E22 channel scanner needs help

Tagged: channel scanning, E22-900T30D, esp32

This topic has 6 replies, 2 voices, and was last updated 1 year, 6 months ago by Renzo Mischianti.

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13 March 2024 at 20:25 #30035

Participant

I want to scan LoRa frequencies to choose a low traffic channel for a LoRaWAN. sendTester.ino below sends a transparent mode message on channel 0x23 every second and scanner.ino listens cycling through a small range of channels that includes 0x23. It reports channels with non-zero rssi values.

The problem is that scanner.ino hears a few consecutive (5 – 10) messages on 0x23 but then goes deaf. I’m baffled. Is a buffer overflowing?

sendTest.ino

/*
* sends a message on channel 23 at 1 second intervals
*/

#include "Arduino.h"
#include "LoRa_E22.h"

// ---------- esp32 pins --------------
LoRa_E22 e22ttl(&Serial2, 15, 21, 19); // RX AUX M0 M1

void setup() {
Serial.begin(9600);
delay(500);

// Startup all pins and UART
e22ttl.begin();

// If you have ever change configuration you must restore It
ResponseStructContainer c;
c = e22ttl.getConfiguration();
Configuration configuration = *(Configuration*) c.data;
Serial.println(c.status.getResponseDescription());
configuration.ADDL = 0x03;
configuration.ADDH = 0x00;
configuration.NETID = 0x00;

configuration.CHAN = 0x23;

configuration.SPED.uartBaudRate = UART_BPS_9600;
configuration.SPED.airDataRate = AIR_DATA_RATE_010_24;
configuration.SPED.uartParity = MODE_00_8N1;

configuration.OPTION.subPacketSetting = SPS_240_00;
configuration.OPTION.RSSIAmbientNoise = RSSI_AMBIENT_NOISE_DISABLED;
configuration.OPTION.transmissionPower = POWER_22;

configuration.TRANSMISSION_MODE.enableRSSI = RSSI_ENABLED;
configuration.TRANSMISSION_MODE.fixedTransmission = FT_TRANSPARENT_TRANSMISSION;
configuration.TRANSMISSION_MODE.enableRepeater = REPEATER_DISABLED;
configuration.TRANSMISSION_MODE.enableLBT = LBT_DISABLED;
configuration.TRANSMISSION_MODE.WORTransceiverControl = WOR_RECEIVER;
configuration.TRANSMISSION_MODE.WORPeriod = WOR_2000_011;
e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
c.close();
}

void loop() {
// Send message

ResponseStatus rs = e22ttl.sendMessage("Hello, world?");
// Check if problem with sending
Serial.println(rs.getResponseDescription());
delay(1000);
}

<div></div>
scanner.ino

/* Look for LoRa transmissions - test with sendTester.ino
* scans channels 0 - 80
* receives in transparent mode
* writes received channel id, RSSI, message to stdout
*/

#include "Arduino.h"
#include "LoRa_E22.h"

// ---------- esp32 pins --------------
LoRa_E22 e22ttl(&Serial2, 15, 21, 19); // RX AUX M0 M1

#define ENABLE_RSSI true

Configuration configuration;
ResponseStructContainer c;

int channel = 0x00;

void setup() {
Serial.begin(9600);
delay(500);

// Startup all pins and UART
e22ttl.begin();
c = e22ttl.getConfiguration();
configuration = *(Configuration*) c.data;
Serial.println(c.status.getResponseDescription());

configuration.ADDL = 0x03;
configuration.ADDH = 0x00;
configuration.NETID = 0x00;
// configuration.CHAN = 0x23;
configuration.SPED.uartBaudRate = UART_BPS_9600;
configuration.SPED.airDataRate = AIR_DATA_RATE_010_24;
configuration.SPED.uartParity = MODE_00_8N1;
configuration.OPTION.subPacketSetting = SPS_240_00;
configuration.OPTION.RSSIAmbientNoise = RSSI_AMBIENT_NOISE_DISABLED;
configuration.OPTION.transmissionPower = POWER_22;
configuration.TRANSMISSION_MODE.enableRSSI = RSSI_ENABLED;
configuration.TRANSMISSION_MODE.fixedTransmission = FT_TRANSPARENT_TRANSMISSION;
configuration.TRANSMISSION_MODE.enableRepeater = REPEATER_DISABLED;
configuration.TRANSMISSION_MODE.enableLBT = LBT_DISABLED;
configuration.TRANSMISSION_MODE.WORTransceiverControl = WOR_RECEIVER;
configuration.TRANSMISSION_MODE.WORPeriod = WOR_2000_011;

e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
c.close();
}

void loop() {
channel = channel % 0x25; // scan only 0x22 - 0x24 for testing
if (channel == 0x00) { channel = 0x22; }

c = e22ttl.getConfiguration(); // change to next channel
configuration = *(Configuration*) c.data;
configuration.CHAN = channel;
e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
Serial.print("channel "); Serial.println(channel);
c.close();
delay(1000);

while (!e22ttl.available()>1) { ;} // wait for message
ResponseContainer rc = e22ttl.receiveMessageRSSI(); // read the String message
// If something goes wrong print error
if (rc.status.code!=1) {
Serial.print("1 "); Serial.println(rc.status.getResponseDescription());
}
else if (rc.rssi > 0) {
// Print the data received
Serial.print(channel);
Serial.print("\t");
Serial.print(rc.rssi);
Serial.print("\t");
Serial.print(rc.data);
Serial.print("\n");
}
channel++;
}

