RFM69 RSSI value report
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@rmtucker Here's the complete sketch. It's a DHT22 temp/humidity battery powered sensor node with an RFM69 radio.
/** * The MySensors Arduino library handles the wireless radio link and protocol * between your home built sensors/actuators and HA controller of choice. * The sensors forms a self healing radio network with optional repeaters. Each * repeater and gateway builds a routing tables in EEPROM which keeps track of the * network topology allowing messages to be routed to nodes. * * Created by Henrik Ekblad <henrik.ekblad@mysensors.org> * Copyright (C) 2013-2015 Sensnology AB * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors * * Documentation: http://www.mysensors.org * Support Forum: http://forum.mysensors.org * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * ******************************* * * REVISION HISTORY * Version 1.0 - Henrik EKblad * * DESCRIPTION * This sketch provides an example how to implement a humidity/temperature * sensor using DHT11/DHT-22 * http://www.mysensors.org/build/humidity */ // Enable debug prints #define MY_DEBUG // Enable and select radio type attached //#define MY_RADIO_NRF24 #define MY_RADIO_RFM69 #define MY_RFM69_FREQUENCY RF69_433MHZ #define MY_NODE_ID 13 // Identity for temp/hum sensor // Set blinking period #define MY_DEFAULT_LED_BLINK_PERIOD 50 // Flash leds on rx/tx/err //#define MY_DEFAULT_ERR_LED_PIN 7 // Error led pin red //#define MY_DEFAULT_RX_LED_PIN 6 // Receive led pin yellow #define MY_DEFAULT_TX_LED_PIN 9 // Transmit led pin green #define MY_WITH_LEDS_BLINKING_INVERSE const byte BATT_ADC = 1; // ADC Pin to measure battery level #include <MySensors.h> #include <DHT.h> unsigned long SLEEP_TIME = 300000; // Sleep time between reads (in milliseconds) #define CHILD_ID_HUM 0 #define CHILD_ID_TEMP 1 #define DHTPIN 18 // Input pin from DHT22 #define DHT22_PWR 6 // Vdc pin DHT22 to get it to sleep #define DHTTYPE DHT22 DHT dht(DHTPIN, DHTTYPE); #define CHILD_ID_RSSI_HIGH 7 // RSSI received signal level #define CHILD_ID_RSSI_LOW 8 // RSSI background noise level #define CHILD_ID_TEMP2 9 // internal temperature RFM69 chip int rssi; // RSSI RFM69 chip int temp2; // Internal temperature RFM69 chip int batteryLevel; // measured battery level int batteryPcnt; // measured battery level in percentage MyMessage msgHum(CHILD_ID_HUM, V_HUM); MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP); MyMessage msgRSSI1(CHILD_ID_RSSI_HIGH, V_VAR1); MyMessage msgRSSI2(CHILD_ID_RSSI_LOW, V_VAR1); MyMessage msgTemp2(CHILD_ID_TEMP2, V_TEMP); void setup() { pinMode(DHT22_PWR,OUTPUT); digitalWrite(DHT22_PWR,HIGH); // power-on dht22 wait(2000); dht.begin(); // Start-up DHT22 sensor Temperature/Humidity } void presentation() { // Send the sketch version information to the gateway and Controller sendSketchInfo("Temp_Hum", "1.0"); // Register all sensors to gw (they will be created as child devices) present(CHILD_ID_HUM, S_HUM); present(CHILD_ID_TEMP, S_TEMP); present(CHILD_ID_RSSI_HIGH, S_CUSTOM); present(CHILD_ID_RSSI_LOW, S_CUSTOM); present(CHILD_ID_TEMP2, S_TEMP); } void loop() { float humidity = dht.readHumidity(); // get dht22 humidity if (isnan(humidity)) { Serial.println("Failed reading humidity from DHT"); } else { send(msgHum.set(humidity, 1)); // send dht22 humidity wait(200); } float temperature = dht.readTemperature(); // get dht22 temperature if (isnan(temperature)) { Serial.println("Failed reading temperature from DHT"); } else { send(msgTemp.set(temperature, 1)); // send dht22 temperature } digitalWrite(DHT22_PWR,LOW); // save some power rssi = _radio.readRSSI(); // read RSSI in RFM69. Measure reception signal from gw send(msgRSSI1.set(rssi)); // send RSSI level wait(500); // wait to get idle rssi = _radio.readRSSI(); // read RSSI in RFM69. Wait and measure background noise send(msgRSSI2.set(rssi)); // send RSSI level wait(200); // wait for next send temp2 = _radio.readTemperature(1); // read temperature in RFM69 send(msgTemp2.set(temp2)); // send temperature batteryLevel = analogRead(BATT_ADC); // (* 0.0032225806) batteryPcnt = batteryLevel / 10; // battery percentage sendBatteryLevel(batteryPcnt); // send battery level in percentage to controller // if (oldBatteryPcnt != batteryPcnt) { // use if not to send every cycle // sendBatteryLevel(batteryPcnt); // oldBatteryPcnt = batteryPcnt; // } sleep(SLEEP_TIME); // sleep a bit digitalWrite(DHT22_PWR,HIGH); // wake up DHT sensor wait(2000); // warm up DHT sensor } void receive(const MyMessage &message) { // We only expect one type of message from controller. But we better check anyway. Serial.println("something came in"); if (message.type==V_VAR1) { // reception to change SLEEP_TIME. SLEEP_TIME = message.getULong(); // send topic: eg. my_RFM69_gw1-in/3/1/1/0/24 30000 (payload in ms) } // MQTT_publish_topic_prefix/Node_Id/Sensor_Id/Cmd_Type/Ack_flag/type(V_VAR1=24) payload }readRSSI(); is an internal function in the RFM69.h / RFM69.cpp library that I'm calling in the sketch to get the RSSI and background noise level.
@jpaulin I can see the value of obtaining Gateway RSSI for individual battery powered nodes to inform programmed power settings on them in the absence of ATC implementation at the Node itself, but not sure I understand the purpose of RSSI readings at the node other than to establish noise thresholds on the Gateway signal.
Although the function of the Gateway is to forward messages to the Controller, is it possible for the Gateway to read and forward RSSI readings for nodes as if locally attached sensors?
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Reading rssi and power on the node it gives you an idea of how much signal that node is getting and if there are interferences around it
@gohan Yes, I understood that aspect. I can imagine certain environments where the SNR might inform change of Node location or shielding or directivity of antenna, or increased output from the Gateway, but I would have thought that a one-off task unless the node noise background changes frequently...
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@gohan True, but if no change to the environment is anticipated, why use battery power to convey it at all?
My own interest in what RSSI the Gateway is receiving should also be a one-time exercise, but is more difficult to implement I suppose.Until such time the 2.2 version is released, and what it provides becomes clearer, I might just do the checking with two portable nodes...
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I can show you how background noise rssi and power output changes during the day and I'm not moving things around
@gohan Not disputing SNRs vary, what I meant by change to the environment at the node was unforeseen pollution influences, such as somebody working with a welder right beside the node after you had already established the peak diurnal noise and set everything up.
The Gateway usually can run permanently at high gain, the Node can only do so at the expense of battery life...
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ACS helps a lot, but by recording rssi and tx power I noticed why thenode occasionally was going offline
@gohan Fair comment, it was the best tool to resolve the problem.
I spent 3 days reviewing what I had programmed, inspected wiring, and testing all DS18B20s, two of which are in the loft, only to discover that a faulty telephone socket had partially dislodged it's pins, my tool to resolve? A magnifying glass.... Isn't technology wonderful...:snail:
