I am doing it right now. Thanks for prompting me.

Active Robots Managing Director got back to me (yes in the evening!). He said they are for RS232 ports only. I think it means connects directly to RS232 with no such thing as a max232 (its got it onboard) on either end.

He was kind enough to offer an exchange for the other modules for me.

I think the problem is the way they advertised it. They put the data sheet for the single module for this one, which they modified quite a bit to make it compatible directly with RS232 port. Very misleading indeed.

 

Ok, I got them to work.

They dont need any RS232 level translator whatsoever, its all built in. BUT the input and output is both RS232.

This means unless I am connecting it direct to my PC, I will have to use a max232 with the uCs. A pity.
The baud rate is set at 19200 and I cant change it. Blueteeth, on the modules you have, were you able to change the baud rates?
Also, Does the internal buffer HAVE TO be full before it transmits all the bytes? Or does it transmit as soon as it received the data?

I have to weigh the pros and cons now. For that, I need blueteeths response to these questions and the ones above . Thanks

 

edit (4 seconds after posting):
LOL didn't see the second page of the topic..oh my..well I hope its still helpful!

Are you sure you've got all the rs232 settings right?
Do you know for sure that your comm port on yourPC is working correctly?

The software they provide in a zip file will help. It can at least test the board to see if everything is ok, and that its communicating. But for changing settings...baud, channel, power output, handshaking CRC etc.. etc.. you NEED that software. Otherwise you'll be using the config strings in teh datasheet and typing them in manually in hyperterminal

Even using the modules alone, I got stung by getting several of the individual modules..all with different channel settings...ergo, they would not talk to each other. I had to use the above software to set them all. I also recommend you read the datasheet for the exact module you have (thepart number is on the module ) As the 868/900Mhz ones, only have two channel settings available, 0 and 4.

Maybe so, but..its a learning curve :/ They are still usable of course...maybe not so easy to 'embed' them in a permenant app becauseof the rs232 transciever and the V-reg, but as a development tool, not so bad...saves you havingtoknock up a regulator everytime you want to use them. You could always solder small wires direct to the TX/RX pins, and maybe the handshaking lines toget direct access.

Handshaking lines been disabled? You can always re-enable them using the software they provide. You can change the baud, channel, RF power output etc.. even the CRC checksum length (8 or 16).

I don't tihnk the datasheet is 'irrelevent' at all. With the module alone the connection to a microcontroller is identical to the connection to a PC, the only difference being the rs232 level shifter in place. The datasheet provided by them is the same from lprs and provides all the info you need. Again, the only difference is the voltage regulator and the max232 on it.

Thats why I'm cautious about third-parties. But, I'm sure LPRS will be willing to help you...I phoned them up, and within 20 seconds the guy onj the end told me he was out of his depth and passed me on to someone else...the designer. Couldn't be happier with the service!

I have desoldered a total of 3 of them from boards I made which were 'destroyed' by customers, and you're right, its messy and a bitch to do, as the pins themselves are held on the module with solder, so they just come off.

[/quote]

During testing I didn't use an antenna at all, not even a wire, and I got about 10 metres out of it, with full RF power. With antenna's, a good 50 line of sight, and maybe 30 inside a factory (surrounded by EMI and metal). Although I didn't notice much of a difference in range between using a proper SMA 868Mhz antenna, with PCB strip lines, and using just a piece of wire (whip) 8.7cm long :/

I would say yes, you can connect TTL/CMOS, but use protection on the TX from the module, that is, the one coming 'from' the rs232 transciever, as it'll be +/- 7-12V and may fry something. A resistor and a transistor will sort it, or perhaps a voltage divider. I tihnk you can drive most RS232 devices with 0-5V providing the lead isn't too long <4 metres?

And as you may know, TTL UARTS use inverted logic when compared to RS232. The modules themselves use this, but as its going through a max232 (rs232 transciever) that will invert it, so to connect to a microcontroller, you'll needto 'invert it' again. A hassle I know, but a transistor inverter for both TX and RX would do the trick.

It may not be all bad. You could use 'that board' just at the PC end, and maybe buy an individual module to go on a robot, or some custom app. The transcievers rock as far as link reliability goes, as they can 'resend' information that get errors.

Good luck man,

Blueteeth

Yet another edit - christ I've screwed this post up....

In answer to your question
Yes, either use the software they provide (also available from LPRS.co.uk, you must register, but its free) or use the datasheet and type the commands in 'manually' in your favourite terminal program.

Depends on two things:
1. The module waits for a 'two baud byte' delay before sending out the contents of its RX buffer...so really...it just waits for a 'gap' in the transmitted data'..so unless it constantly recieves data (unlikely) then it'll send out what its recieved once its finished recieving.

2. You must pull the RTS line low (pin 7 on the module?), otherwise it will just store all recieved data and not spit out a thing. I suspect that either they have it permenantly low on the board, or its connected to the RS232. Either way, it'll send data out as soon as it recieves it, without storing it up in its 80-byte buffer.

__________________
Inconsistency is the key to flexibility!

 

Not at all. Thanks for you extremely helpful post. I apprectiate it a lot.

I am going to send these units off to active-robots tommorrow and get the other modules in. The MD was kind enough to offer me an exchange via email (even though I obviously took it out of its package).

Thanks very much blueteeth for your useful post and to everyone else for their contribution.

 

i need that codes too pls



-----------------------------------------------
Ücretsiz E-Ticaret Sistemi - www.netfirtina.com

 

You're welcome Ace (always wanted to call someone that)

As with many 'RF' modules, some have 'intelligence' some don't. The intelligent ones are generally the better option, since they do all the RF work, channel coding, PLL settings, handshaking, error detection (sometimes correction too) and provide a nice easy standard interface.

As I said, I have spoken directly to the designer of the easy-radio modules, and boy...he knows his stuff. I'm not on commission for them or anything, but for the price, I don't think you can beat it for a reliable RF telemtry system. Sure, you could do it yourself, for lower datarates (not baud) and high production volumes, its probably best, and sometimes works out just fine, but these little bad-boys do exactly what they're meant to.

And, as always, read the datasheet It will provide all the information you need. I did ask for 'example code' for these, as I was over complicating the design, assuming I needed to do more but...nope...standard RS232, its just like communicating to a PC, only with a delay or two for duplex comms.

Take care, and good luck.

Blueteeth

__________________
Inconsistency is the key to flexibility!