Aust supplier for Hope RF modules

[moxhamj]

I see Microzed are soon going to be stocking the Hope modules. http://www.microzed.com.au/Rf433.htm

I had a play with these and they have real potential. One big advantage is that what goes in one end comes out the other end. With raw RF modules, when they are talking in=out, but when the transmitter is off, the receiver is getting noise. So then you need to filter the noise somehow, usually with a front end picaxe. Using the Hope modules, the data is clean enough to run into a uart.

Also, another advantage is the antenna screws in. With raw modules, you need to measure a bit of wire and get it right to the nearest milimetre. Not hugely hard, but a proper antenna does look neater too.

I got 200 metres out of those modules on a range test. But manuka wanted his samples back so I wasn't able to put them into the project I was building.

Microzed are quick suppliers too - order it and it arrives the next day by express post!

 

[Grant Fleming]

Not a bad price either.
I have ordered many items from Microzed and always received them the next day.

 

[manuka]

Guilty as charged- I twisted MicroZed's arm to take on the HopeRF agency, & have supported them both with an enthusiastic intro. article for the Oct. "Silicon Chip". Such largesse on my part has been thirsty work ! I'm now pondering a swag of 4 in a mesh network (jargon for "pass it on to the correct owner"). Dr_A - that pair continues to do A1 further loan work,presently under the whims of Andrew "BrightSparK" in New Plymouth. Stan

Extra: These little HopeRF tx/rx darlings certainly are impressive! For the impatient & curious I'll upload my pre-tweaked draft (which features at least 6 mistakes) to => www.picaxe.orconhosting.net.nz/hoperf1.pdf
( European readers with delicate sensibilities should excuse the article's colonial vernacular)

 

[D n T]

Stan, is this heaven on a chip?

Stan, I saw it, read it, ordered it.
Small observation and question, You have an electrolytic capacitor on your module but there is no mention of it on the data sheet or your parchment.
what value is it?
Stan, your have a breadboard, a PICAXE, a wireless module with a flash aerial and views of the ocean, apart from a chilled beverage, what else is there?

 

[manuka]

DnT- what else is there indeed! This initial setup was just intended to alert folks to the devices of course, & -judging by "selling like hot cakes" feedback from MicroZed- the darlings are certainly cutting the mustard.

ELECTROLYTIC??? No electro. was used in this initial trial, so guess the view is blinding you. In case you pondered where the PICAXE had gone, "Molly" the cat is eyeing up the config breadboard ( which needs no PICAXE of course).

NB The initial draft had circuitry blunders- the correct Tx/RX & config. layout is shown below. N.B. You don't even need the extra tx/rx LEDs I've shown ( although these are handy to verify PICAXE action),as it turned out (undocumented) that the Hope modules have tiny SMD LEDs already embedded on their boards. I'd not noticed them until live testing developed. Stan

 

[D n T]

To see or not to see, that is the question

Stan, I had a look at the article again and on the picture under the title there appears to be an electrlytic capacitor on each of the actual radio modules, not on the breadboard. When I checked the hoperf datasheet their diagrams don't show this capacitor, I thought you might have added it or does it come built on the module when you purchase it. Mine have not arrived yet to check. I am bracing myself for the arrival as I type. Hark to the sound of the Valkyries, or is that just the clapped out posty bike coming over the hill!!!

 

[Hooter]

Each module has the cap included on the PCB.
Hooter

 

[moxhamj]

D n T - are you referring to the pictures of the Hope modules? If so, yes it looks like an electro on the module, but then further down is a photo of a different module with what looks like a surface mount. These are how the modules are made. I suspect an electro on one and a surface mount tantalum on the other.

Some of the hope modules are higher powered than others. Maybe the extra cap is there on the higher power ones. Look at the photo on page 3 of Stan's article - are there two holes there for an extra component?

Anyway it probably doesn't matter. These modules come pre built and work straight out of the box. And great news that they are selling well.

 

[D n T]

Those caps

My modules are herre and I have got them working. They came with an electrolytic soldered in place, although these are not shown on the data sheet, you get that on the big jobs.

They work really well!!!!

Stan check your private messages, please.

 

[moxhamj]

D n T - I'd very much appreciate it if you could find a few moments to do some range tests. I got 200 metres through trees with them 1.5 metres off the ground. I reckon they can go further though.

Blimey Stan, Microzed owe you a beer. Type in "Microzed" into Google and the third hit is "Microzed offer Hope Microelectronics"

I just ordered a HR010 dual module kit from Microzed.

