Most reliable "best" radio
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Curiously, this keyfinder does appear to function fairly decently all the way down to 1.9v:
and its current draw actually drops to 29ua:
I'm including this screenshot of the Rx interval for completeness:
By the time it reaches 1.8v, it dies rapidly because it spends most of the 1 second duty cycle listening:
What the PPK2 doesn't do is simulate the voltage droop that a CR2032 can experience. Not at all sure what happens under those conditions, but maybe (probably?) it contributes to the seemingly short battery life. If that's the case, maybe these keyfinder receivers could be rehabilitated to last longer before needing a battery replacement.
By the way, when I checked the voltage remaining on the coincell taken from this keyfinder receive, it measures about 3mv. So, it got drained practically all the way to zero.
Anyhow, according to energizer, their CR2032 has 235mah of capacity when measured from fresh down to 2.0v (https://data.energizer.com/pdfs/cr2032.pdf). So, doing the math on that, assuming a 35ua burn rate, it should theoretically last 279 days, or about 9 months. That would be the lower bound. If one assumes 29ua as the burn rate, then it could last 11 months. That would be the upper bound. i.e. theoretically, it might last somewhere from 9-11 months. Definitely not two years. Also, I'm definitely got getting anything in that range on my keyfinder receiver tags--they die much sooner than that. I'm guessing it's CR2032 voltage droop that gets worse as the battery gets depleted which leads to premature failure. I wondering whether simply soldering in a suitably large value ceramic capacitor between VCC and GND might help it power through the droop and live up to its design potential? Better yet, I'd be willing to trade off responsiveness for much better battery life. Rather than checking once per second, maybe it could be modified to listen much less often than that.
@NeverDie said in Most reliable "best" radio:
By the way, when I checked the voltage remaining on the coincell taken from this keyfinder receive, it measures about 3mv. So, it got drained practically all the way to zero.
I've seen this when playing with 328's and 8266's. When voltages drop to the min threshold, the devices fail into a funky state drawing big current. For that reason, my current designs give out a yelp at a moderately low voltage, if there is a radio attached. Then go into deep sleep hoping that a rescue arrives. Deep discharges are really problematic for rechargeable liOn batteries. The advice is to abandon the battery because of potential changes to chemistry and the risk of fire on recharge.
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@NeverDie said in Most reliable "best" radio:
By the way, when I checked the voltage remaining on the coincell taken from this keyfinder receive, it measures about 3mv. So, it got drained practically all the way to zero.
I've seen this when playing with 328's and 8266's. When voltages drop to the min threshold, the devices fail into a funky state drawing big current. For that reason, my current designs give out a yelp at a moderately low voltage, if there is a radio attached. Then go into deep sleep hoping that a rescue arrives. Deep discharges are really problematic for rechargeable liOn batteries. The advice is to abandon the battery because of potential changes to chemistry and the risk of fire on recharge.
@Larson said in Most reliable "best" radio:
@NeverDie said in Most reliable "best" radio:
By the way, when I checked the voltage remaining on the coincell taken from this keyfinder receive, it measures about 3mv. So, it got drained practically all the way to zero.
I've seen this when playing with 328's and 8266's. When voltages drop to the min threshold, the devices fail into a funky state drawing big current. For that reason, my current designs give out a yelp at a moderately low voltage, if there is a radio attached. Then go into deep sleep hoping that a rescue arrives. Deep discharges are really problematic for rechargeable liOn batteries. The advice is to abandon the battery because of potential changes to chemistry and the risk of fire on recharge.
What kind of device/component do you use to make the yelp sound? I've looked for tiny piezo's that could maybe do this, but they all seem to be different degrees of large. I know it should be possible to be tiny, becaue, for example, a digital wristwatch is able to make audible beeps. On the other hand, after looking at some teardowns, I guess digital watches uses piezo disks that are at least 1/2" in diameter. Hmmmm.... Is that really as small as it gets? Anyone here know? What about hearing aids? Surely they have something smaller. The smallest thing I've found so far has been this: https://owolff.com/page140.aspx?recordid140=534&output=pdf&delay=3000&margin=1cm which is 5mm in diameter. So, I guess forget mounting anything directly to the PCB board: wired discs are the way it's done apparently and then just tuck it somewhere inside the project enclosure.
