NEW: WiPy 2.0 - shipping 10 Oct 2016
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
With just the board, I would expect the usual situation: between 10m and 100m, depending on the crab that is between transmitter and receiver.
There are some challenges on how far WiFi can reach, but that was in in plain air, with special antennas (see e.g. https://www.wired.com/2007/06/w_wifi_record_2/). And a lot of interesting reading in the net.
There are some challenges on how far WiFi can reach, but that was in in plain air, with special antennas (see e.g. https://www.wired.com/2007/06/w_wifi_record_2/). And a lot of interesting reading in the net.
- pythoncoder
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Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
Indeed, I have seen such reports before. But look at his aerials!
The claim of 1KM "out of the box" is so radical that I very much want to know the test conditions. The difference between 100M and 1KM is 20dB in link budget which doesn't sound much if you say it quickly But it means a factor of 100 in terms of receiver sensitivity; you can't multiply the transmitter power by 100 a) for legal reasons and b) because you can't change the AP at the other end of the link.
Up to now the only way you can get a 20dB improvement in link budget is by using directional antennas which is inconvenient.
So I really want the developers to tell us how this is achieved: it's seriously difficult while maintaining standards compliance.
The claim of 1KM "out of the box" is so radical that I very much want to know the test conditions. The difference between 100M and 1KM is 20dB in link budget which doesn't sound much if you say it quickly But it means a factor of 100 in terms of receiver sensitivity; you can't multiply the transmitter power by 100 a) for legal reasons and b) because you can't change the AP at the other end of the link.
Up to now the only way you can get a 20dB improvement in link budget is by using directional antennas which is inconvenient.
So I really want the developers to tell us how this is achieved: it's seriously difficult while maintaining standards compliance.
Peter Hinch
Index to my micropython libraries.
Index to my micropython libraries.
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
If we are picking nits, I'd like to direct your attention to the fact, that they didn't write "1km" (kilo-meter), as you seem to be interpreting this. They wrote "1KM". What unit is "KM" I have no idea, but it may as well be that 1KM is equal about 100m, and then everything is right.
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
I know, they specified it in Karat-Molars!
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
Not really, as it would also mean that we are all living in different spacetime references...What unit is "KM" I have no idea, but it may as well be that 1KM is equal about 100m, and then everything is right.
My bet is on KM = kilo milimeters
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
It's a capital K, though, so 1024 millimeters?
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
They are from Amsterdam, Netherlands... they got neither mountains nor hills... so no real sense for range!
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
Sorry for being off topic, just want to comment LoRa. Personal experience is that we can track small private airplane with LoRa. 50km is reliable and stable, getting cca. -4 dB S/N ratio while system limit is around -15dB using a small 0 dB gain stick antenna inside of cockpit. Changing antenna to a cca. 3dB gain and installing tracker outside would make it better. Why only 50km? Because it was the biggest distance during test flight airplane made In larger distance flight height can be an issue due to distance to horizon.
Send me a PM if you need details.
Send me a PM if you need details.
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- pythoncoder
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Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
@bmarkus I've read a number of accounts of long range communication using LoRa. IIRC the spread spectrum modulation method achieves a 20dB improvement in link budget offering an immediate improvement unavailable to WiFi. While LoRa is carrier frequency agnostic, I gather most physical realisations work at 433, 860 or 916MHz frequencies offering further range improvements especially in urban environments.
I think it's an exciting technology, especially if it's deployed by enthusiasts to provide free town and city wide low bandwidth IOT internet access https://www.thethingsnetwork.org/.
I think it's an exciting technology, especially if it's deployed by enthusiasts to provide free town and city wide low bandwidth IOT internet access https://www.thethingsnetwork.org/.
Peter Hinch
Index to my micropython libraries.
Index to my micropython libraries.
Re: NEW: WiPy 2.0 - shipping 10 Oct 2016
In Europe 99.9% of networks are on 868MHz. Right, your end device must be registered in a network which can be either a public service or your own network. You can register a small private network at https://loriot.io free for 1 gateway and 10 end devices. Good point is that free networks provide roaming for others. Also, large network operators may decide to offer roaming. For example Budapest and surroundings are covered by independent networks with roaming, and I see roaming in e.g. Linz and Prague for my devices. It is great!pythoncoder wrote:@bmarkus I've read a number of accounts of long range communication using LoRa. IIRC the spread spectrum modulation method achieves a 20dB improvement in link budget offering an immediate improvement unavailable to WiFi. While LoRa is carrier frequency agnostic, I gather most physical realisations work at 433, 860 or 916MHz frequencies offering further range improvements especially in urban environments.
I think it's an exciting technology, especially if it's deployed by enthusiasts to provide free town and city wide low bandwidth IOT internet access https://www.thethingsnetwork.org/.
For a gateway you need a Raspberry Pi and a radio board offered by several vendors. So it is not so difficult to start.
Tiny Core Linux (piCore) developer
HAM radio call: HA5DI (Béla)
HAM radio call: HA5DI (Béla)