 

[manuka]

DnT/Dr_A: Glad the little darlings are behaving OK. 200m thru' light bush was about my finding too, but simple ~6dB gain ( thus range doubling) 433MHz "cotanga" Yagis each end should boost this x2 x2, giving ~1km. Yes- the draft article had diverse wiring errors (not my fault, as they arose during initial SC type setting), which hopefully will be corrected pre publication.The pix I've attached above are correct.

SC have an admirable editorial policy of sending back to the author (pre publication) a .pdf draft for such tweaking, & it certainly helps catch typos & wiring blunders. It's no doubt part of their success story. Given today's resources, I wish other publications woiuld do this- so many still have a closed shop on their articles, meaning errors galore can then creep in. I was phone interviewed by a nameless US publication a few years back, & in spite of insisting that I "see" what they would publish, this "just couldn't be considered due to our editorial policy". Predictably - especially given US/NZ accent issues- the final article featured diverse "Oh no" blunders.

NB- following occasional problems with "floating" logic, I've now recommend linking the HM-TR pin 6 directly to +ve during normal RX/TX operation. This pin allows module sleep if tied low of course.

 

[D n T]

Purring PICAXE range

I thought I might go for a drive the other day down a paticularly straight road. I threw my mate out with the transmitter in one hand and a beverage in the other and drove off. With line of sight maintained I stopped and put the breadboard on the boot and it still purred, it would not shut up.
By the way I was 3.3 and a bit kilometres away.

HOW COOL IS THAT!!!
I went back and picked my mate up.

Also I had the students do range tests around the school:
400 metres line of sight
350 metres through a tilt-a-wall concrete walls 200mm thick
Although it did breakup at 200 metres through a wall and security mesh.

I want more of them, lots more.

Now I need to start sending 5 or 6 ADC readings at a time (I want a beasty remote control). So I think I will have to use 29 or 30 "85"s and then drop in my variables. If this (or when this) works I will have to send a beverage across the creek.
I have to get back to it. purrrrrrr

 

[moxhamj]

Sweeeet.

My modules are being rushed to me as we speak.

You may not need so many 85s. Even 12 is probably overkill. I've found it more useful to use less 85s, but drop in a checksum word at the end and then reject packets that don't add to the checksum. It is useful to have "range picaxe" that is receiving a packet once every few seconds, and flashes once for a packet received, and twice for a packet received with a valid checksum.

All credit to Manuka too for the upcoming Silicon Chip article. As always, Stan has the knack of taking a complex problem and explaining it in an easy to understand fashion.

 

[D n T]

Transmission about transmissions

I just thought that the onboard module had a buffer of 32 byte buffer and I had to fill it up before it would transmit, oh well you get that, I haven't had a play yet. Must play.

All hail MANUKA The MAN U KAn!!!

 

[manuka]

Are those "Australian distances" or the regular metric ones? Just kidding- I'm also seriously impressed!

My 2nd article is slanted at tx/rx data work & of course the old PICAXE serin hangup blues immediately raise their head. What I envisage are tx units sending "I am here" beacon pulses every few seconds-minutes, & remote rx. responding with a return transponder style tx chirp if it receives such a probe signal. Mmm- but what if BOTH sets get caught in a receiving mode, meaning thus neither end will be able to break out & give a yell. Listening, listening ... Each expects the other to call first, & thus nothing happens- it's worse than a teenage crush.

HopeRF have informed of an HM-TR RSSI test point in fact, but I'm pondering a more direct PICAXABLE approach. We've all scratched out heads over this before, & I recall a wired workaround arose, but how about the following wireless hack.

This involves charging a cap via an suitable initial "111111" style preamble (ASCII "?" perhaps) from the receiver output, & then sensing this accumulated "1" via a PICAXE pin read or readadc. At this High/1 stage the serin routine can THEN be dropped to, allowing (perhaps with further tweaked qualifiers for timing also in the received string) the data itself to be read. Meanwhile the cap. charge can be bleed away with a suitable resistor, resetting the system for further serin hangup free looping. Abracadabra - it's more "serin select" rather than timeout, but looks workable! Comments welcome. Breadboarding in daylight- weary night eyes ...

 

[Grant Fleming]

I have two units arriving tomorrow - so, that's the day's previously planned work out the window then!

 

[D n T]

More transmissions

They are all METRIC distances, metres not meters, accurate to... about that.
Grant, I'm pleased to see you have your priorities are correct, good to see.

