Does this pass the Erco test?

pmrobert

What say the peanut gallery?

http://www.ebay.com/itm/Arduino-NRF24L01-2-4GHz-Antenna-Wireless-Transceiver-Module-For-Microcontroll/310670158878?_trksid=p5713.m2061&_trkparms=aid%3D333008%26algo%3DRIC.MBE%26ao%3D1%26asc%3D358%26meid%3D3958393078216699423%26pid%3D100041%26prg%3D1188%26rk%3D4%26rkt%3D9%26sd%3D130905531225%26

Datasheet: http://www.nordicsemi.com/eng/Products/2.4GHz-RF/nRF24L01P

GordonMcComb

Doubt it has any FCC certifications, but price alone I'm sure it passes the Erco Test. Anything that's less than the cost of a Big Gulp is about the only requirement.

Duane Degn

No way! Not with $2 shipping. There are many better deals for those around.

I do think they're very cool transceivers.

I'll try to find a better deal to post.

Duane Degn

How about five for the price of two?

If you move up to ten at a time they drop to about a dollar each.

Duane Degn

BTW, There is a driver available to use these with the Propeller.

Ron Czapala wrote code to use these with the BS2.

xanadu

Duane,

How is the range on these? Can they penetrate at least one interior wall in a house?

erco

I'll always defer to Duane on these wireless modules. But it's a real honor to be singled out as the resident cheapskate!

Duane Degn

xanadu wrote: »

Duane,

How is the range on these? Can they penetrate at least one interior wall in a house?

It's been a while since I've tested the range of these things.

I think my range tests were mainly concerned with the SparkFun Nordic fob (I tried to find a link but it looks like SparkFun no long keeps as many retired items on their server). I walked around our house pressing the Nordic fob and I could only find a couple of places where the transmission didn't get through. The time the transmission has trouble where when a heavy appliance was between the two transceivers. The refrigerator, oven and water heater were enough to block the signal but the transceivers did pass through up to three indoor walls.

While in general the range seems to be pretty good, I have had trouble with the transceivers when they were in the same room without any walls between them. I've noticed a single human body can be enough to block the transmission if the stars are aligned the wrong way. I think the main problem one would have with these transceivers is interference from other 2.4GHz signals.

One more note. I've had several wireless projects which worked great on the bench but did not work when I used batteries and a switching regulator. Switching regulators can cause all sorts of RF interference problems.

Duane Degn

I previously (in this thread) neglected to mention I have support documents to these nRF2401+ transceivers at the bottom of post #1 of my index. I usually also keep a link to an ebay seller of these transceivers in post #1. I just noticed my current link it to an out of date page. I'll update the link now.

xanadu

Duane thanks I was thinking a lot about your results based on the physicality.

It's hard to say for $10 I can get 10 anything else, that is for sure. Given the price, power consumption, size and integrated antenna I guess you really can't ask for penetration through walls. 2.4ghz is kind of crowded around these parts, I guess if they aren't centered on a single freq they should be okay. Hey do you know if... never mind I'll leave you alone and check out the datasheet hahaha.

Also, I'm sure these qualify for the "Erco Test", pending his written seal of approval of course. There is already an Object written for them, Duane has them, you probably won't find them cheaper.

If I get one I'll put it in my cage and run a RF spectrum analysis and get back to everyone on using these in 2.4ghz spectrum commercially.

I've been doing a lot of RF spectrum analysis lately and 2.4ghz is starting to look like the worst possible thing you could possibly use commercially. Sure at home things are different but god forbid someone build a sweet robot that doesn't work at the science fair cause some idiot is running 800mw 2.4ghz wireless video, etc...

prof_braino

N00b questions here:
Q1: These are trancievers, so they talk to each other, yes?
Q2: They are 2.4Ghz, can they talk to Wifi, as in my wireless router? Maybe, with appropriate driver? No?

Duane Degn

prof_braino wrote: »

N00b questions here:
Q1: These are transcievers, so they talk to each other, yes?
Q2: They are 2.4Ghz, can they talk to Wifi, as in my wireless router? Maybe, with appropriate driver? No?

Correct on both answers.

Here's a screen capture from the last video in my robot remote thread.



The data across the bottom of the screen is produced locally by reading the PlayStation 2 controller's output. However the data Angle, Magnitude, Rotation and Rx Hz is data being sent from the robot. While I have had this portion of the remote working in the past, I haven't gotten the wireless communication portion to work correctly since I've overhauled my touchscreen program to read the various menu data from a SD card.

Presently my Mecanum wheeled robot is controlled with a Spektrum RC receiver. My plan is to switch back to use these Nordic transceivers so information from the robot can be sent back to the controller.

My latest Nordic driver isn't working well. Something in my code is slowing down the rate of communication. The new driver is almost entirely written in PASM so it should be smoking fast. Unfortunately if I don't add some delays, the transceivers don't communicate with each other. I need to spend some time with my logic analyzer to see what I'm doing wrong. Fixing the Nordic software is a high priority but it's not yet the highest priority of my various projects.