[English] Asuro IR communication with a phone

Hello all

Hope you don't mind me asking something in English (my German isn't as good as it should be :)

I'm trying to let my Asuro talk with my Symbian phone (nokia E51) via IR. However the communication isn't going as it should. On the phone I made a quick app to write and read via Serial IR using the default Asuro settings (2400 baud, 8 data bits, 1 stop, no handshake/parity). Reading from the phone gives consistent but wrong data (eg 'A' always appears as a '}', 'T' as a 'W'). Writing from the phone is never received by the Asuro.

When doing the same tests to the serial IR receiver/transmitter I get slightly different results: writing from the phone displays random data on my PC but reading now works as it should.

The communication between the serial IR device and Asuro works perfectly fine btw.

Anybody has an idea on this? (German replies are OK, it's just my German writing being bad). Also I'm a real n00b on robotics, Asuro made me learn soldering ;)

Hi Rick,

welcome to the roboternetz forum!

Did you have a look at the specs of your phone?
I guess it does not use a 36KHz IrDA transmitter/receiver as this is the one used by your Asuro. When the frequencies do not match, you might get back the kind of garbage you described.
As far as i know, the carrier frequency of a cell phone is about 38kHz, which is slightly higher than the one your Asuro uses.

Is it not possible to connect the RS232 IrDA transceiver dongle to your cell phone with a cable. I remember I once had a RS232 cable for my nokia.


Greetings,

O.

Hello,

Thanks you for your reply! :)

A short Google search doesn't reveal much details, the nokia site just says "IrDA (115K)" which doesn't look like useful info.

Would it be possible to change this frequency (preferably on the asuro) via software or is this hardware bound?

I don't know if a RS232 cable exists for my phone (a quick google doesn't reveal anything). Didn't knew such thing existed though, sounds interesting :)

Hi Rick,


it is of course possible, but (the big BUT) you have to write a new bootloader which presets lets say 38KHz as carrier frequency for your newly soldered IrDA module.
Hence you need a ISP programmer, hence your current programmer for RS232 using 36KHz still does not work anymore.


As a 2nd solution you could use a "Daughter Board" where your current IR transmitter and receiver are soldered on. The same you could fabricate for the i.e. 38KHz variant (implies this is really the frequency used by your phone) and this two doughter boards can be plugged to your board somehow.
Now you could flash the Asuro using the "old" components and communication with your phone would go with the "new" board.


In this thread you can see a PCB daughter board as i mentioned above. It is meant for distance detection, but you could use the same principe for your purposes.


What do you think?



Greets,

O.

Hello,

As I'm very new to this many questions are popping up in my head (which board to buy, which parts does it need, how to use the new IR transmitter/receiver etc.). It sure would be an interesting project, but I would need to learn a lot of basics before doing this :)

I also remember seeing some bluetooth board which could replace something else (the cpu?). Maybe I'll look into that if I want an easier solution.

Anyway thanks again for your help.

Hi Rick,

thats the fun of it, building new functionality into the Asuro.

You would need one iso-board (link LÖTPUNKTRASTERPLATTE 811-5 EP 160 x 100 )
and a IR receiver (link TSOP1838)
and an IR sender diode (link diode)

Something like 5euro + p&p.

Whatever, you can try using a ready build up bluetooth board as well. But I am not shure if you can connect to it with a phone.

Greetings,
O.

Alright very nice. This doesn't look too hard :)

Some follow up newb questions (I promise to try to read some beginner electronics sites in the meanwhile ;)):

* I see the board is pretty big, can I just cut it a bit to make it smaller?
* Just to be sure: I need to remove the current IR sender/receiver and plug in the right board whichever I would like to use (36 kHz for flash and other for phone)?

As for the BT option; I hoped it to be more 'standard' but I'd surely need to verify that.

Hi,


yes you are right and of course you can cut off a small part from the big board. Just cut it with a sharp knife and wangle it at the cut area.

Then you;
1) Solder out the IR diode and IR receiver and solder it on the new board
2) Put a connector like this one (link Buchsenleiste)
3) Put a connector like this one she small board (link Stiftleiste)
4) thats it.

You have to cut the "Stiftleiste" and "Buchsenleiste" to lets say 6 pins, the rest you may keep for later use.

For the second daughter board you have to buy sender and receiver as i mentioned in the earlier post. But please try to find out which carrier frequency the phone uses.

Write down how your connector is soldered to keep this in mind for the daughter boards.

i.e.

Code:

---

   
      Stecker
        ------
      1 |o  o| 2   
      3 |o  o| 4
      5 |o  o| 6
        ------

      1 GND
      2 VCC
      3 SFH 5110-36 out
      4 SFH 415-U  Kathode
      5 SFH 415-U  Anode
      6 NC (not connected)

---

Greetings,

O.

Hello

Thanks again your help! However it seems I found a solution atleast for the mobile --> asuro communication: RC5. This does work and from a longer range too (though far less than a regular remote). I'm not sure how to do the Asuro --> Phone communication yet as I haven't figured out how to decode RC5 on a phone, but maybe I could use regular SIR for that and somehow 'fix' the characters on the phone.

Anyway again thanks for your responses. If I'm feeling adventurous I will surely try this anyway.