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@Larson said in Most reliable "best" radio:
@NeverDie said in Most reliable "best" radio:
By the way, when I checked the voltage remaining on the coincell taken from this keyfinder receive, it measures about 3mv. So, it got drained practically all the way to zero.
I've seen this when playing with 328's and 8266's. When voltages drop to the min threshold, the devices fail into a funky state drawing big current. For that reason, my current designs give out a yelp at a moderately low voltage, if there is a radio attached. Then go into deep sleep hoping that a rescue arrives. Deep discharges are really problematic for rechargeable liOn batteries. The advice is to abandon the battery because of potential changes to chemistry and the risk of fire on recharge.
What kind of device/component do you use to make the yelp sound? I've looked for tiny piezo's that could maybe do this, but they all seem to be different degrees of large. I know it should be possible to be tiny, becaue, for example, a digital wristwatch is able to make audible beeps. On the other hand, after looking at some teardowns, I guess digital watches uses piezo disks that are at least 1/2" in diameter. Hmmmm.... Is that really as small as it gets? Anyone here know? What about hearing aids? Surely they have something smaller. The smallest thing I've found so far has been this: https://owolff.com/page140.aspx?recordid140=534&output=pdf&delay=3000&margin=1cm which is 5mm in diameter. So, I guess forget mounting anything directly to the PCB board: wired discs are the way it's done apparently and then just tuck it somewhere inside the project enclosure.
@NeverDie said in Most reliable "best" radio:
What kind of device/component do you use to make the yelp sound?
My present "Yelp" design comes from a Thingspeak script that sends an email. Yelp may have been the wrong word, but I was thinking of smoke detectors that beep to say, "I'm dying, replace my battery". Previously, I built a WiFi mouse trap that sent email/text/phonecall via SMTP2GO if the trap was tripped (mouse, or no mouse). That was fun! That code could easily be modified to trigger on a voltage threshold, or any other variable.
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@NeverDie said in Most reliable "best" radio:
What kind of device/component do you use to make the yelp sound?
My present "Yelp" design comes from a Thingspeak script that sends an email. Yelp may have been the wrong word, but I was thinking of smoke detectors that beep to say, "I'm dying, replace my battery". Previously, I built a WiFi mouse trap that sent email/text/phonecall via SMTP2GO if the trap was tripped (mouse, or no mouse). That was fun! That code could easily be modified to trigger on a voltage threshold, or any other variable.
image url)@Larson That's a nice, clean looking, elegant design. If you have any idea on how to kill skunks, let me know. They are destroying my lawn. Live capture doesn't seem practical for skunks, for obvious reasons. I've seen one youtube that demonstrates a deadfall device--and proves it works--but it's the only example I've managed to find. There do exist professional services, but they charge a couple hundred bucks per animal removed, but after removal they can't legally release them (because they are officially pests), so the pro's just end up killing them anyway.
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@Larson That's a nice, clean looking, elegant design. If you have any idea on how to kill skunks, let me know. They are destroying my lawn. Live capture doesn't seem practical for skunks, for obvious reasons. I've seen one youtube that demonstrates a deadfall device--and proves it works--but it's the only example I've managed to find. There do exist professional services, but they charge a couple hundred bucks per animal removed, but after removal they can't legally release them (because they are officially pests), so the pro's just end up killing them anyway.
@NeverDie For skunks, and racoons I use an electric fence. I string a wire around the lawns & ferns about 6" up from grade using non-conducting stakes. I think it works and is non-lethal. The e-fence was the smallest Coastal Farm offers. Our cat has 'figured' it out and knows to stay away.
In the spirit of radio electronics, I did build a system for mole elimination. It was complicated. I use a vibration detector/WiFi (ESPNOW) that sends notice to a piezo beeper inside the house. The detector is planted in the last active mole pile. If I hear the beeper I jump to action to hit a button (Transmit/Recieve pair) to ignite an electronic firecracker that would be burried in the last visited mole pile. I could have automated that button-pushing task, but the extra human control made it safer and more entertaining. The firecracker is be fitted with a nicrome wire fork, inplace of the normal fuse. The firecrackers I prepared were painted in some waterproof paint to keep them from degrading in the moist soil. An 18V Ryobi tool battery is used for the power source in the relay circuit because that gives enough juice to burn the nicrome wire. I tested it but have yet to deploy it. Here is the circuit for the igniter.
