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I agree with zborgerd, LS guy's answer is more about compliance than anything else.

They just don't want people to mod their stuff.

 

This module has to work with antennas from different manufacturers and it's the antenna that has to match, you don't have any trimmers on the module. Unlike in ham radio where matching is done on the transmitter side, matching in modules like that should be done on the antenna side. So why would they design PCB antenna that requires changes in the circuit?

It just makes sense to adjust PCB antenna's dimensions and have a module design that is universal.

In any case, there will never be a perfect match because antenna's environment will affect it's impedance.

I think I am safe in assuming that this simple mod will do the trick.

There's only one way to find out, mod one module and test it against the original one.

 

Also, if you look at Microchip's modules mentioned above, the only difference between MRF24WB0MB and MRF24WB0MA is the position of capacitors.

 

And here's a quote from cc2520's datasheet

9.7 Antenna Considerations

The reference design contains two antenna options. As default, the SMA connector is connected to the balun through a 0? resistor. This resistor can be soldered off and rotated 90

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I came across these promotional items the other day:   http://components.arrow.com/part/detail ... 91464N1044   Try not to be to greedy, and shipping isnt so cheap!   they are difficult to work

Hello Kenemon, I'm willing to sponsor a batch of 10PCBs from Seeed, otherwise what good are the adverts. Currently Hyland Savior is also trying to make one here which will also be getting sponsored.

I took a closer look at the antenna and I think it should be pretty easy to use the built-in one. It appears that the only part missing is a little piece of shorting chip (judging by the picture of th

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So why would they design PCB antenna that requires changes in the circuit?

It just makes sense to adjust PCB antenna's dimensions and have a module design that is universal.

 

Here's another question... Why put an antenna on a PCB at all when it can't be used? It's there so that they only have to fabricate a single PCB for all of their modules (a single footprint), and they simply have to add the appropriate parts when they fabricate the module. The matching network on the CC2591 is integrated. I cannot see how there could be any substantial differing components between the two modules.

 

There are no resistors or caps on the PCB that cannot be identified and compared between the two boards. Besides... We have this:

 

Reference Design: http://www.ti.com/tool/cc2520-cc2591em_rd

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The LS Research module has a Murata LDB182G4520C-110 Balun (50/200).

 

So here's an even better reference design: http://www.ti.com/tool/cc2530-cc2591em-rd

http://www.ti.com/litv/zip/swrc171

 

For all intents and purposes, the TI reference design in the CC2530-CC2591 Evaluation Module Kit appears to be identical to the RF portion of LS Research module.

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Regarding the antenna considerations, there are more details here: http://focus.ti.com/general/docs/litabs ... r=swra308a

 

Page 19 points to two antenna design considerations:

 

Antenna selection guide: http://focus.ti.com/general/docs/lit/ge ... er=SWRA161

Inverted F Antenna: http://focus.ti.com/general/docs/lit/ge ... er=SWRU120

 

Not sure that these were posted here, but I figured that I should bring them up so that we have them as a reference.

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Just poking around, I've observed that LS Research appears to have a business model that involves the following:

 

1. Create modules that are "certified" in their labs. The owner of the company appears to have started a certification company in the 90's (per their homepage).

2. Modules have closed-source firmware. It looks like the files that they provide on their site are based on TI's Media Access Control stack 1.3.0. They give you the option to buy the source and design files if you wish to use their modules in your products, or you can buy the source and design files to use to create your own products. They will certify your modules for a fee.

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I am "actively" working on these babies. I managed to get the thing mounted and wired up using the "minimum" connections, which did not require any components besides LED's and 2 buttons. The firmware which is loaded, modflex, seems to work fine, but I have not been able to connect with my 2531 dongle.... yet. My efforts to load SimpliciTI have also been unsuccessful. I found a code for IAR which allows for larger code, but as with the CCS version, I cannot find the device when flashing. I will post more regarding this progress......

 

Thanks. KB

 

Fri Dec 30, 2011 09:20:37: Interface dll version 2.4.8.2

Fri Dec 30, 2011 09:20:37: Invalid parameter(s)

Fri Dec 30, 2011 09:20:41: Fatal error: Could not find device (or device not supported) Session aborted!

Fri Dec 30, 2011 09:20:41: Failed to load debugee: C:\Users\Ken\Desktop\LSR Simplicity\480-0013-R0.2\SimpliciTI-IAR-1.1.1\Projects\Examples\SRF05_MSP\Simple_Peer_to_Peer\IAR\ProFLEX01\Exe\Simple_Peer_To_Peer.d43

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got some drivers swappped and i can flash again. still no ccs or iar....

 

Fri Jan 06, 2012 07:59:03: Interface dll version unknown

Fri Jan 06, 2012 07:59:04: Device : MSP430F5437

Fri Jan 06, 2012 07:59:04: External voltage : 3.3 V

Fri Jan 06, 2012 07:59:04: VCC voltage : 3.3 V

Fri Jan 06, 2012 07:59:06: Fatal error: The Object file contains features not suported by the driver. Session aborted!

Fri Jan 06, 2012 07:59:06: Failed to load debugee: C:\Users\Ken\Desktop\LSR Simplicity\480-0013-R0.2\SimpliciTI-IAR-1.1.1\Projects\Examples\SRF05_MSP\Simple_Peer_to_Peer\IAR\ProFLEX01\Exe\Simple_Peer_To_Peer.d43

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ANother "gift" from Arrow, for less than a penny:

 

comes with two boards, batteries, cables, and CD

 

post-1413-135135533578_thumb.jpg

 

post-1413-135135533582_thumb.jpg

 

get them while theyre hot, and try to help me program these. Cant get SimpliciTI workin with IAR. I am working on a CCS port.

 

KB

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