sf, etc...
  */
@@ -41,9 +59,144 @@ void RadioLibInterface::applyModemConfig()
     }
 }
 
+/// Send a packet (possibly by enquing in a private fifo).  This routine will
+/// later free() the packet to pool.  This routine is not allowed to stall because it is called from
+/// bluetooth comms code.  If the txmit queue is empty it might return an error
 ErrorCode RadioLibInterface::send(MeshPacket *p)
 {
-    return ERR_NONE;
+    // We wait _if_ we are partially though receiving a packet (rather than just merely waiting for one).
+    // To do otherwise would be doubly bad because not only would we drop the packet that was on the way in,
+    // we almost certainly guarantee no one outside will like the packet we are sending.
+    if (canSendImmediately()) {
+        // if the radio is idle, we can send right away
+        DEBUG_MSG("immediate send on mesh fr=0x%x,to=0x%x,id=%d\n (txGood=%d,rxGood=%d,rxBad=%d)\n", p->from, p->to, p->id, -1,
+                  -1, -1);
+
+        startSend(p);
+        return ERRNO_OK;
+    } else {
+        DEBUG_MSG("enqueuing packet for send from=0x%x, to=0x%x\n", p->from, p->to);
+        ErrorCode res = txQueue.enqueue(p, 0) ? ERRNO_OK : ERRNO_UNKNOWN;
+
+        if (res != ERRNO_OK) // we weren't able to queue it, so we must drop it to prevent leaks
+            packetPool.release(p);
+
+        return res;
+    }
+}
+
+void RadioLibInterface::loop()
+{
+    PendingISR wasPending = pending; // atomic read
+    if (wasPending) {
+        pending = ISR_NONE; // If the flag was set, it is _guaranteed_ the ISR won't be running, because it masked itself
+
+        if (wasPending == ISR_TX)
+            handleTransmitInterrupt();
+        else if (wasPending == ISR_RX)
+            handleReceiveInterrupt();
+        else
+            assert(0);
+
+        // First send any outgoing packets we have ready
+        MeshPacket *txp = txQueue.dequeuePtr(0);
+        if (txp)
+            startSend(txp);
+        else {
+            // Nothing to send, let's switch back to receive mode
+            // FIXME - RH_RF95::setModeRx();
+        }
+    }
+}
+
+void RadioLibInterface::handleTransmitInterrupt()
+{
+    assert(sendingPacket); // Were we sending?
+
+    // FIXME - check result code from ISR
+
+    // We are done sending that packet, release it
+    packetPool.release(sendingPacket);
+    sendingPacket = NULL;
+    // DEBUG_MSG("Done with send\n");
+}
+
+void RadioLibInterface::handleReceiveInterrupt()
+{
+    // FIXME
+}
+
+#if 0
+// After doing standard behavior, check to see if a new packet arrived or one was sent and start a new send or receive as
+// necessary
+void CustomRF95::handleInterrupt()
+{
+    RH_RF95::handleInterrupt();
+    enableInterrupt(); // Let ISR run again
+
+    if (_mode == RHModeIdle) // We are now done sending or receiving
+    {
+
+        // If we just finished receiving a packet, forward it into a queue
+        if (_rxBufValid) {
+            // We received a packet
+
+            // Skip the 4 headers that are at the beginning of the rxBuf
+            size_t payloadLen = _bufLen - RH_RF95_HEADER_LEN;
+            uint8_t *payload = _buf + RH_RF95_HEADER_LEN;
+
+            // FIXME - throws exception if called in ISR context: frequencyError() - probably the floating point math
+            int32_t freqerr = -1, snr = lastSNR();
+            // DEBUG_MSG("Received packet from mesh src=0x%x,dest=0x%x,id=%d,len=%d rxGood=%d,rxBad=%d,freqErr=%d,snr=%d\n",
+            //          srcaddr, destaddr, id, rxlen, rf95.rxGood(), rf95.rxBad(), freqerr, snr);
+
+            MeshPacket *mp = packetPool.allocZeroed();
+
+            SubPacket *p = &mp->payload;
+
+            mp->from = _rxHeaderFrom;
+            mp->to = _rxHeaderTo;
+            mp->id = _rxHeaderId;
+
+            //_rxHeaderId = _buf[2];
+            //_rxHeaderFlags = _buf[3];
+
+            // If we already have an entry in the DB for this nodenum, goahead and hide the snr/freqerr info there.
+            // Note: we can't create it at this point, because it might be a bogus User node allocation.  But odds are we will
+            // already have a record we can hide this debugging info in.
+            NodeInfo *info = nodeDB.getNode(mp->from);
+            if (info) {
+                info->snr = snr;
+                info->frequency_error = freqerr;
+            }
+
+            if (!pb_decode_from_bytes(payload, payloadLen, SubPacket_fields, p)) {
+                packetPool.release(mp);
+            } else {
+                // parsing was successful, queue for our recipient
+                mp->has_payload = true;
+
+                deliverToReceiver(mp);
+            }
+
+            clearRxBuf(); // This message accepted and cleared
+        }
+
+        handleIdleISR();
+    }
+}
+#endif
+
+/** start an immediate transmit */
+void RadioLibInterface::startSend(MeshPacket *txp)
+{
+    size_t numbytes = beginSending(txp);
+
+    int res = iface.startTransmit(radiobuf, numbytes);
+    assert(res);
+
+    // Must be done AFTER, starting transmit, because startTransmit clears (possibly stale) interrupt pending register bits
+    enableInterrupt(isrTxLevel0);
 }
 