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@NeverDie For skunks, and racoons I use an electric fence. I string a wire around the lawns & ferns about 6" up from grade using non-conducting stakes. I think it works and is non-lethal. The e-fence was the smallest Coastal Farm offers. Our cat has 'figured' it out and knows to stay away.
In the spirit of radio electronics, I did build a system for mole elimination. It was complicated. I use a vibration detector/WiFi (ESPNOW) that sends notice to a piezo beeper inside the house. The detector is planted in the last active mole pile. If I hear the beeper I jump to action to hit a button (Transmit/Recieve pair) to ignite an electronic firecracker that would be burried in the last visited mole pile. I could have automated that button-pushing task, but the extra human control made it safer and more entertaining. The firecracker is be fitted with a nicrome wire fork, inplace of the normal fuse. The firecrackers I prepared were painted in some waterproof paint to keep them from degrading in the moist soil. An 18V Ryobi tool battery is used for the power source in the relay circuit because that gives enough juice to burn the nicrome wire. I tested it but have yet to deploy it. Here is the circuit for the igniter.@Larson Will a firecracker actually kill a mole? This guy shows off his simple contraption that uses 500v to instantly kill rodents:
https://www.youtube.com/watch?v=-xkOtVlDUbwThe key seems to be charging high voltage capacitors, so that enough current is released at 500v when triggered. I know: dangerous as hell, but maybe this is where your wireless human-in-the-loop firing trigger could come into play so that it doesn't kill anything that it's not supposed to.
He says it's highly effective.
I don't know whether something like that would work for moles or not. I guess it depends on whether they ever leave their holes to look for food or whether they stay underground all the time.
I wouldn't feel comfortable walking up to something charged to 500v, but maybe that's where radio electronics could completely disarm it down to zero volts when commanded before you even think of touching it. His is more basic and doesn't have that added feature. I would want redundant everything on the safety features so that there's no chance of it going wrong.
As for charging it up, I think one of these would work for fairly cheap:
https://www.amazon.com/gp/product/B07JG4K6S6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
as long as you terminate the charge when it gets to 500v and not let it continue on to 15,000 volts, which would destroy your charge capacitor. Since it comes in a pack of two, maybe the other one could be used to energize an electric fence? I know nothing about electric fences or what voltage they use, but I would hazard a guess that the circuitry is similar (flyback transformer design), and then all you would need is the right kind of wire and some insulated stakes.An electric fence is an interesting idea, provided it doesn't ignite dead leaves and create a fire. Not sure whether or not that's even a risk. I presume that professional electric fences wouldn't do that.
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@NeverDie For skunks, and racoons I use an electric fence. I string a wire around the lawns & ferns about 6" up from grade using non-conducting stakes. I think it works and is non-lethal. The e-fence was the smallest Coastal Farm offers. Our cat has 'figured' it out and knows to stay away.
In the spirit of radio electronics, I did build a system for mole elimination. It was complicated. I use a vibration detector/WiFi (ESPNOW) that sends notice to a piezo beeper inside the house. The detector is planted in the last active mole pile. If I hear the beeper I jump to action to hit a button (Transmit/Recieve pair) to ignite an electronic firecracker that would be burried in the last visited mole pile. I could have automated that button-pushing task, but the extra human control made it safer and more entertaining. The firecracker is be fitted with a nicrome wire fork, inplace of the normal fuse. The firecrackers I prepared were painted in some waterproof paint to keep them from degrading in the moist soil. An 18V Ryobi tool battery is used for the power source in the relay circuit because that gives enough juice to burn the nicrome wire. I tested it but have yet to deploy it. Here is the circuit for the igniter.@Larson Do you have any links to this please? I found next doors 2 new cats killing 2 young birds they had paicked out of the tree and onto my lawn. The owners are un-cooperative on the issue and the cats have been using my garden as their own litter tray..... Garlic, chilli powder and vinegar have had no effect so I need to up the game!
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@Larson Do you have any links to this please? I found next doors 2 new cats killing 2 young birds they had paicked out of the tree and onto my lawn. The owners are un-cooperative on the issue and the cats have been using my garden as their own litter tray..... Garlic, chilli powder and vinegar have had no effect so I need to up the game!