15 March 2024 at 08:31 #30080
Renzo Mischianti
Keymaster
Hi Sid,
try to put a bigger delay for every transmission and give our a feedback.
Bye Renzo
16 March 2024 at 22:51 #30084
Sid
Participant
When I commented out the code that sets the frequency in the iteration through the channels …
```
 c = e22ttl.getConfiguration(); // change to next channel
configuration = *(Configuration*) c.data;
configuration.CHAN = channel;
e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
Serial.print("channel "); Serial.println(channel);
c.close(); 
```
the sketch stays on the setup() channel 0x23 and receives the transmission properly. Should I give up on scanning or is there a good way to change the channel on the fly?
17 March 2024 at 10:40 #30102
Renzo Mischianti
Keymaster
Hi Sid,
try to put the procedure in a function to check if something in the context remains dirty.
Use only local variables and not global ones.
Bye Renzo

18 March 2024 at 22:21 #30111

Sid

Participant

Sorry to be a pest and grateful for your help so far, still haven’t been able to change E22 channels on the fly. I replaced the inline channel-changing code with a function as you suggested but that didn’t fix it. The sketch receives data when the channel is fixed but doesn’t when I cycle through the channel, as in the code blow. I re-implemented it with a Pi Pico and get the same behaviour. Have you other suggestions?

/* Look for LoRa transmissions - on Pi Pico, test with sendTester.ino
 * scans channels 0x22 - 0x24 
 * receives in transparent mode
 * writes received channel id, RSSI, message to stdout
 * 
 * E22		  ----- Raspberry Pi Pico
 * M0         ----- 10
 * M1         ----- 11
 * TX         ----- 9 (PullUP)
 * RX         ----- 8 (PullUP)
 * AUX        ----- 2  (PullUP)
*/

#include "Arduino.h"
#include "LoRa_E22.h"
#define ENABLE_RSSI true
#define beeper 25  // led signals LoRa reception

// ---------- Raspberry PI Pico pins --------------
LoRa_E22 e22ttl(&Serial2, 2, 10, 11); //  RX AUX M0 M1
// -------------------------------------

int channel = 0x00;

void setup() {
  Serial.begin(9600);
  delay(500);

  // Startup all pins and UART
  e22ttl.begin();

//  If you have ever change configuration you must restore It
	Configuration configuration;
  ResponseStructContainer c;
	c = e22ttl.getConfiguration();
	configuration = *(Configuration*) c.data;
	Serial.println(c.status.getResponseDescription());
  configuration.ADDL = 0x03;
  configuration.ADDH = 0x00;
  configuration.NETID = 0x00;

  configuration.CHAN = 23;

  configuration.SPED.uartBaudRate = UART_BPS_9600;
  configuration.SPED.airDataRate = AIR_DATA_RATE_010_24;
  configuration.SPED.uartParity = MODE_00_8N1;

  configuration.OPTION.subPacketSetting = SPS_240_00;
  configuration.OPTION.RSSIAmbientNoise = RSSI_AMBIENT_NOISE_DISABLED;
  configuration.OPTION.transmissionPower = POWER_22;

  configuration.TRANSMISSION_MODE.enableRSSI = RSSI_ENABLED;
  configuration.TRANSMISSION_MODE.fixedTransmission = FT_TRANSPARENT_TRANSMISSION;
  configuration.TRANSMISSION_MODE.enableRepeater = REPEATER_DISABLED;
  configuration.TRANSMISSION_MODE.enableLBT = LBT_DISABLED;
  configuration.TRANSMISSION_MODE.WORTransceiverControl = WOR_RECEIVER;
  configuration.TRANSMISSION_MODE.WORPeriod = WOR_2000_011;
	e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
  c.close();
}

void loop() {  
  channel = channel % 0x25;
  if (channel == 0x00) { channel = 0x22; }   // cycle through only 0x22 - 0x24
  set_channel(channel);                      // receives ok if this line commented out
  Serial.print("channel "); Serial.println(channel);
  delay(2000);

  if (e22ttl.available()>1) {
	  // read the String message
	  ResponseContainer rc = e22ttl.receiveMessageRSSI();
	// Is something goes wrong print error
	  if (rc.status.code!=1) {
	  	Serial.print("0 "); Serial.println(rc.status.getResponseDescription());
  	}
    else if (rc.rssi > 0) {
// Print the data received
  //  Serial.println(rc.status.getResponseDescription());
      Serial.print(channel);
      Serial.print("\t");
      Serial.print(rc.rssi);
      Serial.print("\t");
      Serial.print(rc.data);
      Serial.print("\n");
    }
  }
  channel++;
}
void set_channel(int chan) {
  Configuration configuration;
  ResponseStructContainer c;
  c = e22ttl.getConfiguration();    // change radio to arg channel
  configuration = *(Configuration*) c.data; 
  configuration.CHAN = chan;
  e22ttl.setConfiguration(configuration, WRITE_CFG_PWR_DWN_SAVE);
  c.close();
}

8 April 2024 at 22:34 #30297
Sid
Participant
I’m able to scan channels now. Instead of only changing the channel and saving that parameter alone with setConfiguration() in loop() as in the code above, I copied all of the setup() code between e22ttl.begin() and c.close() into the function set_channel() and call it in loop(), iterating through the channels successfully. When I removed all of the parameter assignments except CHAN from the function, it still worked. Now I see that the above code would have worked if I’d included e22ttl.begin() in the function.
8 April 2024 at 22:36 #30298
Renzo Mischianti
Keymaster
Hi Sid,
thanks for your feedback, if you can share your code, I think can be usefully for a lot of people.
Bye Renzo