User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

433 MHz debugging? (Raspberry-Strogoganoff)

Mon Feb 23, 2015 9:18 pm

I've been having a go at controlling some Maplin remote control wall sockets. I'm doing everything described here:https://github.com/dmcg/raspberry-strogonanoff (on a rev 1 256)

I'm also using the exact transmitter he mentions http://proto-pic.co.uk/434mhz-rf-link-transmitter/

And ... nothing happens :roll: :(

I can see when I run wiringpi gpio readall that gpio 0 is switched to output, so I'm assuming the program is fine (of course its fine)

I'd like to know what the transmitter is up to, but the only recievers I have are the wall sockets (that I know of).
Are there any (Heath Robinson or otherwise) approaches to checking whats happening at 433 MHz to help me try to narrow down the problem?

User avatar
joan
Posts: 14849
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Mon Feb 23, 2015 9:27 pm

piscope will show you what you are transmitting.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Mon Feb 23, 2015 9:37 pm

I've just used that for the first time, just now (its excellent) and I can see the signals from the GPIO but I'm still not convinced the Tx is actually Txing them :?

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Mon Feb 23, 2015 11:05 pm

Hi Morphy,

As you are located in Epping Forest I don't suppose you work in central london? I have a 433MHz receiver / transmitter pair and I know my receiver works with the codes for the maplin sockets. (Getting a transmission out again is where I am struggling). I have a mobile solution for my pi (tablet +wifi router/ usb powerbank) and a spare router/powerbank.

I used Joan's IR hash sample code to detect the 433 MHz signal.
Doug.
Building Management Systems Engineer.

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Tue Feb 24, 2015 10:36 pm

Hi Morphy,

I've just installed the raspberry strogonanoff code and I can confirm that it is working on my B+ with channel 1 device 1.

I've tested a fair sample of the addresses and they all seem to work (sometimes needing the signal repeated), I guess I'll be buying at least one 5 pack.
Doug.
Building Management Systems Engineer.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 9:50 am

Thanks Doug.

I resoldered my transmitter but not had a chance to test it out yet. I'll be really annoyed if I've managed to mess up such a simple 4 wire job.

I'm looking forward to being able to switch on and off (rarely accessed) powered external hard drives as and when needed instead of them being constantly powered up as well as control the convection heater in a nursery room. All sorts of things really.

grahamed
Posts: 277
Joined: Mon Jan 30, 2012 7:01 pm

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 10:42 am

Hi

I find that my FM radio picks up interference form the 433/315 transmitters if they are close. Not accurate but I can hear at least something is being transmitted.

I also have 315 and 433 receivers with a LED on the output - no Tx they flicker randomly, on TX you can see a brief "organised" flash with a brief off period following.

The look at the Audacity method. In fact my Rx's are attached to a £1 sound card with power wires USB to Rx.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 10:48 am

In fact my Rx's are attached to a £1 sound card with power wires USB to Rx.
Oh, that sounds interesting, where did you get that, if you don't mind me asking?

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 10:56 am

My transmitter and receiver pair cost £1.38 the only problem is the shipping time from china (and the risk that it won't arrive at all, but the merchants are usually willing to send a replacement if it does get lost in transit).

I saw a nice pattern from the receiver by using Joans PiScope.
Doug.
Building Management Systems Engineer.

grahamed
Posts: 277
Joined: Mon Jan 30, 2012 7:01 pm

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 12:07 pm

Hi

My £1 USB sound card came from eBay.

Interesting? I think maybe you are reading more than I am saying - I am not making myself clear as usual.

I mean I removed the case from the sound card card and soldered wires to the incoming 5V and zero, and then connected these to bit of strip board with a 4-pin socket for the Rx, an LED, and a couple of resistors to reduce the RX 5V output to mic level with a 3mm5 jack into the sound card, and a pair of pins to connect the 5V data to my £10 logic analyser.

So I can plug into any USB for power and simply observe the LED, or use Audacity (on a Windows PC), or use the logic analyser. In fact I never use Audacity these days but the sound card still provides the power. My first quick check is to listen to the FM receiver.

Convenient yes, interesting not so much.

DavidMS
Posts: 139
Joined: Fri May 25, 2012 8:48 pm
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 12:10 pm

Have you had a look at this thread - I got a Maplin working fine with a bit of work with a picscope http://www.raspberrypi.org/forums/viewt ... 37&t=96688
http://meanderingpi.wordpress.com/
11 Raspberry Pi's and counting....

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 12:14 pm

grahamed wrote:Convenient yes, interesting not so much.
I think you do yourself a disservice. I'm always interested in a bargain and good, useful hacks are also very interesting Well done Sir, three gold stars ;)

grahamed
Posts: 277
Joined: Mon Jan 30, 2012 7:01 pm

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Feb 25, 2015 9:36 pm

you honour me too much.....