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@Larson Will a firecracker actually kill a mole? This guy shows off his simple contraption that uses 500v to instantly kill rodents:
https://www.youtube.com/watch?v=-xkOtVlDUbwThe key seems to be charging high voltage capacitors, so that enough current is released at 500v when triggered. I know: dangerous as hell, but maybe this is where your wireless human-in-the-loop firing trigger could come into play so that it doesn't kill anything that it's not supposed to.
He says it's highly effective.
I don't know whether something like that would work for moles or not. I guess it depends on whether they ever leave their holes to look for food or whether they stay underground all the time.
I wouldn't feel comfortable walking up to something charged to 500v, but maybe that's where radio electronics could completely disarm it down to zero volts when commanded before you even think of touching it. His is more basic and doesn't have that added feature. I would want redundant everything on the safety features so that there's no chance of it going wrong.
As for charging it up, I think one of these would work for fairly cheap:
https://www.amazon.com/gp/product/B07JG4K6S6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
as long as you terminate the charge when it gets to 500v and not let it continue on to 15,000 volts, which would destroy your charge capacitor. Since it comes in a pack of two, maybe the other one could be used to energize an electric fence? I know nothing about electric fences or what voltage they use, but I would hazard a guess that the circuitry is similar (flyback transformer design), and then all you would need is the right kind of wire and some insulated stakes.An electric fence is an interesting idea, provided it doesn't ignite dead leaves and create a fire. Not sure whether or not that's even a risk. I presume that professional electric fences wouldn't do that.
@NeverDie said in Most reliable "best" radio:
Will a firecracker actually kill a mole?
I'm not sure. But the MoleCat100 uses the blast from a 22 blank, and that has to be close to the concussive force of a firecracker. Being under the dirt by about 4" has to also help in rendering an effective shock wave since dirt is far less compressible than air.
@NeverDie said in Most reliable "best" radio:
The key seems to be charging high voltage capacitors, so that enough current is released at 500v when triggered.
Smoking Cool, and yea, probably dangerous. I was playing with flash bulb circuits from disposable cameras as a potential igniter. I accidently shorted a loaded circuit, and the thing burned a hole in my screw driver. Stunned and temporarily blinded, I put it away immediately and haven't gone back since. I don't think the 500 V device would work on moles; they do their foraging in their tunnels. Probably grubs and worms. Maybe they come out at night?
MouseTrapMonday has probably featured this 500 V device. He has quite a collection.
The Comidox 15KV looks like fun, and again dangerous. Glad to see that the thing comes disassembled. Assembly provides some knowledge requirement at least.
My electric fence is this one. It seems to have internal circuitry that limits grounding problems. The thing sends pulses at about 1Hz. Using a blade of grass, or green straw one can feel the pulses. I've had branches fall on the fence and pin it to the ground without resulting in problems so far. It would be fun to do a tear-down to learn how they work... but I've got these radios to play with.
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@Larson Do you have any links to this please? I found next doors 2 new cats killing 2 young birds they had paicked out of the tree and onto my lawn. The owners are un-cooperative on the issue and the cats have been using my garden as their own litter tray..... Garlic, chilli powder and vinegar have had no effect so I need to up the game!
@skywatch said in Most reliable "best" radio:
Do you have any links to this please?
Sure, Here it is on Amazon. I got mine at Coastal Farm and Ranch. While I'm now using it for skunks and racoons, I initially used it on the swim platform of my old wooden boat that was a party scene for sea otters. They can really stink up the boat after a winter.
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@skywatch said in Most reliable "best" radio:
Do you have any links to this please?
Sure, Here it is on Amazon. I got mine at Coastal Farm and Ranch. While I'm now using it for skunks and racoons, I initially used it on the swim platform of my old wooden boat that was a party scene for sea otters. They can really stink up the boat after a winter.
@Larson Since it's fed by AC from the wall, I'm guessing it's a relatively straight forward transformer based design rather than a flyback circuit, but I'm no expert in such things. I presume there's some kind of circuit in addition which renders it safe and non-lethal. Probably best to go with something known to work safely like that for an electric fence and not go the flyback transformer route, especially since the price is so low to begin with.
