super long range transceivers - Page 1
Forum section: electronics / projects

author: KTP
author_rank: Frequent Contributor
timestamp: October 07, 2010, 06:08:42 pm
content: I have been playing around with the TI EZ430-2500T wireless transceivers (2.4Ghz) which come with a fairly poor chip antenna giving a range of maybe 20 meters if you are lucky.I just tried out the Anaren 900mhz modules (A1101R09C) that are direct drop in replacements for the TI board. The ones I got have a U.FL connector (soooo tiny) so I ordered two ISM band antennas from digikey (931-1085) which have a small pcb antenna and a cable with a U.FL connector.Damn! I ran the TI temp monitor demo program that comes with the EZ430-2500T and took one of the Anaren modules a few blocks away from the house. Came back and it was reporting the temperature with a signal strength of 44%. And this is with the laptop and one Anaren module indoors and the other one outdoors, so signals passing through one wall. And it isn't even a high gain antenna (I bought one other antenna I haven't tried yet which has a quite larger pcb on the 915Mhz ISM band and a gain of 1.5dBi.I am now thinking that several km range might be in the realm of possibility with these modules that are smaller than a dime. Pretty cool stuff. Now I just need to write a program to test data rate...

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 07, 2010, 06:53:53 pm
content: It's always surprising how much better 900MHz and 433Mhz is in a residential area (walls and floors). So this is just a CC1101 module. How much did you pay for these? If you check e-bay, there are usually CC1101 modules available. I was going to try a CC1101 solution about a year ago, but supply for a lot of TI stuff including the CC1101 dried up for a long time. If you want to roll your own, they have already tuned one chip baluns for the CC1101 on Digikey. Makes it real easy.I have the RF2500 as one of the transceivers I was testing and ya, they are generally well known for their poor antenna design. They hardly worked throughout my house.I hang onto my old 900Mhz Panasonic cordless phone, because the range is so much better than the 2.4Ghz I've tried.

author: KTP
author_rank: Frequent Contributor
timestamp: October 07, 2010, 08:22:11 pm
content: My local distributor got me a couple of samples for free to try out.I think the Anaren units are about $15 to $20 or so in singles. They are FCC certified, which is nice.

author: JohnS_AZ
author_rank: Frequent Contributor
timestamp: October 07, 2010, 09:52:18 pm
content: Have you got a good link to the anaren units?

author: KTP
author_rank: Frequent Contributor
timestamp: October 07, 2010, 10:35:28 pm
content: This is the page on Anaren with the little 1101 modules:http://www.anaren.com/content/File/AIR/AIRoverview.cfmI am using their module mounted on a board with a MSP430 such that it is a drop in replacement for the TI board:http://www.anaren.com/content/File/100909a-%20A1101R09C-EZ4x%20Prod%20Brief%20STD%20RES.pdfNote how incredibly tiny the actual transceiver is. Amazing stuff.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 07, 2010, 11:17:58 pm
content: Quote from: TheDirty on October 07, 2010, 06:53:53 pmi have modules using CC1101 assembled and tuned in China i guess, not working as expected, i'm not sure what went wrong. Ended up using even cheaper module right now. now this Anaren chip, quite interesting news, might be the next try out, next time.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 09, 2010, 01:25:17 pm
content: out of curiosity, i installedwigleon my phone and drove to the gas station just a few suburban blocks away. over 200 unique networks found! thats just wifi, no bluetooth, no cordless phones, no usb mice... it amazes me that anything works on 2.4ghz!-sj

author: Unknown
author_rank: Unknown
timestamp: October 09, 2010, 04:41:32 pm
content: All things equal, shorter wavelengths get more attenuated by traveling through something like concrete than longer wavelengths. Plus 2.4GHz is close to an absorption peak for water (microwave oven, 2.45GHz according to Wikipedia). Probably one of the reasons why it's unlicensed spectrum in most of the world is that it's not terribly useful for commercial applications like cellphones.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 09, 2010, 10:58:55 pm
content: I have this one that it does work very good ... but it came with poor quality of cable,and I had to replace it with true 2.4G cable ..You can find it on ebay ..

author: sonicj
author_rank: Frequent Contributor
timestamp: October 11, 2010, 09:39:15 am
content: if you use a u.fl to sma (or rp-sma) pigtail, you'll have access to a much broader range of available antennas. also makes building your own antenna much easier!u.fl to rp-smathat one is female to female, def want to check before ordering.*fixed bad link

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 11, 2010, 03:44:04 pm
content: I use these guys for cheap connector/antenna options for 900Mhz. These are SMA, not RP-SMA. Sorry, doesn't help with the U.FL connector.connectors:http://www.dealextreme.com/details.dx/sku.5173http://www.dealextreme.com/details.dx/sku.5160antenna:http://www.dealextreme.com/details.dx/sku.5237http://www.dealextreme.com/details.dx/sku.5279

author: sonicj
author_rank: Frequent Contributor
timestamp: October 11, 2010, 06:22:40 pm
content: *fixed the u.fl link above.i also use dx for cheap antenna stuff from time to time.

author: KTP
author_rank: Frequent Contributor
timestamp: October 13, 2010, 12:06:46 am
content: Quote from: sonicj on October 11, 2010, 09:39:15 amYes, I bought one of those from Digikey when I ordered the U.FL antenna I tested the modules with.Problem I am now having is I can't really think of anything super useful to build with these things. A 2+ mile range transceiver the size of a dime probably has some great criminal applications, but I am not into that. I think it is probably fortunate for the rest of the world that most of us EEs or aspiring EEs are pretty honest.Now if it had a 1000mile range I would be interested in making a little underwater explorer robot...perhaps solar powered, that could navigate the ocean currents and send back pictures of sea life or something in different parts of the world...

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 13, 2010, 02:19:39 am
content: I just have a small home network with my 900Mhz modules. With a simple network protocol you should be able to find lots of uses. Put one in the car and have an indicator in the livingroom/kitchen when the car signal is found for an indicator when the car is close. Helpful if you share a car with the Wife. You know they are getting close. Do the regular home automation stuff. I have an 'RF server' attached to my linux server so I can control and monitor stuff from the internet. I don't have much yet, but a garage node that gives me temperature, light, garage open status, and allows my to toggle the garage door button. Some light controls, and I'll probably make my Christmas lights controller into a node.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 13, 2010, 04:26:48 am
content: Quote from: KTP on October 13, 2010, 12:06:46 amunderwater is whole 'nother story! even trying to control an rc on the surface can be a challenge.i was thinking today that i'd like to build a rf controlled gate opener for my golf cart. rc'ing the golf cart itself is on my to-do list as well.interesting fact about RF & RC Submarines.... Tesla patented the concept of frequency hopping around 1900 while experimenting with his RC submersible.U.S. Patent 723,188&U.S. Patent 725,605