I have tried to use pin based interrupts before. Was working on an anemometer (wind speed), The device pulsed 8 times per rotation. I was trying to count pulses over time, but the interrupt would never catch. I ended up removing the library and code for my I2C_LCD and the interrupt worked. Not sure what in the LCD code was the problem, I was not calling any of it from the interrupt routine.
I am now working on an Arduino controller for a small radio transmitter. It has a pin that goes low when the radio senses a signal. I have tried to use that to make sure I don't try to transmit when someone else is. Right now, all I am doing, for testing, is turning on an LED to show that there is a signal. I know there are easier ways to do this but right now, I am testing the interrupt feature.
/*
debug.ino
A simple sketch that configure a DRA818V and scan all the frequencies in the
range 134-174 MHz with a step of 12.5 kHz. 3 pins of the arduino are
used (PD, RX and TX) (CAUTION the DRA818 runs @3.3v). Configure the 3 macros
and customize the DRA818::configure(...) call to your needs.
Define the macro DRA818_DEBUG in DRA818.h and recompile to activate the
debug functions of the library.
Here is a sample output from the serial connection:
Booting ...
initializing I/O ... done
initializing DRA818 ... DRA818: log serial connection active
DRA818::handshake
-> AT+DMOCONNECT
<- +DMOCONNECT:0
Returned value=1
DRA818::group
-> AT+DMOSETGROUP=0,145.5000,145.5000,0000,4,0000
<- +DMOSETGROUP:0
Returned value=1
DRA818::volume
-> AT+DMOSETVOLUME=8
<- +DMOSETVOLUME:0
Returned value=1
DRA818::filters
-> AT+SETFILTER=1,1,1
<- +DMOSETFILTER:0
Returned value=1
done
Starting ...
Scanning frequency 134.0000 kHz ...DRA818::scan
-> S+134.0000
<- S=1
Returned value=0
Scanning frequency 134.0125 kHz ...DRA818::scan
-> S+134.0125
<- S=1
Returned value=0
I'm using a digital pin (D10) to crontrol the PD pin of the DRA818.
It's not mandatory, you can just let the PD pin of the DRA818
to HIGH and free an arduino digital pin.
Copyright (c) 2017, Jerome LOYET
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <SoftwareSerial.h>
#include "DRA818.h" // uncomment the following line in DRA818.h (#define DRA818_DEBUG)
/* Used Pins */
#define SIG 2 // Indicates signal is being received
#define PD 7 // to the DRA818 PD pin
#define RX 3 // arduino serial RX pin to the DRA818 TX pin
#define TX 4 // arduino serial TX pin to the DRA818 RX pin
#define PTT 5 // PTT pin
#define TONE 8 // makes tone to transmit
#define LED 9 // LED to show signal being received (pin SIG)
bool tx = false;
float freq;
void txon();
void txoff();
int stime;
SoftwareSerial *dra_serial; // Serial connection to DRA818
DRA818 *dra; // the DRA object once instanciated
// the next frequency to scan
void setup(){
Serial.begin(9600); // for logging
Serial.println("Booting ...");
Serial.print("initializing I/O ... ");
dra_serial = new SoftwareSerial(RX, TX); // Instantiate the Software Serial Object.
Serial.println("done"); // Power control of the DRA818
pinMode(PD, OUTPUT); // sleep pin
digitalWrite(PD,HIGH); // Set to not sleep
pinMode(PTT, OUTPUT); // Push to talk
digitalWrite(PTT, HIGH); // Set to receive
pinMode(SIG, INPUT);
pinMode(LED, OUTPUT); // LED signaling a signal being received
digitalWrite(LED, tx);
Serial.print("initializing DRA818 ... ");
/*
* Configure DRA818V using 145.500 MHz, squelch 4, volume 8, no ctcss, 12.5 kHz bandwidth, all filters activated
* We add the &Serial parameter to tell the DRA object where to log its debug information (to the builtin serial)
*
* Alternative call:
* dra = new DRA818(dra_serial, DRA818_VHF);
* dra->set_log(&Serial);
* dra->handshake();
* dra->group(DRA818_12K5, 145.500, 145.500, 0, 4, 0);
* dra->volume(8);
* dra->filters(true, true, true);
*/
dra = DRA818::configure(dra_serial, DRA818_VHF, 145.500, 145.500, 4, 8, 0, 0, DRA818_12K5, true, true, true, &Serial);
if (!dra) {
Serial.println("\nError while configuring DRA818");
}
freq = DRA818_VHF_MIN;
Serial.println("done");
Serial.println("Starting ... ");
delay(500);
pinMode(LED_BUILTIN, OUTPUT);
attachInterrupt(digitalPinToInterrupt(SIG), txon, FALLING);
attachInterrupt(digitalPinToInterrupt(SIG), txoff, RISING);
}
void loop(){
char buf[9];
if (!dra) return; // do nothing if DRA configuration failed
digitalWrite(PTT, LOW);
digitalWrite(LED_BUILTIN, HIGH);
delay(500);
tone(TONE,700);
delay(3000);
digitalWrite(PTT, HIGH);
noTone(TONE);
digitalWrite(LED_BUILTIN, LOW);
delay(5000);
stime = millis();
while (stime + 5000 > millis())
{
delay(500);
Serial.print("signal line is: ");
// Serial.println(digitalRead(SIG));
Serial.println(tx);
}
//dtostrf(freq, 8, 4, buf); // convert frequency to string with right precision
//Serial.print(String("Scanning frequency ") + String(buf) + String(" kHz ..."));
/* scan the frequency */
//if (dra->scan(freq)) Serial.print("Found");
//Serial.println("");
//freq += 0.0125; //12.5kHz step
//if (freq > DRA818_VHF_MAX) freq = DRA818_VHF_MIN; // when DRA818_VHF_MAX (174.0) is reached, start over at DRA818_VHF_MIN (134.0)
}
void txon()
{
tx = true;
digitalWrite(LED, tx);
}
void txoff()
{
tx = false;
digitalWrite(LED, tx);
}
Thus why bother with all that stuff...