 /**
@@ -53,39 +206,178 @@ ErrorCode RadioLibInterface::send(MeshPacket *p)
 // include the library
 
 
+// save transmission state between loops
+int transmissionState = ERR_NONE;
 
-void loop() {
-  Serial.print(F("[SX1262] Transmitting packet ... "));
+void setup() {
+  Serial.begin(9600);
+
+  // initialize SX1262 with default settings
+  Serial.print(F("[SX1262] Initializing ... "));
+  // carrier frequency:           434.0 MHz
+  // bandwidth:                   125.0 kHz
+  // spreading factor:            9
+  // coding rate:                 7
+  // sync word:                   0x12 (private network)
+  // output power:                14 dBm
+  // current limit:               60 mA
+  // preamble length:             8 symbols
+  // TCXO voltage:                1.6 V (set to 0 to not use TCXO)
+  // regulator:                   DC-DC (set to true to use LDO)
+  // CRC:                         enabled
+  int state = lora.begin();
+  if (state == ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+
+  // set the function that will be called
+  // when packet transmission is finished
+  lora.setDio1Action(setFlag);
+
+  // start transmitting the first packet
+  Serial.print(F("[SX1262] Sending first packet ... "));
 
   // you can transmit C-string or Arduino string up to
   // 256 characters long
-  // NOTE: transmit() is a blocking method!
-  //       See example SX126x_Transmit_Interrupt for details
-  //       on non-blocking transmission method.
-  int state = lora.transmit("Hello World!");
+  transmissionState = lora.startTransmit("Hello World!");
 
