separate ISR handling from IRQ processing

examples/InterruptConfigure/InterruptConfigure.ino

@@ -19,6 +19,7 @@
 
 // We will be using the nRF24L01's IRQ pin for this example
 #define IRQ_PIN 2 // this needs to be a digital input capable pin
+volatile bool got_interrupt = false; // used to signal processing of interrupt
 volatile bool wait_for_event = false; // used to wait for an IRQ event to trigger
 
 #define CE_PIN 7
@@ -136,9 +137,11 @@ void setup() {
 }
 
 void loop() {
- if (role && !wait_for_event) {
+ if (got_interrupt) {
+ assessInterruptEvent();
+ }
 
-  // delay(1); // wait for IRQ pin to fully RISE
+ if (role && !wait_for_event) {
 
  // This device is a TX node. This if block is only triggered when
  // NOT waiting for an IRQ event to happen
@@ -218,25 +221,22 @@ void loop() {
  pl_iterator++; // proceed from step 3 to last step (stop at step 4 for readability)
  }
 
- } else if (!role) {
- // This device is a RX node
-
- if (radio.rxFifoFull()) {
- // wait until RX FIFO is full then stop listening
+ } else if (!role && radio.rxFifoFull()) {
+ // This device is a RX node:
+ // wait until RX FIFO is full then stop listening
 
-  delay(100); // let ACK payload finish transmitting
-  radio.stopListening(); // also discards unused ACK payloads
-  printRxFifo(); // flush the RX FIFO
+ delay(100); // let ACK payload finish transmitting
+ radio.stopListening(); // also discards unused ACK payloads
+ printRxFifo(); // flush the RX FIFO
 
-  // Fill the TX FIFO with 3 ACK payloads for the first 3 received
-  // transmissions on pipe 1.
-  radio.writeAckPayload(1, &ack_payloads[0], ack_pl_size);
-  radio.writeAckPayload(1, &ack_payloads[1], ack_pl_size);
-  radio.writeAckPayload(1, &ack_payloads[2], ack_pl_size);
+ // Fill the TX FIFO with 3 ACK payloads for the first 3 received
+ // transmissions on pipe 1.
+ radio.writeAckPayload(1, &ack_payloads[0], ack_pl_size);
+ radio.writeAckPayload(1, &ack_payloads[1], ack_pl_size);
+ radio.writeAckPayload(1, &ack_payloads[2], ack_pl_size);
 
- delay(100); // let TX node finish its role
- radio.startListening(); // We're ready to start over. Begin listening.
- }
+ delay(100); // let TX node finish its role
+ radio.startListening(); // We're ready to start over. Begin listening.
 
  } // role
 
@@ -271,6 +271,7 @@ void loop() {
  // Fill the TX FIFO with 3 ACK payloads for the first 3 received
  // transmissions on pipe 1
  radio.flush_tx(); // make sure there is room for 3 new ACK payloads
+ radio.flush_rx(); // make sure there is room for 3 incoming payloads
  radio.writeAckPayload(1, &ack_payloads[0], ack_pl_size);
  radio.writeAckPayload(1, &ack_payloads[1], ack_pl_size);
  radio.writeAckPayload(1, &ack_payloads[2], ack_pl_size);
@@ -281,9 +282,18 @@ void loop() {
 
 
 /**
- * when the IRQ pin goes active LOW, call this fuction print out why
+ * when the IRQ pin goes active LOW.
+ * Here we just tell the main loop() to call `assessInterruptEve4nt()`.
  */
 void interruptHandler() {
+ got_interrupt = true; // forward event handling back to main loop()
+}
+
+/**
+ * Called when an event has been triggered.
+ * Here, we want to verify the expected IRQ flag has been asserted.
+ */
+void assessInterruptEvent() {
  // print IRQ status and all masking flags' states
 
  Serial.println(F("\tIRQ pin is actively LOW")); // show that this function was called
@@ -316,9 +326,9 @@ void interruptHandler() {
  Serial.print(F(" 'Data Fail' event test "));
  Serial.println(tx_df ? F("passed") : F("failed"));
  }
+ got_interrupt = false; // reset this flag to prevent calling this function from loop()
  wait_for_event = false; // ready to continue with loop() operations
-} // interruptHandler
-
+}
 
 /**
  * Print the entire RX FIFO with one buffer. This will also flush the RX FIFO.

examples_linux/interruptConfigure.cpp

@@ -25,7 +25,7 @@ using namespace std;
 #define IRQ_PIN 12 // this needs to be a digital input capable pin
 
 // this example is a sequential program. so we need to wait for the event to be handled
-volatile bool wait_for_event = false; // used to signify that the event is handled
+volatile bool got_interrupt = false; // used to signify that the event started
 