With regard to duplex comms and the teenage crush problem. What if you set up the link with one unit controlling the duplex timing, like the girl.
The girl is a default transmitter
The boy is the default reciever.
The girl transmits then becomes a reciever for a set period, eg ~100ms or so.
The boy recieves the information then pauses for ~10ms then transmits.
After the transmission the boy returns to reciever mode.
Once the girl recieves the information pauses for ~10ms then transmits again.
If the girl doesn't have anything to transmit perhaps it would send a "ping" to ensure a connection and the Boy could then repeat the pause then trasmission protocol.

Just a thought.
I wish relationships ran according to a standard protocol, but thats an entirely different topic for another strand on another forum.

Later.

 

[moxhamj]

D n T - I'm presuming by now you have seen how the 32 byte thing works - you send 32 bytes and it sends them on. Or if you send a lesser number, it sends the smaller packet on after a small delay. Very tidy!

Re serin hangs - well they can drive you a bit crazy. The more devices you have, the more complex hangs you can get till the whole network hangs.

I am wondering about two picaxes per board. One can do transmission - one receiving. The transmit one can send a transmit pulse every few minutes as you say - so no hangs there.

BUT - this is the bit I have spent a long time pondering. The receiving picaxe might get its packet, but how does it then transmit this data to the transmitting picaxe (that is sitting right next to it)? You can't use serout/serin - I am pretty much convinced of that - otherwise there is another opportunity for a hang. There are other protocols though. Two wires - one data and one a clock. Or the one I am using, which is to send the bytes as pulsouts of 1.5ms for a high and 0.75ms for a low. I posted the code on another thread recently but can post again if you think this is worth pursuing.

At a fundamental level, this works because it can time out.

Serin/Serout still works best for RF comms though.

 

[moxhamj]

I do like dealing with Microzed. Modules arrived this am. Can also answer the capacitor question from earlier - it is a 220uF 10V electro. Now I can do some more range tests.

 

[centrex]

I have my modules up and running, I tried them at 2400 baud at first but found them a bit unreliable.
Changed to 300 baud as per Manuka's article and they now perform very well, I will try upping the speed in stages to see what I get.
I know the article was an early version but I read that the modules were set up at 2400 baud but the PURRTX code said 300 baud.
I would be most interested to know others are running the devices at.
One small problem I have with one of the modules is that the red led does not work, the module is ok just no led.
Would like to hear more of what people are doing with their modules.
Regards
Centrex

 

[D n T]

Up to $50.00 in petrol doing range testing and still need help

I thought I might do an extreme range test that might rival the Wellington harbour test. I have a large bay near my house and it is 7.32 Kms (acording to the GPS) across LOS. I still have this constant PURRING NOISE
VERY SWEEEET!!!!

Now I have to set up a fool proof program to transmit my variables. I need to send up to 6 bytes ( 6 variables ). I want to use Hippies code as a start I would like to know if instead of peeking and poking the values, can I just substiute in the variable and change the max data lengthto 6 or should I poke the variables instead of the ASCII OKAY that is used. I'm off to try it so let me know.

 

[centrex]

Hi DnT
Most interested to know what post the Hippy code is that you mention in your post.
I have had no luck when using a (qualifier) at the end of the string of 85's.
The devices are transmitting and receiving and I can get the data of the receiver.
I like you have a need to transmit and receive some remote data ( solar array).

 

[moxhamj]

Purring will always go further than data, but the ultimate aim of this is sending data. I tend to quote my range tests in terms of a packet going through with a valid checksum.

I'm not sure of the optimum number of 85s but they don't cost much to send. Somewhere between 4 and 12.

Then a 2-3 letter header. Eg "ABC"

Then the data bytes. Limited by the number of b registers, so max is 14. I am using less - 9 in fact.

Then a word at the end. I simply take all the other bytes and add them up, and send this sum as the checksum. So if you use two bytes for the checksum word, the maximum number of data bytes is now 12.

Then set up one picaxe, eg an 08M to send these packets once a second. And the receiving picaxe flashes a led if a packet comes through and the checksum adds up. Then you can do some more range tests - hopefully using less than $50 in petrol this time!

 

[centrex]

I have the modules talking not just ' purring' at last.

purrtx:
b1 =72
b2=117
b3=108
b4=108
b5=111
serout 2,n300,(85,85,85,85,85,"TW",b1,b2,b3,b4,b5)
pause 500
goto purrtx


The receiver quite happily prints "Hullo" on the computer in terminal mode.
The 85's and the"TW" is what Gill uses at the Backshed.

Range from one end of the house to the other, to wet to go wandering around the streets.

 

[moxhamj]

Keep us posted, we are all eagerly awaiting results!