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Problem with wireless serial transmisson

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But you're adding extra hardware, slowing things down, and drastically reducing functionality. Manchester routines with a suitable packet size are so much more versatile, and require no extra hardware.

I doubt things need to be that fast, seeing as the baud rates of those modules
are low. Adding extra hardware is a disadvantage, but if it's not mass produced, an extra 2 chips is nothing to write home about.
 
I doubt things need to be that fast, seeing as the baud rates of those modules
are low. Adding extra hardware is a disadvantage, but if it's not mass produced, an extra 2 chips is nothing to write home about.


Two chips is two chips, and personally I'd prefer my radio controlled 'whatever' to respond quickly and have accurate finely controlled speed and manoeuvring. Use the right tool for the job, and the simple remote control chips just aren't the right tool.
 
Two chips is two chips, and personally I'd prefer my radio controlled 'whatever' to respond quickly and have accurate finely controlled speed and manoeuvring. Use the right tool for the job, and the simple remote control chips just aren't the right tool.
That's exactly what they are for, remote control using radio and they are fast enough.
 
Nigel Goodwin as u said now remedy to my problem is.....

1.) To use Manchester coding in program.

2.) Or to use encoder/decoder chips.

3.) Data inverters

Right naa ??

but still not cleared with 3rd one as u trying to say that when the data is transmitted serially it get inverted at the receiver end or something else???

---------------------
Regards
Gaurav Sharma
 
Nigel Goodwin as u said now remedy to my problem is.....

1.) To use Manchester coding in program.

2.) Or to use encoder/decoder chips.

3.) Data inverters

Right naa ??

but still not cleared with 3rd one as u trying to say that when the data is transmitted serially it get inverted at the receiver end or something else???

Yet again, my tutorial explains it - it's because a wireless link is AC coupled, and the serial signal out of the UART must be DC coupled as it is. Using a simple hardware inverter, or doing the serial inverted in software (no hardware UART) removes the DC coupling requirement.
 
Hi Nigel

Me back after my examinations. Sorry for delay in post.

As you talking of data inverter. I find after experimenting that the data pulse out of serial pin in MCU is inverted so I rectified it in programming itself.

Is it ok ?

Thanks in Advance

------------------
Regards
Gaurav Sharma
 
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Hi Nigel

Me back after my examinations. Sorry for delay in post.

As you talking of data inverter. I find after experimenting that the data pulse out of serial pin in MCU is inverted so I rectified it in programming itself.

Inverting it in software is fine, but it means you can't use the hardware UART, as that's fixed polarity, intended for use with a MAX232.
 
OK!! But as i have inverted it in software ....now i have to do Manchester coding ? As I gone through your pic tutorial of license free wireless modules.

Its really a nice explanation. Really appreciate that.
But as I gone through your programs but that is in PIC assemble language. Can you send me sample program(Manchester coding) for At89c51....

As Its new to me so i cant able to take initiative that from where to start Manchester coding software....

Thanks
--------------
Regards
Gaurav Sharma
 
OK !!
Take a look over my schematic. It is wired not wireless as my simulation software(Proteus) don't support wireless simulation.
And I am also having the encoder/decoder description as follow

**broken link removed**

So looking over the channels in schematic and that supported by above IC....the problem can be overcome by using this IC's along with 8051 without using Manchester coding ???

---------------
Regards
Gaurav Sharma
 

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Hi Nigel

I want to ask that can i send a pulse train mean duty cycle(like in order to vary the speed of dc motor) say of 70% using Manchester coding in the program ?

Waiting for reply...

Thanks
--------------
With Regards
Gaurav Sharma
 
Hi Nigel

I want to ask that can i send a pulse train mean duty cycle(like in order to vary the speed of dc motor) say of 70% using Manchester coding in the program ?

You can send whatever digital data you want, if you were sending two byte packets you could use one byte for the speed of one motor, and one byte for the speed of the other.

In my PIC PWM tutorial I use a similar scheme, each byte represents direction (first bit) and speed (other seven bits) - this gives 127 speeds in each direction.
 
But in my program me controlled the speed of motor by making a pulse train of 70% duty cycle using timer and then fed it to the L293D driver when appropriate button is pressed at transmitter unit. Let us suppose we have we want forward direction of motor. Then in this case at IN0 of L293D we have that duty cycle(70%) and at IN1 of L293D we have 0 considering only single motor.

So by combination of IN0 and IN1 the motor doesn't get 100 percent power. As in my case there is 70% duty cycle so only 7/10 percent of total power is fed to motor so its speed is slow.

Now tell me how can I send this complete pulse train in 8 bytes:confused:

-----------------
Regards
Gaurav Sharma
 
But in my program me controlled the speed of motor by making a pulse train of 70% duty cycle using timer and then fed it to the L293D driver when appropriate button is pressed at transmitter unit. Let us suppose we have we want forward direction of motor. Then in this case at IN0 of L293D we have that duty cycle(70%) and at IN1 of L293D we have 0 considering only single motor.

So by combination of IN0 and IN1 the motor doesn't get 100 percent power. As in my case there is 70% duty cycle so only 7/10 percent of total power is fed to motor so its speed is slow.

Now tell me how can I send this complete pulse train in 8 bytes:confused:

You don't, you send a single digital number (one byte) for each motor - this allows you one bit for direction, and seven bits for speed. The receiving microcontroller generates the PWM based on those values.

If all you're wanting is simple radio control, why not just use a standard radio control system and ESC?.
 
Look over the schematic in post #55 this is what I want to control.

oh OK!! I got you...you mean to say I have to make that pulse in receiving microcontroller rather than in transmitting microcontroller. And generate that pulse in receiving microcontroller by single bit from transmitting microcontroller...right ?

-------------
Regards
Gaurav Sharma
 
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