   // you can also transmit byte array up to 256 bytes long
 
-    byte byteArr[] = {0x01, 0x23, 0x45, 0x56, 0x78, 0xAB, 0xCD, 0xEF};
-    int state = lora.transmit(byteArr, 8);
+    byte byteArr[] = {0x01, 0x23, 0x45, 0x67,
+                      0x89, 0xAB, 0xCD, 0xEF};
+    state = lora.startTransmit(byteArr, 8);
+
+}
+
+// flag to indicate that a packet was sent
+volatile bool transmittedFlag = false;
+
+// disable interrupt when it's not needed
+volatile bool enableInterrupt = true;
+
+// this function is called when a complete packet
+// is transmitted by the module
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+void setFlag(void)
+{
+    // check if the interrupt is enabled
+    if (!enableInterrupt) {
+        return;
+    }
+
+    // we sent a packet, set the flag
+    transmittedFlag = true;
+}
+
+void loop()
+{
+    // check if the previous transmission finished
+    if (transmittedFlag) {
+        // disable the interrupt service routine while
+        // processing the data
+        enableInterrupt = false;
+
+        // reset flag
+        transmittedFlag = false;
+
+        if (transmissionState == ERR_NONE) {
+            // packet was successfully sent
+            Serial.println(F("transmission finished!"));
+
+            // NOTE: when using interrupt-driven transmit method,
+            //       it is not possible to automatically measure
+            //       transmission data rate using getDataRate()
+
+        } else {
+            Serial.print(F("failed, code "));
+            Serial.println(transmissionState);
+        }
+
+        // wait a second before transmitting again
+        delay(1000);
+
+        // send another one
+        Serial.print(F("[SX1262] Sending another packet ... "));
+
+        // you can transmit C-string or Arduino string up to
+        // 256 characters long
+        transmissionState = lora.startTransmit("Hello World!");
+
+        // you can also transmit byte array up to 256 bytes long
+
+          byte byteArr[] = {0x01, 0x23, 0x45, 0x67,
+                            0x89, 0xAB, 0xCD, 0xEF};
+          int state = lora.startTransmit(byteArr, 8);
+
+
+// we're ready to send more packets,
+// enable interrupt service routine
+enableInterrupt = true;
+}
+}
+
+// this function is called when a complete packet
+// is received by the module
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+void setFlag(void)
+{
+    // check if the interrupt is enabled
+    if (!enableInterrupt) {
+        return;
+    }
+
+    // we got a packet, set the flag
+    receivedFlag = true;
+}
+
+void loop()
+{
+    // check if the flag is set
+    if (receivedFlag) {
+        // disable the interrupt service routine while
+        // processing the data
+        enableInterrupt = false;
+
+        // reset flag
+        receivedFlag = false;
+
+        // you can read received data as an Arduino String
+        String str;
+        int state = lora.readData(str);
+
+        // you can also read received data as byte array
+
+          byte byteArr[8];
+          int state = lora.readData(byteArr, 8);
 
 
 if (state == ERR_NONE) {
-    // the packet was successfully transmitted
-    Serial.println(F("success!"));
+    // packet was successfully received
+    Serial.println(F("[SX1262] Received packet!"));
 
-    // print measured data rate
-    Serial.print(F("[SX1262] Datarate:\t"));
-    Serial.print(lora.getDataRate());
-    Serial.println(F(" bps"));
+    // print data of the packet
+    Serial.print(F("[SX1262] Data:\t\t"));
+    Serial.println(str);
 
-} else if (state == ERR_PACKET_TOO_LONG) {
-    // the supplied packet was longer than 256 bytes
-    Serial.println(F("too long!"));
+    // print RSSI (Received Signal Strength Indicator)
+    Serial.print(F("[SX1262] RSSI:\t\t"));
+    Serial.print(lora.getRSSI());
+    Serial.println(F(" dBm"));
 
-} else if (state == ERR_TX_TIMEOUT) {
-    // timeout occured while transmitting packet
-    Serial.println(F("timeout!"));
+    // print SNR (Signal-to-Noise Ratio)
+    Serial.print(F("[SX1262] SNR:\t\t"));
+    Serial.print(lora.getSNR());
+    Serial.println(F(" dB"));
+
+} else if (state == ERR_CRC_MISMATCH) {
+    // packet was received, but is malformed
+    Serial.println(F("CRC error!"));
 
 } else {
     // some other error occurred
@@ -93,7 +385,12 @@ if (state == ERR_NONE) {
     Serial.println(state);
 }
 
