domingo, 10 de julio de 2011

Modify 1,2GHz A/V receiver for FPV


I bought this Kit Wireless 700mW from Securitycamera2000 , This kit is used for CCTV and also for FPV,although only 4 channels, my idea is to modify it to expand the frequency transmission and reception.
Original Channels:
1 1080MHZ
2 1120MHZ
3 1160MHZ
4 1200MHZ


I started to modify the circuit of the receiver,the main board contains the video amplifier, the audio demodulator and the microcontroller to control the PLL inside tuner module.

This module is as found in the old analog satellite receivers,the PLL is the TA1322FN chip, also contains down converter circuit is very similar in programming the SP5055,in my tuner the address selection pin is grounded.


Details pins for tuner module

Controller core is the PIC16F628A, a 16x2 display and 4 buttons for setting.



FEATURES
 900MHz to 1300MHz frequency
 Step 250KHz, 1MHz, 5MHz and 10MHz (Up Date 20/02/2012)
 Supports up to 8 pre-set frequencies
 Button lock mode
 Automatic shutdown of the display backlight after 10 seconds
 4 adjustment button:
 Button up: frequency up
 Button down: frequency down
 Step button: short touch = change step / touch along = locks
 Memory button: short touch=call preset channels/ long=records in memory / lock mode =unlocking three hits


Hex file and schematic  available  here 
Any questions or comments please do not hesitate to contact to the email josuezb81@gmail.com , I can also customize the text on the second line display and the frequency range.


if you believe that the information provided is useful and can help you, please consider making a donation that will allow me to continue with projects like this.
Visit my blog about DATV in spanish.






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21 comentarios:

  1. How to apply and hex code modified to
    FM frequency 88 - 108 Mhz.
    Thanks.

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  2. Hello Harisa,sorry for delay,to control the pll chip in the commercial FM band is necessary to develop a new control program for the pic.

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  3. Would you be able to post a pinout of the tuner module, as well as which pins from the lcd module go to where? And did you have to un-ground the address selection pin?

    I got mine in the mail today, and though the tuner module is slightly different, the pins seem to be in the same location.
    Mine says Samsung TBLU18120IN1T, but I can't seem to find any additional information on it. If you could help, that would be great!

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  4. Hello Legot; open your tuner module and see what the PLL chip, just so you'll know if the program can control, the hex and schematic diagram is available here,upload pins details.

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  5. Thank you,
    On mine the PLL is a TD7626, here is the datasheet. http://pdf1.alldatasheet.com/datasheet-pdf/view/32347/TOSHIBA/TD7626F.html

    Once I looked at that datasheet (I didn't find it before because the chip was marked strangely) I was able to identify the pins I needed to use, so that's all cleared up.

    One Question left, my address selection pin isn't tied to anything, will this be a problem?

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    Respuestas
    1. Hi, Legot,apparently both pll chips are compatible, the program as this is for the MA1 and MA0 grounded direction, you should ground the pin 10 in its TD7626F,I think if it worked,please tell how it went, Greetings.
      Americo8888

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  6. My comtech module have an SP5055, does the address selection pin (10) should it be grounded too ?
    thanks

    Cedric

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    Respuestas
    1. Hi Gladus, yes, the address selection pin in your Comtech module should be grounded, the hex is 100% compatible with SP5055.

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  7. Great, thanks for your help,now I can make my lawmate (upgraded saw filter) compatible with 910 and 980 MHz !
    Another thing, about LCD, I was thinking that it wasn't working, until I found that a 10K potentiometer was needed to adjust the contrast (external pin are VSS/VDD and center pin E0/contrast adjustment on LCD).
    I will post a link on RCGROUP for helping other guys like me making a lawmate VRx mod.

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    Respuestas
    1. Hi Gladus,We share what we can do,if is correct the Pin 3 of the LCD display must be connected to trimpot 5k, plot it out of my Proteus simulation software is therefore not indicated,thank you for sharing with other boys.
      Americo8888

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  8. I make a thread on rcgroup for applying your mod to a lawmate VRx, here : http://www.rcgroups.com/forums/showthread.php?t=1660167

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    Respuestas
    1. Gladus, it's great that this modification is also useful for Lawmate VRx, thank you for the link, in the coming days I will upload the pcb to be reproduced more easily.

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  9. Hello, dear Americo8888, my tuner has a PLL SP5655, just direct linking,

    I see also that the frequency of division varies for PLL to PLL, it influences the frequency of step? ex. some are 1/64 1/128 other 1/512 1/1024,
    You can me help
    Congratulation for the work

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    Respuestas
    1. Hi Ricardo, of course, the prescaler modulus directly influences the minimum step frequency variation of the PLL, low prescaler values ​​allow large steps and low phase noise, high values ​​of the prescaler allow small steps but increases the pll's phase noise.
      Thanks.

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  10. My tuner has a PLL SP5655, just direct linking

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  11. Hello americo my name is juan arteaga I am of venezuela, and am doing the same his work try to modify the wireless equipments bada of 4 channels in 2.4ghz. I try to place the pic 16f628 with the software nigel goodwin but I have failed until hour go 2 weeks and something in this.Good work his my friend

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    Respuestas
    1. Hola Juan, como verás, aquí también hablamos y escribimos en español,je,je,je, yo soy de Perú, habría que ver cual es el chip PLL que esta en tu Kit inalámbrico de 2,4GHz, tal vez sea el TSA5520, no estoy seguro, pero en todo caso es fácil hacerle un "hacking" para utilizarlo en toda la banda y más.Saludos

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  12. saludos,73 americo te escribi en el correo electronico pero ni modo amigo ..si tienes razon se me durmio la mosca no te dige el pll es el lmx2330 he visto el datasheet tengo ubicado las dos patas de control 11 ,clock,12 data ,y creo no estoy seguro hay que hecer una programacion en el pll ,via rs232 hay un programa" codeloader 4s" penso que es para selecionar los bit hacia el pll, y asi programar el futuro controlador pudiendo ser el 16f628 tengo un display con un pic 16f628 que me la frecuencia de 2.3000 ghz hasta 2.500ghz todo esto es de un programa para modificar el "wavecom.jr" y su pll sp5055 ...es de tener en cuenta que mi receptor y transmisor tienen 4 canales y el cristal del pic es 4mhz pic que no tiene nombre ... hice un osilador de 4mhz para variar el clock lo logre 4.050 mhz y asi salir de el margen de las wifi que aqui es un mar de interferencia en los 4 canales 1) 2.411ghz 3)2.431ghz 3)2.451ghz 4)2.471 ghz ,que me aconsejas que puedo hacer para tener un vfo efectivo .saludos y 73 cordiales

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  13. Excellent work! Does it really help tune the signal?

    Question - do you think its safe to extend the cables from the receiver to the amplifier? Like a meter of wire?

    Thanks!

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    Respuestas
    1. Hi Daniel; the maximum capacity of the buses for the i2c protocol is 400pF, that limits the maximum communication distance of a few meters, I believe that a distance of one meter between the micro-controller and the tuner will not be problem.

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    2. Thank you! I'll definitely try this out.

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