BrendonHills
commented
4 years ago Apologies, I forgot to post the receiver code which receives the ASCII value of the integers sent by the transmitter. The integer 0 is sent for water LOW, 1 for water HIGH, 2 for good battery and 3 for recharge battery. If it becomes reliable, then I would add output via digital pins according to the switch case.
`#include
include
define RFM95_CS 8
define RFM95_RST 4
define RFM95_INT 7
void setup() { LoRa.setPins(RFM95_CS, RFM95_RST, RFM95_INT); Serial.begin(9600); while (!Serial);
Serial.println("LoRa Receiver");
if (!LoRa.begin(868E6)) { Serial.println("Starting LoRa failed!"); while (1); } LoRa.setTxPower(20); LoRa.enableCrc(); //prevent bad packets }
void loop() { // try to parse packet int packetSize = LoRa.parsePacket(); if (packetSize) { // received a packet Serial.print("Received packet ");
// read packet
while (LoRa.available()) {
int message = ((char)LoRa.read());
switch (message) {
case 48:
Serial.println("Water LOW");
break;
case 49:
Serial.println("Water HIGH");
break;
case 50:
Serial.println("Health OK");
break;
case 51:
Serial.println("Recharge battery");
break;
}
}
// print RSSI of packet
//Serial.print("' with RSSI ");
//Serial.println(LoRa.packetRssi());} }`
IoTThinks
beowulff
Please can I have some advice? I am using Adafruit 32u4 Feather RFM95 LoRa boards and I have written code which uses two interrupts to wake from sleep, first on the activation of a RTC alarm (DS3231 Feather Board) and second on the activation of a change in a water sensor (for now simulated by a simple switch.) I have modularly tested to destruction every bit of code for the RTC, water sensor and sleep and all seems to work perfectly. The problem comes when I add the LoRa basic sender and receiver example code as functions called as a result of the ISR. I receive many erratic false packets giving sensor readings that have just NOT happened! I have narrowed it down to the LoRa receive module, and have done so by variously preventing the interrupts, and, at one point even disconnecting the transmitter, just leaving the receiver running, still receiving false packets. To be sure, I uploaded the basic examples of code from the library alone and without modification to the boards. Same issue, only this time instead of getting false activations (water high, water low, etc) I get spurious gibberish symbols and on receive only - see first image. I then suspected RFI, or perhpaps interference over the usb cable. So, I added ferrite cores to the (shielded) usb cable and wrapped the receiver in tin foil (apart from the antenna) to act as a Farday cage. Still the problem persists. I even ruled out faulty boards - if I upload the example basic RadioHead code to both boards it runs for days absolutely perfectly with no false packets. So I believe the issue MUST be in the LoRa receive code or library. Am I right, and if so, why? Please help if you can, I have spent over two weeks on this single issue and on Google but can't spot the problem any deeper. I would use the RadioHead library instead, but this one is so much simpler and neater for someone as relatively inexperienced as me - I want to make it work! Code is below and I attach a screenshot of spurious packets. My thanks in advance - all help greatly appreciated.
