Oddly enough, I am helping a friend do a colour cycling "light-show", and he wants to control it over Bluetooth :-)
Thinking about it, it may be cheaper to get an ordinary ethernet shield, and an ethernet wifi bridge or router than a WiShield!
Wireless communication options for Maple
(48 posts) (11 voices)-
i suppose this depends on where you are? in the US, sparkfun sells ethernet shields for $45.95. WiShield 2.0 from asynclabs is only $55. is an ethernet wifi bridge less than $10? seems ridiculously cheap to me, but hey, it could be.
and,
perry's got LEDs hooked up to a maple+wishield that go through the color wheel when the wireless network is up. makes it easy to tell when it's down :)
so this means the wishield library ports nicely then? (or maybe even "just works"?)
Posted 5 years ago # -
okay, I went to sparkfun and went nuts. I got:
Xbee/802.15.4 serial based solutions. 802.15.4 would be a very nice solution, but the the protocol stack is proprietary. Quick internet search brought me to http://freaklabs.org/. Xbee seems very popular with the Arduino crowd; and Xbee has an internet gateway device too.
The $5-$10 RF Link in 315 MHz. UART interface.
And the Nordic nRF2401A http://www.sparkfun.com/products/691.
I didn't bother looking at WiFi or Bluetooth.
Posted 5 years ago # -
gbulmer
Moderatorlarryang - Wow. Have fun!
There are a lot of zigbee and zigbee-like mesh network protocols. If I ever get around to making a robot swarm (unlikely in the next 6 months), I'll look a bit harder into mesh network radio. There are a few issues with managing latency. So I would prefer an open source stack like freaklabs, or tinyOS, preferably layered properly, so that the unnecessary parts can be thrown away :-)
Please forgive me for saying, much as I like Sparkfun, and the wonderful things they do for hobbyists, I think $19.95/ Nordic nRF2401A+ module is a lot compared to
http://shop.ebay.com/?_from=R40&_trksid=p5197.m570.l1313&_nkw=nRF24L01%2B&_sacat=See-All-Categories
where they are $7 each, or $12.95 for two
http://cgi.ebay.com/2-x-Newest-2-4Ghz-nRF24L01-RF-Transceiver-Module-/300452959863?pt=LH_DefaultDomain_0&hash=item45f4645677Anyway, please report back on what you decide works well. I think there will be plenty of interest.
I am intrigued by the STM32W, anyone experimented with it?
Posted 5 years ago # -
gbulmer
ModeratorI should have mentioned these folks
http://www.radiometrix.comThey make a huge range of wireless modules, with various interfaces from 'DIY modulation' to 'here's some data, get it there please'.
They make modules for lots of wavebands.
The CU Spaceflight folks used them on their 'near space satellites' (Helium balloons)
http://www.radiometrix.com/cu-spaceflight
CU Spaceflight reported balloon to ground, line-of-sight data transmission, using a hand held, directional antenna, at 600km (i.e. about 370 miles), on a legal waveband, with about 10mW of transmitter power in the balloon, though that was exceptional.May be interesting to someone.
Posted 5 years ago # -
gbulmer
Moderatori suppose this depends on where you are? in the US, sparkfun sells ethernet shields for $45.95. WiShield 2.0 from asynclabs is only $55. is an ethernet wifi bridge less than $10? seems ridiculously cheap to me, but hey, it could be.
I was thinking of one of these Freeduino ethernet shields:
http://www.nuelectronics.com/estore/index.php?main_page=product_info&cPath=1&products_id=4£12.50 GBP ~= $20 inc tax
and Amazon seems to have plenty of WiFi routers under $35, some under $30.
Posted 5 years ago # -
For wireless, I've been using this as a temporary solution until I can afford some XBee Pros.
http://www.seeedstudio.com/depot/bluetooth-bee-p-598.html?cPath=101_103
Fairly easy to set up, need to set up some library functions so I can do it all automated.
Posted 5 years ago # -
gbulmer
Moderatordoes anyone know of a transmitter capable of running on 9V batteries (and solar panels) that can transmit an RF signal over 99km? Preferably it would transmit 150km.
Under what circumstamces? Line of sight?
