Need a quick start for DORJI

johndk

Senior Member
I just purchased a pair of DORJI DRF443D20I 433MHz radios. Being somewhat impatient to get them up and running, I'm wondering if anyone has experience with these modules. Or better yet, has some sample code I can play with. I'd like to run them using hserin/out with a 28x2 and a 20M2 (which could become an X2 if necessary).

I tried just a basic connection with hsersetup matching the default parameters.
 

johndk

Senior Member
Thanks for the reference. I hadn't found that in my search. It looks like a bit of code and discussion to get me started in the right direction. Once I digest it, I might have a question or two.

John
 

SAborn

Senior Member
You don't need all the data Westy pointed you to.
First we need to know what model package you have ... DRF4432D20I-M1, or DRF4432D20I-M2, or DRF4432D20I-L1/L2

See this PDF to help with what module you have.
 

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johndk

Senior Member
I've got the L1 package and started playing. I expected the worst having read some of the cautions and intricacies on wireless coms. Well, was I surprised!!!! They just work! I hooked them up with hser... , threw data at them, and that was it. I did learn a couple of things in the process. 1) they only like ascii (no raw bytes), 2) for whatever reason the first byte of the transmission needs to be a $0 (as in hserout 0, ($0,"some data"). Maybe another byte value would work as well. Haven't tried.

I haven't been able to get them to respond to 'setup' yet, however. But that's no big deal for now. The default settings work fine.

So I didn't need a 'quick start'. Already playing. But that's not to say I wouldn't love some feedback from anyone who's already done something serious with them.

I must say that I'm impressed by the module's ease of use, so far. But I'm not impressed by Dorji's documentation.
 

SAborn

Senior Member
Do you have the setup tool from Dorji, if so then setup should be very simple.

As for the first byte needing to be $0 that is not needed, it should except any data sent, so it may be a fault in the setup.

The setup tool looks like this.

Dorji setup.JPG

The serial parameters need to be set to the baud of the picaxe on both wireless modules, then the RF parameters need to be set to a faster baud then the serial baud, this is because the RF needs to transmit the data faster then the serial data is received to the module, or the FIFO buffer will be filled and missed data will occur.

Example .. serial 4800 baud and RF 9600 baud.

The "Net ID" and the "Node ID" need to match in both wireless modules or they will not talk to each other.

Also the "Channel" needs to match in both modules.

All very simple to setup using the setup tool.

To put the modules into setup you do require the Dorji USB adaptor and place a jumper across the 2 header pins marked "set"

Also with the L1 module you can connect it direct to the picaxe programming port (serial out) (with additional 5V) and simply use Sertxd to send data as you would if sending data out to the computer screen, this is how I use these modules.
 

johndk

Senior Member
No, I don't have the Dorji setup tool. I was trying to use the picaxe to do the setup via the hserout port. I didn't get that to work. Hadn't thought of using the programming ports. I'll try that next. Thanks for the tip.

John
 

johndk

Senior Member
So much for my optimism. I suddenly can't get the units to communicate. They send and receive just fine. But it is almost like the baud rates aren't matched and I get garbage at the receiving end. So I tried to access setup as suggested by SAborn. No luck. I tried via the processor and hserout/in. Also no luck with either unit. So I can't see what the setting are, although as far as I know I didn't change them from factory defaults.

I checked the documentation many times to make sure I had all the proper connections made for chip setup and am now at wits end. I even tried operating without the antennas thinking that the units might be too close sitting sided by side on my desk. Nope. They work (or don't) just the same. I've checked to make sure I'm sending only ascii characters, as that seemed to be a problem at first. I tried with and without the leading $00 character which seemed to make a difference yesterday.

Any suggestions or tips would be most appreciated. Dorji's software won't work with my picaxe cable. Does anyone know where to purchase one of their USB adapters?
 

grim_reaper

Senior Member
You need to have the transmitter and receiver much further apart - they shouldn't be sitting next to each other, antennas or not!
 

SAborn

Senior Member
I think the Dorji modules come shipped at 9600 baud standard, so try running the picaxe at 9600 baud for your data.

Without the setup tool it is hard to change this but with the tool its very easy.

As for the usb adapter to suit your module you need the Dorji "DAC13" usb adapter to suit your module you have, which can be found here.

http://www.dorji.com/pro/kits/demokits2.html

You can buy direct from Dorji, although the shipping might be a little high for a single item, still worth contacting them.
 

johndk

Senior Member
I think the Dorji modules come shipped at 9600 baud standard, so try running the picaxe at 9600 baud for your data.
Yes, these do come preset at 9600 both for RF and for SER. I checked many times to make sure I was setting my hsersetup to the right baud rate. I'm running the 28x2 at 8MHz and using B9600_8 as the baud constant.

Is there any place but dorji where I can get the DAC13? Their tool is tailored for this module and won't work with the USB download cable for the Picaxe. I was really hoping I could communicate via the chip coms as the documentation states is possible. I get no response, even using SAborn's suggestion.

I considered the possibility that the picaxe baud rate doesn't match the Dorji baud rate. That could explain the lack of response during setup. But it's negated by the fact that the transmit module is definitely receiving the characters I send and transmitting them. And the receiver is receiving the correct number of characters, but not what was fed to the transmitter.

Is it possible that I'm overloading the receiver by having them so close? I would think that if the receiver were overloaded, it would not function at all. But the blue receive LED blinks at the right times and the right number of characters are received.
 

TheBackShed

New member
Did you have any luck with these John?

I bought a pair a couple weeks back, set both up on USB-Serial adapters, and they seam to be communicating, but its not making sense. If I type ABC on module 1, I get Ph( on module 2. If I type ABC on module 2, I get Ph( on module 1.

If I type Ph( on either, I get }{y on the other.

Return on on gives Ca on the other.

I dont get it. They are default settings, waiting on a DAC13 board ( Thanks Pete ) to change settings, but dont think that will help.

In the manual ( or lack of ) it does say to short the Setup pin to ground, and try AA FA commands, but got no response.

Any help appreciated. I bought these two modules to provide telemetry between a rover and PC.

Glenn
 

papaof2

Senior Member
Can you change:
speed
parity
number of bits/character (7/8)
etc.

Regardless of the hardware, it looks/sounds like those type mismatches in wired serial communications.
Some of the wireless comm protocols do show their great-grandparents in some of their operation. Might not apply to the Dorji modules but it's a potential path of trouble shooting.
 
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