-// wait for a second before transmitting again
-delay(1000);
+// put module back to listen mode
+lora.startReceive();
+
+// we're ready to receive more packets,
+// enable interrupt service routine
+enableInterrupt = true;
 }
- */
+}
+*/

src/rf95/RadioLibInterface.h

@@ -4,8 +4,30 @@
 
 #include <RadioLib.h>
 
+// ESP32 has special rules about ISR code
+#ifdef ARDUINO_ARCH_ESP32
+#define INTERRUPT_ATTR IRAM_ATTR
+#else
+#define INTERRUPT_ATTR
+#endif
+
 class RadioLibInterface : public RadioInterface
 {
+    enum PendingISR { ISR_NONE = 0, ISR_RX, ISR_TX };
+
+    /**
+     * What sort of interrupt do we expect our helper thread to now handle */
+    volatile PendingISR pending;
+
+    /** Our ISR code currently needs this to find our active instance
+     */
+    static RadioLibInterface *instance;
+
+    /**
+     * Raw ISR handler that just calls our polymorphic method
+     */
+    static void isrRxLevel0(), isrTxLevel0();
+
   protected:
     float bw = 125;
     uint8_t sf = 9;
@@ -27,6 +49,16 @@ class RadioLibInterface : public RadioInterface
      */
     PhysicalLayer &iface;
 
+    /**
+     * Glue functions called from ISR land
+     */
+    virtual void disableInterrupt() = 0;
+
+    /**
+     * Enable a particular ISR callback glue function
+     */
+    virtual void enableInterrupt(void (*)()) = 0;
+
   public:
     RadioLibInterface(RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst, RADIOLIB_PIN_TYPE busy, SPIClass &spi,
                       PhysicalLayer *iface);
@@ -51,9 +83,20 @@ class RadioLibInterface : public RadioInterface
     /// \return true if initialisation succeeded.
     virtual bool init() { return true; }
 
+    virtual void loop(); // Idle processing
+
   protected:
     /**
      * Convert our modemConfig enum into wf, sf, etc...
      */
     void applyModemConfig();
+
+    /** Could we send right now (i.e. either not actively receiving or transmitting)? */
+    virtual bool canSendImmediately() = 0;
+
+    /** start an immediate transmit */
+    void startSend(MeshPacket *txp);
+
+    void handleTransmitInterrupt();
+    void handleReceiveInterrupt();
 };

src/rf95/SX1262Interface.cpp

@@ -27,6 +27,9 @@ bool SX1262Interface::init()
     int res = lora.begin(freq, bw, sf, cr, syncWord, power, currentLimit, preambleLength, tcxoVoltage, useRegulatorLDO);
     DEBUG_MSG("LORA init result %d\n", res);
 
+    if (res != ERR_NONE)
+        res = lora.setCRC(SX126X_LORA_CRC_ON);
+
     return res == ERR_NONE;
 }
 
@@ -69,3 +72,19 @@ bool SX1262Interface::reconfigure()
 
     return true;
 }
+
+/** Could we send right now (i.e. either not actively receving or transmitting)? */
+bool SX1262Interface::canSendImmediately()
+{
+    return true; // FIXME
+#if 0
+    // We wait _if_ we are partially though receiving a packet (rather than just merely waiting for one).
+    // To do otherwise would be doubly bad because not only would we drop the packet that was on the way in,
+    // we almost certainly guarantee no one outside will like the packet we are sending.
+    if (_mode == RHModeIdle || isReceiving()) {
+        // if the radio is idle, we can send right away
+        DEBUG_MSG("immediate send on mesh fr=0x%x,to=0x%x,id=%d\n (txGood=%d,rxGood=%d,rxBad=%d)\n", p->from, p->to, p->id,
+                  txGood(), rxGood(), rxBad());
+    }
+#endif 
+}

src/rf95/SX1262Interface.h

@@ -18,4 +18,18 @@ class SX1262Interface : public RadioLibInterface
     /// Make sure the Driver is properly configured before calling init().
     /// \return true if initialisation succeeded.
     virtual bool reconfigure();
+
+  protected:
+    /**
+     * Glue functions called from ISR land
+     */
+    virtual void INTERRUPT_ATTR disableInterrupt() { lora.clearDio1Action(); }
+
+    /**
+     * Enable a particular ISR callback glue function
+     */
+    virtual void enableInterrupt(void (*callback)()) { lora.setDio1Action(callback); }
+
+    /** Could we send right now (i.e. either not actively receiving or transmitting)? */
+    virtual bool canSendImmediately();
 };