How often is the transmitter on? (Average, peak)
What is it transmitting? I.e. is it stero FM music, or data. If it's data, what data rate?How much power is available from the 9V batteries, and are the solar cells mainly there to recharge the batteries? How much power do you expect to get from the solar cells/day?
Can it use mobile phone, SMS, or a pager network?
Posted 5 years ago # -
I've seen these serial to bluetooth adapters on eBay which look promising.
Only $20 for a pair.
Posted 5 years ago # -
Silntknight
ModeratorActually, the MCU and transmitter will be in low-Earth orbit... Line-of-Sight, I guess so.
How often is it on? I'm not really sure. Every now and then. Preferably once per orbit (or per day if it is geosynchronous).
What is it transmitting? I'd like it to transmit picture data, but unless anyone also knows of a 2-5g camera I doubt that's going to happen. It'd likely transmit some kind of data to verify it is in space (pressure, temperature, light intensity, a signal to triangulate...) Data rate can be anything really. It would likely be very low to conserve power (or maybe I'm wrong in that assumption).
How much power is available? Well, 9V batteries weight too much, so I'm going with some super capacitors (5F/5V) and 3 Lithium Polymer button batteries. Solar cells would recharge the caps, but solar cells also might weigh too much, so I might not have any of those either.
It can use whatever transmission possible as long as I can receive it. I doubt cell/pager networks are active in space. They aren't even active on places 36,000 ft in the air. Thanks. I know this seems very haphazard and everything seems to weight too much, but that's actually just how it is. I have 19.9 grams to work within, and my MCU will take up 5g of that.Posted 5 years ago # -
gbulmer
ModeratorSilntknight
1. ask Amsat
2. look at pico satellite projects
3. http://www.srcf.ucam.org/cuspaceflight/wiki/doku.php shows some ideas
4. Maybe http://www.radiometrix.comI doubt cell/pager networks are active in space.
Why would the radio spectrum they use not extend to low-earth orbit?
Aside from frequency, they are like any other radio system you might use.
What causes you to think they wouldn't work from space?They aren't even active on places 36,000 ft in the air.
What causes you to believe that?
Have you ever switched on a mobile phone at 36,000 feet? I've sat next to a Blackberry user who was furiously typing emails, and responding to new ones while in flight.I believe real events, where people used their mobile phones from a plane were widly, and sadly, reported.
Have you seen this video, it was reported on USA news channels:
http://www.youtube.com/watch?v=zku7R_GftV4
a father and son launched an iPhone and video camera into 'space'MIT did this: http://space.1337arts.com/
Mobile phone network operators don't like mobile phones at 36,000 feet because their base-station algorithms don't work well, but I believe phones get through. Do you have a pilot friend you can ask?
Airlines don't like mobile phones at 35,000 feet, partly because they like to charge $1/minute to use their phones.
Do I believe the planes instruments stop working when a mobile phone is on?
Let me think, hmmm ....
Might a 'very naughty person' put a mobile phone in luggage, and have it switch on in flight? Might some one have had a phone, but the on button got pressed in-flight? Hmmm?Of course, it is illegal to use mobile phones over some countries, for very rational reasons, but physics often ignores local laws.
I have 19.9 grams to work within
Contact Amsat, look up pico satellites.
I believe this is a well understood problem for those systems.IMHO, if your constraints are much worse than those folks, who are paying $100-$1000's/gram, a solution is probably out of your league, unless you have a comparable budget of $100-$1000's/gram
Maybe look at this 21gm board, and see what you could reduce:
http://www.srcf.ucam.org/cuspaceflight/wiki/doku.php?id=badgercub
I think there are quite a lot of options.Posted 5 years ago # -
mikep
MemberAnother cheap option might be the RFM12B modules from HopeRF.
They use SPI and work directly at 3.3V, range is about 100m outdoors.
They can be put into sleep mode for low-power scenariosThere is some extensive Arduino code (and hardware - JeeNode) available at http://www.jeelabs.org - he also implemented some basic ack protocol and encryption etc.
You can buy the modules separately at http://shop.moderndevice.com/products/rfm12b-radio
Mike
Posted 5 years ago #
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