Bat detector
- Thread starter DD4WH
- Start date
I am used to buttons instead of a microscopeIn single ended output the -out pad is floating.
I do have to mention the codec gain used is quite high,
This is what I see with codec gain on 10
I also made a few noises....
The spectrum of the silent part looks like this.
When I have codec gain set to 20 I see this
Sorry for the different scales....
Somehow the peak near 23Khz seems a lot larger than the rest of the noise.....
I do have to mention the codec gain used is quite high,
This is what I see with codec gain on 10
I also made a few noises....
The spectrum of the silent part looks like this.
When I have codec gain set to 20 I see this
Sorry for the different scales....
Somehow the peak near 23Khz seems a lot larger than the rest of the noise.....
Frank,
Maybe you could use a SD-card extender like this to be able to seperate the SD powersupply from the Teensy. On the teensy it is very hard to do that but here you can easily cut a track.
There are also versions with white plastic ribbon cable but I think those could be a bit more difficult to solder on to.
Edwin
Maybe you could use a SD-card extender like this to be able to seperate the SD powersupply from the Teensy. On the teensy it is very hard to do that but here you can easily cut a track.
There are also versions with white plastic ribbon cable but I think those could be a bit more difficult to solder on to.
Edwin
DD4WH
Well-known member
Hi Edwin,
thanks a lot! I will think more about that!
However, adding additional hardware for features already implemented (built-in SD card) is a bit annyoing, and I think I read that the built-in SD card is much faster, which could be important for high speed ultrasound logging.
All the best,
Frank
thanks a lot! I will think more about that!
However, adding additional hardware for features already implemented (built-in SD card) is a bit annyoing, and I think I read that the built-in SD card is much faster, which could be important for high speed ultrasound logging.
All the best,
Frank
The externder was just an idea to be able to cut a power supply track and put a separate 3v3 source on the SD card to try and get the writing noise out of the teensy.
I did some experiments again with the SGTL gain settings microphones and amplifiers. We already knew that using high gains settings on the SGTL adds a lot of noise.
Both the ICS and SPU microphines seem to have some noise around 23Khz, with the SPU it is presented as a wider lower hump but the ICS presents a larger spike.
The amplifiers help to suppress the low frequency sounds and enhance the high frequency sounds.
Using these, or connecting the microphones directly seem to show the same raised levels on or around 23Khz.
Although it seemed the noise is coming form the microphone the SGTL5000 also seems to have a big part in it.
Of course this is not a huge problem but I just wanted to get rid of the vertical bar on the waterfall screen when I am searching for bats on high gain.
Once one has located bats and they are closer one can reduce the gain and the bar becomes barely noticeable.
The main problem is introduced by the user I guess, when there is no bat around, one tends to turn up the gain in the hope and hear some bats.
If one wants great signal to noise level I guess the SGTL is not the best thing to use.
Your stationary bat recorder is probably a lot better at recording but for running around the field using the detection modes and de graphical presentation dit approach is just great.
Edwin
I did some experiments again with the SGTL gain settings microphones and amplifiers. We already knew that using high gains settings on the SGTL adds a lot of noise.
Both the ICS and SPU microphines seem to have some noise around 23Khz, with the SPU it is presented as a wider lower hump but the ICS presents a larger spike.
The amplifiers help to suppress the low frequency sounds and enhance the high frequency sounds.
Using these, or connecting the microphones directly seem to show the same raised levels on or around 23Khz.
Although it seemed the noise is coming form the microphone the SGTL5000 also seems to have a big part in it.
Of course this is not a huge problem but I just wanted to get rid of the vertical bar on the waterfall screen when I am searching for bats on high gain.
Once one has located bats and they are closer one can reduce the gain and the bar becomes barely noticeable.
The main problem is introduced by the user I guess, when there is no bat around, one tends to turn up the gain in the hope and hear some bats.
If one wants great signal to noise level I guess the SGTL is not the best thing to use.
Your stationary bat recorder is probably a lot better at recording but for running around the field using the detection modes and de graphical presentation dit approach is just great.
Edwin
I just updated some documentation.
I don't quite remember if I shared the link to these files before but any eBay buyer of the V0.2 board als got the link form the item description.
The link now holds the new files.
Anyway, if you still have to start working on the V0.2 board here are the updated files.
The most important changes:
Display update noise is reduced by quite a bit. (100 ohm resistors in all data lines)
Added instructions on how to build a transistor amp on this board if you like that better.
Beside that there was some minor parts optimization.
The V0.2 version was designed to use a low noise rail-to-rail opamp that would give us a bigger dynamic range and less noise.
Unfortunately the opamp als picked up some display update noise. This noise is nearly gone by using the resistors in the datalines the opamp version now is just slightly better than te transistor version. No huge differences so if you have the transistor board version keep it. The biggest improvement is in reducing the data noise, of course one can also use the resistors in the data lines with the transistor version.
If one wants to use standard headers, it is better to use a transistor amplifier.
