Portable RFM69 Signal Scanner

[gohan]

Just wanted to share my tonight creation

It shows Send and Receive RSSI and vcc (that btw is measured via voltage divider and is spot on with my multimeter)

[NeverDie]

Nice job! Looks very dapper.

Alternatively, you may (?) be able to plug your screen directly into the I2C connector used for the TH sensor on:
https://www.openhardware.io/view/268/Arduino-Pro-Mini-Shield-for-RFM69HW
Depends on the pinout, of course.

[gohan]

I thought about it but Vin and GND are swapped

[ooznerol]

Hi great work. Could you give us more details please?

Which version of mysensors do you use ? RF power report seems only availble in dev branch isn't it?

Thanks

[gohan]

Yes, I'm using latest version in dev branch. I also figured I can show both power level and power percentage ( I removed the "VCC" from lcd as it is not really necessary )

[gohan]

Here is the new code that uses the TX power readings. I think that RSSI values and tx power values could be useful to be reported by nodes every once and a while, at least to provide a feedback on how they are doing.

#include <U8glib.h>
#include <Wire.h>

//#define MY_DEBUG  // Enable debug prints

U8GLIB_SSD1306_128X64 lcd(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST);	// Fast I2C / TWI 

#define MY_RADIO_RFM69
#define MY_RFM69_FREQUENCY RFM69_433MHZ
#define MY_RFM69_NEW_DRIVER
#define MY_TRANSPORT_WAIT_READY_MS 10000
//#define MY_NODE_ID 240
//#define VBAT_VCC 

#include <SPI.h>
#include <MySensors.h>  


#define CHILD_ID_VBAT 201						 // Battery voltage

	unsigned long SLEEP_TIME = 2000; // Sleep time between reads (in milliseconds)

#define SKETCH_NAME "Signal Monitor"                // Change to a fancy name you like
#define SKETCH_VERSION "1.0"                    // Your version

MyMessage msgVBat(CHILD_ID_VBAT, V_VOLTAGE);

int Send_rssi, Rec_rssi;                                    // RSSI RFM69 chip
#define CHILD_ID_RSSI_HIGH  7                // RSSI received signal level
#define CHILD_ID_RSSI_LOW   8                // RSSI background noise level
MyMessage msgRSSI1(CHILD_ID_RSSI_HIGH, V_LEVEL);
MyMessage msgRSSI2(CHILD_ID_RSSI_LOW, V_LEVEL);


//=========================
// BATTERY VOLTAGE DIVIDER SETUP
// 1M, 470K divider across battery and using internal ADC ref of 1.1V
// Sense point is bypassed with 0.1 uF cap to reduce noise at that point
// ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
// 3.44/1023 = Volts per bit = 0.003363075
#define VBAT_PER_BITS 0.003363075  
#define VMIN 2.8                                  //  Vmin (radio Min Volt)=1.9V (564v)
#define VMAX 3.44                                 //  Vmax = (2xAA bat)=3.0V (892v)
int batteryPcnt = 0;                              // Calc value for battery %
int batLoop = 0;                                  // Loop to help calc average
int batArray[3];                                  // Array to store value for average calc.
float Vbat;

#ifdef VBAT_VCC
#include <Vcc.h>
const float VccCorrection = 1.0 / 1.0;  // Measured Vcc by multimeter divided by reported Vcc
Vcc vcc(VccCorrection);
#else
int BATTERY_SENSE_PIN = A0;                       // select the input pin for the battery sense point
#endif // VBAT_VCC

void setup()
{
	analogReference(INTERNAL);             // For battery sensing
	lcd.setFont(u8g_font_unifont);
	
}

void presentation()
{
	// Send the Sketch Version Information to the Gateway
	sendSketchInfo(SKETCH_NAME, SKETCH_VERSION);

	// Register all sensors to gw (they will be created as child devices)
	present(CHILD_ID_RSSI_HIGH, S_SOUND);
	present(CHILD_ID_RSSI_LOW, S_SOUND);
	present(CHILD_ID_VBAT, S_MULTIMETER);
}

void loop()
{
	delay(500); // Allow time for radio if power used as reset

	Send_rssi = RFM69_getSendingRSSI();             // read RSSI in RFM69. Measure reception signal from gw
	send(msgRSSI1.set(Send_rssi));                  // send RSSI level
	wait(500);                                 // wait to get idle

	Rec_rssi = RFM69_getReceivingRSSI();           // read RSSI in RFM69. Wait and measure background noise
	send(msgRSSI2.set(Rec_rssi));                  // send RSSI level
	wait(200);                                 // wait for next send

	batM();
	lcd.firstPage();
	do {
		UpdateDisplay();
	} while (lcd.nextPage());
	
	sleep(SLEEP_TIME); //sleep a bit
}

void UpdateDisplay()
{	
	lcd.setPrintPos(0, 20);
	String row;
	row = (String)"S/R: " + Send_rssi + "/"+ Rec_rssi +"db";
	lcd.print(row);
	lcd.setPrintPos(0, 42);
	row = (String)"Pwr%: " + RFM69_getTxPowerPercent() + "%";
	lcd.print(row);
	lcd.setPrintPos(0, 64);
	row = (String)"PWR: " + RFM69_getTxPowerLevel() + "db";
	lcd.print(row);
}

void batM() //The battery calculations
{
	delay(500);
	
	int batteryPcnt;

	// Battery monitoring reading
#ifdef VBAT_VCC
	Vbat = vcc.Read_Volts();
	batteryPcnt = vcc.Read_Perc(VMIN, VMAX);
#else 
	int sensorValue = analogRead(BATTERY_SENSE_PIN);
	Vbat = sensorValue * VBAT_PER_BITS;
	// Calculate the battery in %
	batteryPcnt = static_cast<int>(((Vbat - VMIN) / (VMAX - VMIN))*100.);
#endif 

	delay(500);
	send(msgVBat.set(Vbat, 2));
	Serial.print("Battery percent: "); Serial.print(batteryPcnt); Serial.println(" %");

	// Add it to array so we get an average of 3 (3x20min)
	batArray[batLoop] = batteryPcnt;

	if (batLoop > 2) {
		batteryPcnt = (batArray[0] + batArray[1] + batArray[2] + batArray[3]);
		batteryPcnt = batteryPcnt / 3;

		if (batteryPcnt > 100) {
			batteryPcnt = 100;
		}

		Serial.print("Battery Average (Send): "); Serial.print(batteryPcnt); Serial.println(" %");
		sendBatteryLevel(batteryPcnt);
		batLoop = 0;
	}
	else
	{
		batLoop++;
	}
}

[Grubstake]

Nice clean signal scanner build! I must have one.

Is that an open source proto board you used? I couldn't find it poking around a bit.

Thanks for sharing it!

[mfalkvidd]

@grubstake I think it is an earlier revision of https://www.openhardware.io/view/389/EasyNewbie-PCB-RFM69-HWW-edition-for-MySensors

[Grubstake]

@mfalkvidd
Thanks, it looks like the Rev 9?, where the older pic you posted looks like a smaller version. I didn't realize the board was rearranged between Rev9 and recent R10.

[gohan]

Yes, that was Rev 9, but the sketch would work with anything you have