Microwave Radar Module as PIR replacement.
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All things from my previous post regarding the wiring are still needed:
Here is a stripped down example on how to use the FC1816 Microwave Sensor. You need the following library:
https://github.com/RobTillaart/Arduino/tree/master/libraries/Statistic
#include "Statistic.h" #define MICRO_SENSOR_ANALOG_PIN A1 void setup() { Serial.begin(57600); Serial.print("begin"); // Microwave pinMode(5,OUTPUT); // VCC BISS0001 digitalWrite(5,HIGH); pinMode(6,OUTPUT); // Enabled digitalWrite(6,LOW); // DISABLE PLEASE! pinMode(7,OUTPUT); // GND digitalWrite(7,LOW); pinMode(A1,INPUT); // PIR 2nd amplification stage pinMode(A0,OUTPUT); // UPD microwave generator digitalWrite(A0,HIGH); } void loop() { // Report Microwave static Statistic mw_s; static uint16_t stdev_sum = 0; //mw_s.clear(); //digitalWrite(8,HIGH); //delay(100); analogRead(MICRO_SENSOR_ANALOG_PIN); uint16_t reading; for(int i = 0; i < 200; i++) { reading = analogRead(MICRO_SENSOR_ANALOG_PIN); mw_s.add(reading); //Serial.println(reading); //Serial.flush(); //delay(50); //LowPower.powerDown(SLEEP_60MS, ADC_ON, BOD_OFF); //delay(1); } Serial.print(mw_s.minimum()); Serial.print(","); Serial.print(mw_s.average()); Serial.print(","); Serial.print(mw_s.maximum()); Serial.print(","); Serial.print(mw_s.pop_stdev()); Serial.print(","); stdev_sum += mw_s.pop_stdev(); Serial.print(stdev_sum); //Serial.print(","); Serial.println(); stdev_sum *= 0.9; mw_s.clear(); }I just had the idea to sum up the std-dev and decrease it by 10% every round. Thus the code is less prone to peaks.
stdev_sum is the lower dark blue line which can now be much easier compared to a threshold.
Some measurement with my µCurrent-Gold:
Unmodified code as above, power LED removed from ProMini @ 8Mhz internal osci with LDO desoldered
4,8mAI tried to put the FC1816 into sleep by disable the power to the Microwave generator but this doesn't work.
I modified the fuses for 8Mhz with 0ms wakeup delay for stabelizing the oscillator. No risk no phun ;-)The most practical solution I got to replace a PIR (still nothing as close as a PIR ;-ö)
1530µA
with this code:
Note that the radar generator just can't be disable as it needs 10-15seconds to stabelize after power up
#include <LowPower.h> #include "Statistic.h" #define MICRO_SENSOR_ANALOG_PIN A1 void setup() { Serial.begin(57600); Serial.print("begin"); // Microwave pinMode(5,OUTPUT); // VCC BISS0001 digitalWrite(5,HIGH); pinMode(6,OUTPUT); // Enabled digitalWrite(6,LOW); // DISABLE PLEASE! pinMode(7,OUTPUT); // GND digitalWrite(7,LOW); pinMode(A1,INPUT); // PIR 2nd amplification stage pinMode(A0,OUTPUT); // UPD microwave generator digitalWrite(A0,HIGH); } void loop() { // Report Microwave static Statistic mw_s; static uint16_t stdev_sum = 0; //mw_s.clear(); //delay(100); analogRead(MICRO_SENSOR_ANALOG_PIN); uint16_t reading; for(int i = 0; i < 10; i++) { LowPower.powerDown(SLEEP_15Ms, ADC_ON, BOD_OFF); reading = analogRead(MICRO_SENSOR_ANALOG_PIN); mw_s.add(reading); //Serial.println(reading); //Serial.flush(); //delay(50); LowPower.powerDown(SLEEP_15Ms, ADC_ON, BOD_OFF); //delay(1); } Serial.print(mw_s.minimum()); Serial.print(","); Serial.print(mw_s.average()); Serial.print(","); Serial.print(mw_s.maximum()); Serial.print(","); Serial.print(mw_s.pop_stdev()); Serial.print(","); stdev_sum += mw_s.pop_stdev(); Serial.print(stdev_sum); //Serial.print(","); Serial.println(); Serial.flush(); stdev_sum *= 0.9; mw_s.clear(); } -
After a few more days of testing I noticed these ugly "PEAKS" from my FC1816 readings. I added lots of capacitors and RC and LC sections but still .. nasty little peaks (left side in the beginning)
In my previous post replace this line:
stdev_sum += mw_s.pop_stdev();with this:
// Ignore the first 3 peaks within short succession // Real movement should mean there are more peaks/activity over a long time static uint8_t peakcount = 0; if(mw_s.pop_stdev() > 30 && peakcount < 3) { peakcount++; } else { stdev_sum += mw_s.pop_stdev(); stdev_sum *= 0.92; // if (stdev_sum >= 7) stdev_sum -= 7; // Default background noise if (stdev_sum > 512) stdev_sum = 512; if(peakcount > 0) peakcount--; }With this code the first 3 peaks are essentially removed .. if there is really some movement it should last for a few seconds and would still be detected.