`//Initialisation ==============================================
//for battery voltage ============
define VBATPIN A9
float measuredvbat; int healthCheck;
// For the RTC ===========
include "Wire.h"
include "RTClibExtended.h"
define RTCwakePin 1
volatile bool clockAlarm = false; RTC_DS3231 RTC;
// For Sleep mode ===========
include "LowPower.h"
// For the sensor =============
define sensorWakePin 0
int waterLevel; volatile bool sensorAlarm = false; volatile int valA; int waterLevelSent;
// For LoRa ============
include
include
define RFM95_CS 8
define RFM95_RST 4
define RFM95_INT 7
void setup() {
// For the RTC ==================================================== pinMode(RTCwakePin, INPUT_PULLUP); //Initialize communication with the clock Wire.begin(); RTC.begin(); // dECIDE IF TO LEAVE THE BELOW OR REMOVE - NEED TO SET RTC SEPERATELY IF REMOVED //RTC.adjust(DateTime(DATE, TIME)); //set RTC date and time to COMPILE time //Set SQW pin to OFF RTC.writeSqwPinMode(DS3231_OFF); initiateAlarm(); //call fn to clear and set alarms //Set alarm1 every day at 09:00 - minutes first then hour, 0 for secs no account of daylight saving time //RTC.setAlarm(ALM1_MATCH_HOURS, 0, 0, 09, 0); //Set alarm1 at 1 min past the hour past the minute REMOVE IN FINAL RTC.setAlarm(ALM1_MATCH_MINUTES, 0, 01, 0, 0);///REMOVE IN FINAL
// For the Water Sensor ==================================== pinMode(sensorWakePin, INPUT_PULLUP);
// For LoRa =============================== LoRa.setPins(RFM95_CS, RFM95_RST, RFM95_INT); //433E6 or 868E6 // Change sync word (0xF3)ranges from 0-0xFF //LoRa.setSyncWord(0xF3);
while (!LoRa.begin(868E6)) { ; } LoRa.setTxPower(20); LoRa.enableCrc(); //prevent bad packets //Set Spreading Factor to 12 for more robust, yet slowest signal //LoRa.setSpreadingFactor(12); //Set coding rate for best signal immunity - range 5 - 8 - default 5 8 doubles TX time!! //LoRa.setCodingRate4(8); //LoRa.setSignalBandwidth(); }
void RTCWakeUp() { clockAlarm = true; }
void sensorWakeUp() { valA = digitalRead(sensorWakePin); sensorAlarm = true; }
void loop() { USBDevice.attach();//remove in final
// rtc interrupt response if (clockAlarm) { clockAlarm = !clockAlarm; //reset flag initiateAlarm(); measuredvbat = analogRead(VBATPIN); measuredvbat = 2; // we divided by 2, so multiply back measuredvbat = 3.3; // Multiply by 3.3V, our reference voltage measuredvbat /= 1024; // convert to voltage if (measuredvbat >= 3.4) { healthCheck = 2; } else { healthCheck = 3; } LORATXHealth(); }
// sensor interrupt response if (sensorAlarm) { sensorAlarm = !sensorAlarm;// reset flag sensorDebounce(); //only send packet via Lora if there has been a change to water level since last packet sent if ((waterLevel) != (waterLevelSent)) { LORATXSensor(); } }
// once dealt with interrupts, can go back to sleep goToSleep(); }
void goToSleep() { noInterrupts(); attachInterrupt(digitalPinToInterrupt(sensorWakePin), sensorWakeUp, CHANGE); attachInterrupt(digitalPinToInterrupt(RTCwakePin), RTCWakeUp, FALLING); //LoRa sleep??? interrupts(); LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF); //Disable external pin interrupts on wake up detachInterrupt(digitalPinToInterrupt(RTCwakePin)); detachInterrupt(digitalPinToInterrupt(sensorWakePin)); }
void initiateAlarm() { //clear any pending alarms and reset RTC.armAlarm(1, false); RTC.clearAlarm(1); RTC.alarmInterrupt(1, false); RTC.armAlarm(2, false); RTC.clearAlarm(2); RTC.alarmInterrupt(2, false); RTC.alarmInterrupt(1, true);//reset }
void sensorDebounce() { //not really debounce. Just checking if water level is the same 3 secs later and only take action if so. delay(3000); int valB = digitalRead(sensorWakePin); if ((valA) != (valB)) {//tried surrounding this with 'noInterrupts' to preserve the volatile 'valA' but no effect goToSleep(); } else { waterLevel = !valB; } }
void LORATXHealth() { noInterrupts(); LoRa.beginPacket(); LoRa.print(healthCheck);//state of battery, 3 = OK, 4 = re-charge LoRa.endPacket(); //LORASLEEP?? if so need to wake on interrupt //what about an acknowledgement or re-send? interrupts(); }
void LORATXSensor() { noInterrupts(); LoRa.beginPacket(); LoRa.print(waterLevel); LoRa.endPacket(); waterLevelSent = waterLevel; //LORASLEEP?? if so need to wake on interrupt //what about an acknowledgement or re-send? interrupts(); }` This first image shows the spurious packets when just running the example code.
This second image shows the spurious packets form my code at the receiver - all the entries from 20:22:30.730 are entirely spurious and I am convinced did not come from the transmitting code.