Please don't double space your sentences. It makes it very hard to read.
I am using nRF24's for controlling an 00 Gauge model train. You can see some pictures in the first Post in this RMWEB thread
I am using an Attiny1634 with the nRF24 and a Pololu DRV8833 motor driver - that's the vertical board in the 4th picture.
The standard nRF24 module measures about 29mm x 15.5mm and the antenna is an integral part of the PCB. I have reduced the length by about 7mm by sawing off the antenna part of the PCB and soldering on a short wire for an antenna - the vertical brown wire in the image.
I have never tried a coin cell battery. I have the notion that they cannot produce enough current - but I may easily be wrong.
Existing key/object trackers such as the Tile use BLE and run for several months on a single coin cell by sleeping for 99% of the time. They only wake up briefly to listen for commands from the base station, and then only transmit data when requested to do so.
Useful for finding lost keys, but not much use if you are tagging things that quickly go out of range because of theft as it may take a couple of minutes for the base station to notice that the tag is no longer responding.
Existing key/object trackers such as the Tile use BLE and run for several months on a single coin cell by sleeping for 99% of the time. They only wake up briefly to listen for commands from the base station, and then only transmit data when requested to do so.
Useful for finding lost keys, but not much use if you are tagging things that quickly go out of range because of theft as it may take a couple of minutes for the base station to notice that the tag is no longer responding.
Thanks so much for the replies everyone, it's really jogging my mind! I'll stop with the double spacing.
I'm not worried about theft so much as remaining within range. It's totally fine if it only listens for commands every minute or two. Those tracker devices would be perfect for my application but they're so expensive and I really don't need the Crowd GPS stuff (although it would be an added feature, which is cool). What's inside of those little trackers? And would it be possible to replicate something like that using the cheaper RF technology? I'd be able to manage a short antenna to increase range to around 100m in open space.
Basically, I need it to detect range within 100m, and have a battery life of at least a few months. It will only be in use 4 hours per day, 2-3 days per week. I would also like the base device to be able to detect 6, 12, or 18 of the trackers all within a few seconds of each other.
Whandall:
For applications like this it would be smaller to use a nRF24LE1 if you want to be NRF24L01+ compatible.
After reading up on that, it says its only 4mm x 4mm, is this component functional on it's own or do I need it to attach to an other board? I assume it needs a board and battery. Could it be that simple? The 4x4mm piece, a battery, and an antenna?
And to be clear, it's ok if the tracker exceeds 100m, I just need the base unit to notify me within a minute or two.
Both nRF24LE1 and nRF24LU1+ have a combination of nRF24l01+ and a small MCU in one package.
I think the main difference is the USB interface that only the nRF24LU1+ has.
(For both there is no Arduino environment (I know of), you have to use different tools)
Maybe that board #3 is already small enough for you.
You could design a small board yourself, you see from the product #3 I posted above,
that there is not much peripheral stuff needed.
If you want to make your own modules, you could start a kickstarter project to get volume.
If they are neat and cheap, I would buy some.
Whandall:
Both nRF24LE1 and nRF24LU1+ have a combination of nRF24l01+ and a small MCU in one package.
I think the main difference is the USB interface that only the nRF24LU1+ has.
(For both there is no Arduino environment (I know of), you have to use different tools)
Maybe that board #3 is already small enough for you.
You could design a small board yourself, you see from the product #3 I posted above,
that there is not much peripheral stuff needed.
If you want to make your own modules, you could start a kickstarter project to get volume.
If they are neat and cheap, I would buy some.
This is looking good. Thanks for your input. So if there is no Arduino environment, you mean there's no codes on GitHub to copy? Or it just isn't compatible at all?
I'm willing to write my own code but can Arduino Uno be used for the base unit? And what would replace Arduino in the remote transceiver (Rx?)? That is, what would be a good alternative tool?
Before you go spending money on this, you had better have the answers to these questions (extracted from your posts):
Can I rig a system that is the size of a US Quarter or smaller?
It needs to be able to be located within 100 meters.
The antenna can actually be excluded from the Quarter requirements.
It is ok if it only listens for commands every minute or two.
Have a battery life of at least a few months.
It will only be in use 4 hours per day, 2-3 days per week.
The base device to be able to detect 6, 12, or 18 of the trackers all within a few seconds of each other.
It's ok if the tracker exceeds 100m, I just need the base unit to notify me within a minute or two.
My comments:
Doubt it. The CR2032 battery is already larger than that limit
Anit 'gonna happen. A bare NRF24L01+ chip has a range of about 10 meters with a pc board antenna.
Good but not sure it matters
Good, it conserves battery life
Possible, maybe, no power buget as yet
Good but how do you turn it on and off?
Possible
So they need to ping the base every 1/2 minutes and when they disappear, they're out of range?I'm mostly concerned with the distance. The long range NRF24L01's use a linear power amp for the output.
I don't see you pulling this off without the help of a very skilled UHF RF design engineer... for either an antenna design or a power amp to get you to the range you need. After the range issue, it becomes a battery issue...