 /****************** Linux ***********************/
 // Radio CE Pin, CSN Pin, SPI Speed
@@ -245,12 +245,12 @@ void slave()
  */
 void ping_n_wait()
 {
+ got_interrupt = false;
+
  // use the non-blocking call to write a payload and begin transmission
  // the "false" argument means we are expecting an ACK packet response
  radio.startFastWrite(tx_payloads[pl_iterator], tx_pl_size, false);
-
- wait_for_event = true;
- while (wait_for_event) {
+ while (!got_interrupt) {
  /*
  * IRQ pin is LOW when activated. Otherwise it is always HIGH
  * Wait in this empty loop until IRQ pin is activated.
@@ -260,13 +260,6 @@ void ping_n_wait()
  * default, we don't need a timeout check to prevent an infinite loop.
  */
  }
-}
-
-/**
- * when the IRQ pin goes active LOW, call this fuction print out why
- */
-void interruptHandler()
-{
  // print IRQ status and all masking flags' states
 
  cout << "\tIRQ pin is actively LOW" << endl; // show that this function was called
@@ -292,8 +285,17 @@ void interruptHandler()
  else if (pl_iterator == 3)
  cout << " 'Data Fail' event test " << (tx_df ? "passed" : "failed") << endl;
 
- wait_for_event = false; // ready to continue
-} // interruptHandler
+ got_interrupt = false;
+}
+
+/**
+ * when the IRQ pin goes active LOW.
+ * Here we just set a flag to unblock ping_n_wait()
+ */
+void interruptHandler()
+{
+ got_interrupt = true; // ready to continue
+}
 
 /**
  * Print the entire RX FIFO with one buffer. This will also flush the RX FIFO.

examples_pico/interruptConfigure.cpp

@@ -21,6 +21,7 @@
 
 // We will be using the nRF24L01's IRQ pin for this example
 volatile bool wait_for_event = false; // used to wait for an IRQ event to trigger
+volatile bool got_interrupt = false; // used to signal when an IRQ event has been triggered
 
 // instantiate an object for the nRF24L01 transceiver
 RF24 radio(CE_PIN, CSN_PIN);
@@ -40,6 +41,7 @@ char ack_payloads[][ack_pl_size + 1] = {"Yak ", "Back", " ACK"};
 
 void interruptHandler(uint gpio, uint32_t events); // prototype to handle IRQ events
 void printRxFifo(); // prototype to print RX FIFO with 1 buffer
+void assessInterruptEvent(); // prototype to assess IRQ flags triggered
 
 bool setup()
 {
@@ -121,7 +123,6 @@ bool setup()
  }
 
  // For debugging info
- // printf_begin(); // needed only once for printing details
  // radio.printDetails(); // (smaller) function that prints raw register values
  // radio.printPrettyDetails(); // (larger) function that prints human readable data
 
@@ -231,6 +232,10 @@ void loop()
 
  } // role
 
+ if (got_interrupt) {
+ assessInterruptEvent();
+ }
+
  char input = getchar_timeout_us(0); // get char from buffer for user input
  if (input != PICO_ERROR_TIMEOUT) {
  // change the role via the serial terminal
@@ -239,7 +244,7 @@ void loop()
  // Become the TX node
  if (!role)
  printf("*** CHANGING TO TRANSMIT ROLE -- PRESS 'R' TO SWITCH BACK\n");
- else if (role && wait_for_event) // don't interrupt on ongoing test
+ else if (role && wait_for_event) // don't interrupt an ongoing test
  return; // exit now; start next loop()
  else
  printf("*** RESTARTING IRQ PIN TEST ***\n");
@@ -277,16 +282,24 @@ void loop()
 } // loop
 
 /**
- * when the IRQ pin goes active LOW, call this fuction print out why
+ * when the IRQ pin goes active LOW.
+ * Here we just tell the main loop() to call `assessInterruptEve4nt()`.
  */
 void interruptHandler(uint gpio, uint32_t events)
 {
-
  if (gpio != IRQ_PIN && !(events | GPIO_IRQ_EDGE_FALL)) {
  // the gpio pin and event does not match the configuration we specified
  return;
  }
+ got_interrupt = true; // forward event handling back to main loop()
+}
 
+/**
+ * Called when an event has been triggered.
+ * Here, we want to verify the expected IRQ flag has been asserted.
+ */
+void assessInterruptEvent()
+{
  // print IRQ status and all masking flags' states
  printf("\tIRQ pin is actively LOW\n"); // show that this function was called
  bool tx_ds, tx_df, rx_dr; // declare variables for IRQ masks
@@ -315,8 +328,9 @@ void interruptHandler(uint gpio, uint32_t events)
  else if (pl_iterator == 4) {
  printf(" 'Data Fail' event test %s\n", tx_df ? "passed" : "failed");
  }
+ got_interrupt = false; // reset this flag to prevent calling this function from loop()
  wait_for_event = false; // ready to continue with loop() operations
-} // interruptHandler
+}
 
 /**
  * Print the entire RX FIFO with one buffer. This will also flush the RX FIFO.