need transeivers for system development

RE: need transeivers for system development

T. Rooks — Mon, 28 Apr 2014 22:55:51 GMT

Thanks for all the advise.

I have decided to go with RS232 to RF transceivers.

I already have several MCUs to program in Basic for my private communications scheme.

Fare Thee Well,

Tim

RE: need transeivers for system development

Nguyen Hoan Hoang — Mon, 07 Apr 2014 04:12:35 GMT

Ok, if you prefer Zigbee then Atmel has MCU with Zigbee inside. They have both AVR & ARM core version. TI also has ARM Zigbee I think. Freescale also have something. Zigbee Stack software from Atmel is bad coding. TI is better, Freescale don't know. Atmel has free software development tools. Any ARM development can be done with Eclipse and GCC so it's also can be free. There are also Wifi solutions or just plain RF modem. :)

RE: need transeivers for system development

T. Rooks — Mon, 07 Apr 2014 03:54:16 GMT

Nguyen,

A follow up.

The 51822 is quite impressive.

I will not be able to use it though. I simply refuse to get off into Bluetooth.

There is way too much of it in all kinds of guises out there. It would not do for one use of it I did not know of to show up at a product demonstration and wreak havoc with my system. There are also other considerations of at least not making it easy for others to monitor and figure out things about my system.

(Most do not realize the implications of all those street level photos on g-o-o-g-l-e earth. Every neighborhood was also swept to identify whatever types of wireless systems were in that neighborhood and tie them to specific addresses.)

I will likely go with something like the 24L01 if I can find one that allows for network broadcast to all units like what was available on the XBee modules. Otherwise I will be stuck with a control unit with a lot of antennas sticking out of it with transceivers and processors for each of them.

I am certain I can do what is needed for the programming using an Arduino since it has been around a good while and there should be some code examples for me to study and adapt to my needs.

One thing about not having a lot of money to spend is that you have lots of time to figure out how to best spend the little money you have. ]8-(

Tim

RE: need transeivers for system development

T. Rooks — Sat, 05 Apr 2014 04:18:17 GMT

Nguyen,

Thank you for the additional info.

I like the idea of having processing power as pat of the Tx/Rcv units. I will have to study the specs for the unit and determine if other factors such as additional I/O and memory will suite my needs. Also Bluetooth is something new to me and I have no clue about how it operates or what it is capable of. Time constraints dictate that I stick with Basic programming if at all possible.

I am having to take some time away from my project to deal with a personal family matter and am not sure how long it will be before I can get back to working on it.

Thanks again,

Tim

You can teach an old dog a new trick but he might not remember it for very long.

RE: need transeivers for system development

Nguyen Hoan Hoang — Fri, 04 Apr 2014 18:36:52 GMT

The nRF51822 has ARM Cortex-M0 running at 16MHz that you can use without additional MCU. I don't think you can do ring topology with it though. You can get it to do star topology with one acting as Central and the others as Peripheral. It would not be difficult to implement your own protocol by using Buetooth custom service described in NAN-36.

RE: need transeivers for system development

T. Rooks — Fri, 04 Apr 2014 15:55:51 GMT

Ole,

Thanks for the info. -25 to +75C will do nicely.

I am giving serious study to the nrf24L01 or actually the newer version. Could you recommend a suitable (25 - 75 C) microcontroller and programming tool for programming everything in Basic

I am having trouble figuring out how to send a broadcast to multiple units at the same time.

The data in the broadcast is a crucial trigger that has to be received simultaneously by multiple remotes.

I was trying to do this with XBee modules even though they did not meet my temperature requirements just so we could put together a demonstration system. One of the three units failed with 8 hours and the two remaining had a .001 failure rate tor Tx/Rcv messages.

Being able to do this will in effect complete what I had developed with all the units hardwired together.

Also are there hobby/developer groups out on the web that you would care to recommend?

Thanks again,

Tim

RE: need transeivers for system development

Ole Morten — Mon, 03 Feb 2014 11:25:12 GMT

Your temperature requirements are pretty wide, and I actually don't think any of our current chips go from -50 to +85 degrees Celsius. The nRF24L01+ comes close at -40 to +85, but that's about it.

However, if you can limit your temperature range to -25 to +75 degrees Celsius, I'd recommend you to look at the nRF51822, which is an improved nRF24L01+ radio plus an ARM Cortex M0 MCU, giving a single-chip solution. The product specification is available here.

If -25 to +75 degrees is too little, but -40 to +85 is sufficient, the nRF24L01+ is our other option. The official specification is here (the one Brian linked to is an old, out-dated version), and as you can see this is a pure transceiver chip, that can be used from any microcontroller with an SPI interface. This has a slightly more limited radio, but should still be usable for your application.

RE: need transeivers for system development

T. Rooks — Sun, 02 Feb 2014 08:54:33 GMT

Brian,

Thank you for your quick response.

The part number you mentioned was indeed one of the reasons I came to this site to post an inquiry. Actually it was the older version of that part that had come up a time or two in my research.

It is indeed a fabulous part and if I had much deeper pockets my search could very well have ended here. In many cases there are whistles and bells all lumped together in the product that do not necessarily fit or even enhance what my design is about.

The process I am about at this time is not so much filling my shopping bag with the best available as it is with finding very good products that I can use in combination and can afford at this time. There is also the problem of new standards and methods that were heretofore unknown to me.

I am a bit curious though as to why the link you provided takes me away to another site entirely. Could you enlighten me a bit about that?

For now I am leaving my query open in hopes of gaining other inputs.

Thanks again for your response,

Tim

RE: need transeivers for system development

Brian — Sat, 01 Feb 2014 08:33:49 GMT

Wow Tim, looks like you have quite a beast to tackle! These don't have the ideal included MCU, but I've just been playing with the nRF24L01+, and they can handle almost all of the protocol for you. A poke around the datasheet will give you a great idea of how useful they will be to you. With two-way payloads, one could easily keep these time-synchronized, and a decent antenna (biquad, perhaps) would increase the range, as well as choosing an open 2.4 GHz channel, but it may require amplification to get your 100 meters. I'm not sure of the true limits of their range, that's up to testing.

I've not done anything of the standard you've described, this is just where I would start out of the gate. Good luck!

-Brian