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Tue Mar 03, 2015 2:25 pm

Oh dear.
I've just discovered I had the channel number and button number reversed. ie

Code: Select all

sudo ./strogonanoff_sender.py --channel 1 --button 3 --gpio 0 on 
when actually I should have done

Code: Select all

sudo ./strogonanoff_sender.py --channel 3 --button 1 --gpio 0 on 
Well...

I point out this personal humilaition as an information point to the frustrated novice so that they can see that we all make mistakes, dont give up, and when it doesnt work, 99/100 times it's not faulty, it's because you've made a basic error somewhere.

Now I'm going to remotely turn on the kettle and make myself some coffee.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Tue Mar 03, 2015 9:37 pm

...actually no. For some reason it won't work on my rev 1 pi at home. I tested it earlier at work on a new B+ and it worked ok but on an old one its no good.
I've measured the 5v and that seems fine.
Joan's piscope shows a clear signal on the GPIO pin that's being used.

As far as I'm aware the only difference GPIO - wise with rev 1's and later models is with I2C?

Could it be because I'm using powerline Ethernet adapters?

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Mar 04, 2015 12:02 pm

morphy_richards wrote:...actually no. For some reason it won't work on my rev 1 pi at home. I tested it earlier at work on a new B+ and it worked ok but on an old one its no good.
I've measured the 5v and that seems fine.
Joan's piscope shows a clear signal on the GPIO pin that's being used.

As far as I'm aware the only difference GPIO - wise with rev 1's and later models is with I2C?

Could it be because I'm using powerline Ethernet adapters?
I also had it working from a B+, unfortunately I don't fancy fishing out my B from it's current embedded application (too many screws to undo). I might try this at the weekend if you don't find a resolution.
I also use powerline Ethernet adapters.

I don't suppose there's any risk that you might have previously damaged the GPIO that you are trying to use?
Doug.
Building Management Systems Engineer.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Wed Mar 04, 2015 12:33 pm

It is possible the GPIO is damaged. I suppose a simple visual test with an LED can test that.

I have a spare rev2 B at home(with a damaged SD card slot), I'll see if I can bodge a repair and then test again with that.

It makes me a bit sad though as I have emotional attachment to that little original rev 1 B. I like having it working as a central access point / home server.

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Thu Mar 05, 2015 9:28 am

morphy_richards wrote:It is possible the GPIO is damaged. I suppose a simple visual test with an LED can test that.

I have a spare rev2 B at home(with a damaged SD card slot), I'll see if I can bodge a repair and then test again with that.

It makes me a bit sad though as I have emotional attachment to that little original rev 1 B. I like having it working as a central access point / home server.

If it is damaged then just switch the transmitter pin to a different GPIO. (If the Pi is still working otherwise then any GPIO damage is most likely limited to just one or two pins).
Doug.
Building Management Systems Engineer.

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Thu Mar 12, 2015 3:37 pm

Did you get it working yet Morphy?
Doug.
Building Management Systems Engineer.

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Thu Mar 12, 2015 7:35 pm

Not yet, at least not at home but it did work on a different raspi at work.
There's something I've done to that little model B rev 1 thats stopped it but I'm stumped.

I have got a rev 2 with fresh rasbian image. Our DD is turning 1 in a couple of weeks and moving into her own nursery. The baby monitor has just about had it so I'm going to add a temp sensor and composite web cam / mic to that new rev 2.

I am now planning to put the transmitter on this new one too, it can then control a small convection heater in winter and a fan in summer. (and some other stuff around the place, like hard drives downstairs, maybe the dehumidifier too)

I also bought that transmitter reciever pair from eBay you mentioned to play with.

I'm just waiting for time now, things are a tad hectic but in a couple of weeks I should get the chance to spend the whole day on it.

The old rev 1 is still in place doing a fantastic job as download, samba and upnp server, still on the original sd card too!

User avatar
morphy_richards
Posts: 1603
Joined: Mon Mar 05, 2012 3:26 pm
Location: Epping Forest
Contact: Website

Re: 433 MHz debugging? (Raspberry-Strogoganoff)

Sun Mar 15, 2015 8:01 am

I have now got this working on the original rev 1.

I started with a new version of Raspbian on another r-pi and got that working and have just swapped the new card across to the old pi and it worked so I clearly user error somewhere down the line :oops:

Time to rip down the network drives, transfer all popular files to a USB 'passport' HDD, everything else onto chunky big powered external hdds and use the 433MHz relays to power them up when needed.

The newer pi will go upstairs with the second transmitter on another channel with sensors and do environmental control.

Return to “Automation, sensing and robotics”