Kind regards,
Edwin
Almost forgot, there is some extra information on LCD revisions, some versions use direct LED drive, others have a transistor on the LED pin. One can determine the difference if there is a Q1 part next to the U1. It makes a huge difference in the resistor used on the LED pin.
I don't quite remember if I shared the link to these files before but any eBay buyer of the V0.2 board als got the link form the item description.
The link now holds the new files.
Anyway, if you still have to start working on the V0.2 board here are the updated files.
The most important changes:
Display update noise is reduced by quite a bit. (100 ohm resistors in all data lines)
Added instructions on how to build a transistor amp on this board if you like that better.
Beside that there was some minor parts optimization.
The V0.2 version was designed to use a low noise rail-to-rail opamp that would give us a bigger dynamic range and less noise.
Unfortunately the opamp als picked up some display update noise. This noise is nearly gone by using the resistors in the datalines the opamp version now is just slightly better than te transistor version. No huge differences so if you have the transistor board version keep it. The biggest improvement is in reducing the data noise, of course one can also use the resistors in the data lines with the transistor version.
If one wants to use standard headers, it is better to use a transistor amplifier.
Kind regards,
Edwin
Almost forgot, there is some extra information on LCD revisions, some versions use direct LED drive, others have a transistor on the LED pin. One can determine the difference if there is a Q1 part next to the U1. It makes a huge difference in the resistor used on the LED pin.
Edwin
Have you tried to use the tl972 with a higher gain and using the SGTL at a lower gain?
Alain
Yes I did, somehow it seems I did not post my reply yesterday.
I set the amplification close to 40dB on the TL972, these are the results i got in a quit room with SGTL gain set to 0
I also did the same with SGTL gain set to 10
With the ICS microphone I still get that peek although it is very low when using 0dB on the SGTL the SPU microphone also gives me a bit of signal near this frequency but it is much wider and a lot lower.
I would still like to gave some control over the gain, If i do set the gain on the opamp very high I have only little control over the total gain.
An extra control could be an option but I do not really want an extra switch or pot.
Other experiments showed the amplification in the SGTL adds quite a bit of noise when it is at a high level. This 23Khz signal also proves we should better have more old fashioned analog amplification.
For that reason I already changed the resistors a bit in the last builds.
Since the SPU microphone has a wider and lower hump than the ICS, I still choose that in combination with this bat detector. Maybe I do not have the lowest noise level microphone but I think with the rest of the hardware one will hardly notice the difference.
Kind regards,
Edwin
seriesman71
Member
Query regarding resistors in documents for build 0.2a
Hi Edwin
Can you clarify where the 100 ohm resistor bodies go between teensy and audio board please. Do the main resistor bodies go between the teensy and the audio board or under the audio board and the main pcb with just a wire link between the teensy and the audio board. Photo is not too clear. Many thanks.
Hi Edwin
Can you clarify where the 100 ohm resistor bodies go between teensy and audio board please. Do the main resistor bodies go between the teensy and the audio board or under the audio board and the main pcb with just a wire link between the teensy and the audio board. Photo is not too clear. Many thanks.
The resistors are all soldered on the teensy so these are between the teensy and audioboard.
I hope this helps.
On the last boards I soldered I cut the pins like this so that mounting was easier.
Yes I know, the second picture are not 100 ohm resistors, I ran out of 100 ohm and used 150 which also work.
Edwin
seriesman71
Member
THanks Edwin, yes that helps.
Regards
Barry
Regards
Barry
CorBee
Well-known member
next software update: requests ??
Hi,
Behind the screens I am working on a rather large change/update of the current sourcecode. If anybody has specific wishes/ideas/bugs I would like to hear them to consider adding them to the sourcecode. For me this is more or less the last week that I can spend more than average time on this project. From next week on my daytime job will be more demanding than in the past weeks and that means the progress will slow down.
regards
Cor
Hi,
Behind the screens I am working on a rather large change/update of the current sourcecode. If anybody has specific wishes/ideas/bugs I would like to hear them to consider adding them to the sourcecode. For me this is more or less the last week that I can spend more than average time on this project. From next week on my daytime job will be more demanding than in the past weeks and that means the progress will slow down.
regards
Cor
seriesman71
Member
Hi
Is it possible include an option to reverse the direction of the encoders? I have two teensybats with encoders that work in opposite directions - very confusing. I know you posted v0.90 in two versions with opposite direction encoders but later hex files have all been one direction only. It would save having to have two hex versions of the same release. Thanks
seriesman71
Member
Tried out the latest version
Hi. Downloaded the second version of 095 as tried by Edwin. Its working well on my transistor amplifier model. The revised menu layout is a big improvement, gets a lot of material irelevant to using the device in the field out of the way. Its simpler to use by far. Thanks for all your hard work, its obviously taken a great deal of effort.
Hi. Downloaded the second version of 095 as tried by Edwin. Its working well on my transistor amplifier model. The revised menu layout is a big improvement, gets a lot of material irelevant to using the device in the field out of the way. Its simpler to use by far. Thanks for all your hard work, its obviously taken a great deal of effort.
