Cellphone remote control, step 1

Following the request described a couple of months ago, I haven't stopped thinking of the cellphone remote control. So, an ATtiny2313 will be the processing unit and to ADC the incoming sound command I will use a tone decoder.

Why not build a software frequency counter? Because it would keep the 2313 running all the time (that's about 99,999% of the time needed) and it would use internal timers that I need to validate the incoming command sequence.

A simple tone decoder is the good old NE567 that I located inside a PSTN answering machine from 90's. The local shop doesn't sell them anymore.

Some more details. The ring tone will be bitonal, so that any ambient noise gets cancelled when the remote cellphone rings. High tone will be used as a carrier, low tone as a signal to the microcontroller. Low tone will be chosen away from flies and mosquitoes sound :-) The ON 001000100010 decoded sequence will have a lower frequency than the OFF command.

Let's warm up the iron!

FT-817 Interactive Frequency Reader - fast dial

One request I got while designing the I.F.R. was to allow a default value for 100/10/1 GHz and 100/10 MHz. This way a frequency can be entered with fewer keypresses.
Like a QSY to 10'368'367'0oo Hz would require to dial in only 8-3-6-7-0-# instead of 1-0-3-6-8-3-6-7-0-#.

This feature can now be (de)activated from the configuration mode, key C. It applies also to normal operations, when the transverter math is not used.

FT-817 Interactive Frequency Reader - PREVIEW video

Here is a 3'33" youtube video showing how the Interactive Frequency Reader works right now.

The firmware shown is taylored for users that use FT-817 in conjunction with a microwave transverter. Please note that not all implemented functions have been shown, the firmware can be extended and it is still subject to changes.

Please leave feedback and, most important, ideas.

Statistiche IAC di gennaio 2011

Guardando il mio log e la classifica mensile inviata da BPU, mi sono chiesto se non possa essere interessante vedere la distribuzione per quadratoni dei partecipanti allo IAC.

Con un paio di operazioni in OpenOffice Calc, ecco un risultato tabellare:

Count - LOC	Banda
LOC	50	144	432	SHF	UHF	Total Result
JN35		2				2
JN44	4	4	3		1	12
JN45	5	15	7	3	10	40
JN52			1			1
JN53	1	7				8
JN54		1	1	1	2	5
JN55	3	2	2			7
JN61			1			1
JN62		1				1
JN65	1	1				2
Total Result	14	33	15	4	13	79

E la rappresentazione grafica:

Traete voi le conclusioni sulla base della vostra banda preferita >30 MHz, ricordando che questi numeri rispecchiano la distribuzione geografica di chi ha inviato i log, non necessariamente dell'effettiva presenza "in aria".

FT-817 Interactive Frequency Reader

... or "detachable display". A first version is currently working on my bench. It is taylored for microwave transverter users, so the current features are:

• configuration mode accessed at frequency reader start-up with parameters in EEPROM
  
• holds baud rate setting
• holds transverter mode on/off
• holds LO+IF and LO-IF math mode
  
• holds frequency update delay in 15 x 100 ms steps
  
• holds two L.O. values down to 100 Hz resolution
• direct microwave frequency dial, with invalid FT-817 frequency control
• mode change
• VFO A/B toggle
• VFO A=B
• RIT on/off
• LO value selection (#1 or #2)
• 15 onboard frequency/mode memories

Since many frequency values can now be entered, keypad digits can no longer work as jolly buttons for other advanced features (a further study on HAM microwave bands is needed, though!). If the transverter mode is OFF, then the frequency reader takes direct VFO value (with valid frequency check; i.e. 156'000'000 Hz will not be sent to the radio because it is out of FT-817 range).

I plan to record a demo video in the next days, so that I can gather readers' feedback before a final public firmware version is packed up and documented.

FT-817 Frequency Reader, present and future

Firmware development has not stopped, and now the frequency reader has a bigger brother: the Interactive Frequency Reader.

Based on the same circuit core (ATmega88/168), it adds the matrix keypad to the external display readout.

Most of the recent work has been towards enabling the I.F.R. to accept direct microwave frequency dial and QSY the FT-817 to the proper frequency, according to the selected L.O. value.

Meanwhile I am completing the Frequency Reader documentation, so that it will be up on the website soon. The stand-alone display firmware is now stable and ready for the general public.

Heat up your soldering irons!

FT817 Interactive Frequency Reader: weights...

I have assembled a circuit of the work-in-progress "Interactive Frequency Reader" and weighted it: about 90 grams without the CAT cable to the FT-817.

This weight includes the circuitry, the 16x2 LCD and the 4x4 matrix keyboard.

Must not forget to add the enclosure weight too!

The assembled circuit confirms that the hardware design has reached a stable version, as well as basic firmware functions. Now I have to think of a user friendly, menu driven?, interface.

Macro for cameraphone from viewfinder lens

I have come across an article on Hack a Day about building and adding a macro lens to a cameraphone at almost no cost. It requires a lens from the laser head of a DVD reader, and according to published pictures and tutorials, we are talking about a very small part.

While looking inside the 35mm camera (see previous post), I gained access to some lenses and ... guess what? There's one that can be used as a macro extension for a cameraphone!

It is the viewfinder lens, the one where the photographer was looking into before the digital camera era. It is larger than the DVD laser head, so it is easier to handle and mount on an adapter (to be constructed).

This addition works by reducing the minimum distance at which the camera can focus, so that you can get closer to the subject and in fact capture more details.

Let's see how my 3.2 Mp F2.8 auto focus cameraphone behaved when holding the macro lens in front of it.

The sample was a 2 €cent coin at sunset, that you can see here side by side to the lens:

(picture shot without the macro lens, obviously)

Let's hold the lens in front of the camera and get an interesting detail (click on pictures to see them 1:1):


Or, zooming in at full resolution on the focused area:


If I had shot at the same distance but without the macro lens, this would have been the result:


As last, with and without the macro lens side by side:


Now I have to figure out a way to hold the lens in front of the camera.