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@Larson Since it's fed by AC from the wall, I'm guessing it's a relatively straight forward transformer based design rather than a flyback circuit, but I'm no expert in such things. I presume there's some kind of circuit in addition which renders it safe and non-lethal. Probably best to go with something known to work safely like that for an electric fence and not go the flyback transformer route, especially since the price is so low to begin with.
@NeverDie I wouldn't know as I haven't studied power supplies outside of the engineering fundaments, yet. There is a version of these fences that use car batteries & solar charging. So they probably use different transformers.
I sure hope we didn't stink-up your thread with all this rodent-talk.
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@NeverDie I wouldn't know as I haven't studied power supplies outside of the engineering fundaments, yet. There is a version of these fences that use car batteries & solar charging. So they probably use different transformers.
I sure hope we didn't stink-up your thread with all this rodent-talk.
@Larson said in Most reliable "best" radio:
I sure hope we didn't stink-up your thread with all this rodent-talk
No worries. I'm not a stickler for staying on topic. I always say go where the interest is.
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@NeverDie said in Most reliable "best" radio:
Will a firecracker actually kill a mole?
I'm not sure. But the MoleCat100 uses the blast from a 22 blank, and that has to be close to the concussive force of a firecracker. Being under the dirt by about 4" has to also help in rendering an effective shock wave since dirt is far less compressible than air.
@NeverDie said in Most reliable "best" radio:
The key seems to be charging high voltage capacitors, so that enough current is released at 500v when triggered.
Smoking Cool, and yea, probably dangerous. I was playing with flash bulb circuits from disposable cameras as a potential igniter. I accidently shorted a loaded circuit, and the thing burned a hole in my screw driver. Stunned and temporarily blinded, I put it away immediately and haven't gone back since. I don't think the 500 V device would work on moles; they do their foraging in their tunnels. Probably grubs and worms. Maybe they come out at night?
MouseTrapMonday has probably featured this 500 V device. He has quite a collection.
The Comidox 15KV looks like fun, and again dangerous. Glad to see that the thing comes disassembled. Assembly provides some knowledge requirement at least.
My electric fence is this one. It seems to have internal circuitry that limits grounding problems. The thing sends pulses at about 1Hz. Using a blade of grass, or green straw one can feel the pulses. I've had branches fall on the fence and pin it to the ground without resulting in problems so far. It would be fun to do a tear-down to learn how they work... but I've got these radios to play with.
@Larson said in Most reliable "best" radio:
MouseTrapMonday has probably featured this 500 V device. He has quite a collection.
He's the one who demonstrated the dead fall skunk killer. He's also demoed some no-spray catch-and-release traps, but I don't see those as practical for anyone but the pro's. The way they work is interesting though: supposedly a skunk has to be able to raise its tail to spray, and the no-spray traps don't give them enough room to do that. The downside is that once you release a skunk from the no-kill trap, it can raise its tail and spray you, which is what happened to him in one of his videos.
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@Larson said in Most reliable "best" radio:
MouseTrapMonday has probably featured this 500 V device. He has quite a collection.
He's the one who demonstrated the dead fall skunk killer. He's also demoed some no-spray catch-and-release traps, but I don't see those as practical for anyone but the pro's. The way they work is interesting though: supposedly a skunk has to be able to raise its tail to spray, and the no-spray traps don't give them enough room to do that. The downside is that once you release a skunk from the no-kill trap, it can raise its tail and spray you, which is what happened to him in one of his videos.
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@NeverDie Hilarious.
Release problem: Nothing that a remote, a servo, a relay, and a radio couldn't solve. All of which would get sprayed anyway. Hmmm...
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@Larson said in Most reliable "best" radio:
Hilarious
Uh... after finding and watching the dead fall video, I downgrade my "Hilarious" comment to "Interesting". Back to the joy of radios!
@Larson said in Most reliable "best" radio:
@Larson said in Most reliable "best" radio:
Hilarious
Uh... after finding and watching the dead fall video, I downgrade my "Hilarious" comment to "Interesting". Back to the joy of radios!
I know what you mean. Not sure why, but even if the crush physics are equivalent, somehow his design does seem more disturbing than having a giant falling bolder do the dirty work. On the other hand, at some level it's no worse than road kill, which happens all the time, and most people seem relatively dismissive about that.