I have invested like 10-20hours into testing and debugging the FC1816 and I can say .. this thing is .. peculiar ..
I hate it cause of the spikes, the amplification which has to be manually altered with a pot .. but at the same time I love it ..
I can detect my foot beckoning 2-3meters apart in my bed :D
An example of the code snipped in action:
Here you can see the big spikes in the beginning completely ignored (1)
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After a few more days of testing I noticed these ugly "PEAKS" from my FC1816 readings. I added lots of capacitors and RC and LC sections but still .. nasty little peaks (left side in the beginning)
In my previous post replace this line:
stdev_sum += mw_s.pop_stdev();with this:
// Ignore the first 3 peaks within short succession // Real movement should mean there are more peaks/activity over a long time static uint8_t peakcount = 0; if(mw_s.pop_stdev() > 30 && peakcount < 3) { peakcount++; } else { stdev_sum += mw_s.pop_stdev(); stdev_sum *= 0.92; // if (stdev_sum >= 7) stdev_sum -= 7; // Default background noise if (stdev_sum > 512) stdev_sum = 512; if(peakcount > 0) peakcount--; }With this code the first 3 peaks are essentially removed .. if there is really some movement it should last for a few seconds and would still be detected.
I have invested like 10-20hours into testing and debugging the FC1816 and I can say .. this thing is .. peculiar ..
I hate it cause of the spikes, the amplification which has to be manually altered with a pot .. but at the same time I love it ..
I can detect my foot beckoning 2-3meters apart in my bed :D
An example of the code snipped in action:
Here you can see the big spikes in the beginning completely ignored (1)
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Currently I don't plan to make a library .. a library implies that the sensor is very easy to use .. plug in + import library.
The FC1816 is not such a sensor.
- Needs Voltage-Supply filter (RC Section)
- Need separate cable to grab the signal at the 2nd amplification stage
- Need potentiometer to lower the amplification
- Is very prone to random noise (in fact even entering RF24 or ATMEGA328 low power mode might increase noise floor a lot)
Using a "simple to use" library and not getting the expected result of an "easy"-sensor would be very disappointing. For now I would say this is an advanced sensor with some pitfalls.
I update this thread with my findings to hopefully make everybodys life a bit easyer if you want to tinker with the FC1816 although you now know it is a little beast ;-)
If you need any help just ask here and I will support you the best I can.
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It's a review of some radar sensors if anyone is interested.
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Does anyone have a complete MySensors sketch for these that they would be willing to share?
I tried to create a wildlife sensor with it a while ago.. but the signal seemed to always be high.
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Does anyone have a complete MySensors sketch for these that they would be willing to share?
I tried to create a wildlife sensor with it a while ago.. but the signal seemed to always be high.
I when the tested here is such:
They work great on an almost standard PIR MOTION sketch
..By the way why no one makes these motion sensors MW for MySensors on openhardware, it seems there is nothing complicated?
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Does anyone have a complete MySensors sketch for these that they would be willing to share?
I tried to create a wildlife sensor with it a while ago.. but the signal seemed to always be high.
@alowhum
Now I remembered that I once shot a video about this sensor. In the description below the video there are links to sketches that work with such sensors. But for this video I did not do subtitles in English, in sketches comments also seem to be in Russian. But I think it won't be a problem.