CorBee
Well-known member
v096 major update
Hi,
I have just uploaded both the source and the compiled hex for V096. As mentioned before this contains a large amount of changes. Edwin (pe1pwf) and Seriesman71 have been testing this also and I hope this works for everybody as planned.
The biggest change is the way the menu now works, with more and more settings entering the main menu it started to become a cluttered system. Now most settings have been moved to a separate settings page and the main menu only contains necessary options to control/use the detector.
Have fun,
Cor
* v0.95 MAJOR CHANGES !!!
- compacted the main menu to have all less often changed settings in a separate SETTINGS page
- setting of both time and date can be done from the new settings page
- updated startup from EEprom stored settings (more settings stored (see settings page))
- improved spectrum-graph functionality (peak-hold now visibible, was present for many versions but invisible)
- made as many as possible user-changeable options cyclic (if the user tries to rotate the encoder above the highest value automatically go to the lowest value)
- time was updating still on screen every minute during recording, now has been removed
- added a routine to monitor VIN (or anything else) voltage on A3 (pin17)
- read unique SN (allows identifying different detectors, one for testing with additional functions)
Hi,
I have just uploaded both the source and the compiled hex for V096. As mentioned before this contains a large amount of changes. Edwin (pe1pwf) and Seriesman71 have been testing this also and I hope this works for everybody as planned.
The biggest change is the way the menu now works, with more and more settings entering the main menu it started to become a cluttered system. Now most settings have been moved to a separate settings page and the main menu only contains necessary options to control/use the detector.
Have fun,
Cor
* v0.95 MAJOR CHANGES !!!
- compacted the main menu to have all less often changed settings in a separate SETTINGS page
- setting of both time and date can be done from the new settings page
- updated startup from EEprom stored settings (more settings stored (see settings page))
- improved spectrum-graph functionality (peak-hold now visibible, was present for many versions but invisible)
- made as many as possible user-changeable options cyclic (if the user tries to rotate the encoder above the highest value automatically go to the lowest value)
- time was updating still on screen every minute during recording, now has been removed
- added a routine to monitor VIN (or anything else) voltage on A3 (pin17)
- read unique SN (allows identifying different detectors, one for testing with additional functions)
I have used Teensy Bat Detector a couple of times and heard some bats.
To night I was out again and I did not hear any bats but my friend with a Pettersson D200 did.
How is the sensitivity of Teensy Bat Detector compared with example D200?
I am using microphone ICS-40730, do I need to do any changes on the mic amplifier then using ICS-40730?
Regards Bengt
To night I was out again and I did not hear any bats but my friend with a Pettersson D200 did.
How is the sensitivity of Teensy Bat Detector compared with example D200?
I am using microphone ICS-40730, do I need to do any changes on the mic amplifier then using ICS-40730?
Regards Bengt
CorBee
Well-known member
Hi,
Comparing detectors is not a very simple thing unless it is done in a controlled environment. Can you tell which pre-amplifier you used ? How is your microphone constructed ?
Frank (DD4WH) has posted some tests of microphones on this forum earlier (I dont have the exact message# at hand), it was showing that these microphones do work well.
regards
Cor
Comparing detectors is not a very simple thing unless it is done in a controlled environment. Can you tell which pre-amplifier you used ? How is your microphone constructed ?
Frank (DD4WH) has posted some tests of microphones on this forum earlier (I dont have the exact message# at hand), it was showing that these microphones do work well.
regards
Cor
CorBee
Well-known member
Hi,
I have just uploaded a proper working hex and also updated the sourcecode. In the lib subdirectory I have added the most recent setup of the libraries I am using for those that are compiling the sourcecode themselves.
This version can be recognized at startup as v0.96 20190824.
regards
Cor
Sensitivity
It is with one transistor, ICS-40730 mounted at the connector on the PCB front and a 3 mm hole in the enclosure.
I shall do some measurement on the mic amplifier, which amplitud can I expect when I do some noise with a key ring?
And maybe test without the enclosure.
Regards Bengt
It is with one transistor, ICS-40730 mounted at the connector on the PCB front and a 3 mm hole in the enclosure.
I shall do some measurement on the mic amplifier, which amplitud can I expect when I do some noise with a key ring?
And maybe test without the enclosure.
Regards Bengt
CorBee
Well-known member
Hi,
The amplitude will be depending on the distance from the key-ring to your detector, the loudness of your ring (intensity), the gain for the one-transistor amplifier (which design ?) and the mic_gain setting of the teensy_batdetector .
One thing you can try to get a bit better understanding of the sensitivity is listening to for instance a constant high frequent signal coming from many devices with clocks inside. I have for instance an audio-player that emits this signal and I can pick it up about a meter away or so ... depending on the gain I use. Or a programmable timer (to switch appliances) will also. When you have a good and reliable source you can start recording/testing your device settings against that.
Cor
EDIT: this is my current 1-transistor amplifier (BC547=BC550c)