In any case, thanks for your post and info regarding the electric fence.
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As a first pass I tried running the RadiolLlb on these two 20dBm nRF24L01's with the default settings:
and although they work fine at closer ranges, they delivered zero packets (i.e. total fail) along my worst-case transmission path. Make of that what you will. I'll see if I can possibly tweak some settings for a better result and then re-test, but those are the early results. I thought them worth testing because many people here like the nRF24L01 radios and because those radios do have good support for over-the-air updates on the atmega328p.To be fair, there do exist some nRF24L01 modules on Aliexpress with even higher transmission power, so maybe a pair of those would cut the mustard.
I purchased them on amazon, mainly because I could receive them a lot faster than ordering something from China: https://www.amazon.com/dp/B07QC1SXJ8?psc=1&ref=ppx_yo2ov_dt_b_product_details
[Edit: same results even if I reduce the datarate to 250kbps. ]
Well, too bad. They do work for short range. Although this isn't rigorous testing by any means, I'm concluding that long-range for the nRF24L01, or other impairments, is essentially out of consideration Its niche is short-range, and for non-amplified versions preferably line-of-sight short-range. Sorry if that seems harsh, but for a comparison of different radio modules, somebody has to call it--and that's how I'm calling it. If somebody has a better nRF24L01 module that they feel would test better, please make a post and let us know what it is.
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Surprise! I'm getting it the nRF24L01 modules to send and receive, even along my worst-case transmission path, though for some reason ack's aren't being received along that worst-case path. Not sure why there would be an asymetry like that. Apparently the RadioLib library didn't default to full transmission power, because when I set transmit power to 0dB (which gets amplified by the PA), I'm now getting great radio communication. And this is the 2.4Ghz band, no less. Who would have thought? I'm flabbergasted. If anyone wants to replicate, I've posted my modified RadioLib sketches to source-code tab of the openhardware.io project for the nRF24L01 adapter.
Even if I increase the datarate to 1mbps, the majority of the packets are still getting through. This may turn out to be a closer horserace than I had originally thought: it may yet require some careful measruements to separate out the winner.
[Edit: As a result, I just now ordered some of these E01-2G4M27D: https://www.aliexpress.com/item/3256801616913450.html?spm=a2g0o.order_list.0.0.24f21802jP9dtI
presently on sale for $4.34 each with free shipping, which allegedly contain TCXO's and, hopefully, should be a further step-up in performance. In fact, these may be the top-end of what's currently available on the market in the nRF24L01 series.Now the long wait for them to arrive....]
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Surprise! I'm getting it the nRF24L01 modules to send and receive, even along my worst-case transmission path, though for some reason ack's aren't being received along that worst-case path. Not sure why there would be an asymetry like that. Apparently the RadioLib library didn't default to full transmission power, because when I set transmit power to 0dB (which gets amplified by the PA), I'm now getting great radio communication. And this is the 2.4Ghz band, no less. Who would have thought? I'm flabbergasted. If anyone wants to replicate, I've posted my modified RadioLib sketches to source-code tab of the openhardware.io project for the nRF24L01 adapter.
Even if I increase the datarate to 1mbps, the majority of the packets are still getting through. This may turn out to be a closer horserace than I had originally thought: it may yet require some careful measruements to separate out the winner.
[Edit: As a result, I just now ordered some of these E01-2G4M27D: https://www.aliexpress.com/item/3256801616913450.html?spm=a2g0o.order_list.0.0.24f21802jP9dtI
presently on sale for $4.34 each with free shipping, which allegedly contain TCXO's and, hopefully, should be a further step-up in performance. In fact, these may be the top-end of what's currently available on the market in the nRF24L01 series.Now the long wait for them to arrive....]
@NeverDie said in Most reliable "best" radio:
If anyone wants to replicate, I've posted my modified RadioLib sketches to source-code tab of the openhardware.io project for the nRF24L01 adapter.
That is my aim (to replicate). I've got these radios on order, but from China.
@NeverDie said in Most reliable "best" radio:
Not sure why there would be an asymetry like that.
I'm thinking... maybe because of the compounded probability of the second (ack) transmission? Maybe having a secondary transmision counter for the ack would help? I'll play with it if I'm not too late. As said, you move fast.
