As I have bought two ask modules (tx and rx) operated at 434 MHz.. **broken link removed** **broken link removed**
And I want to make remote control robot for that i am using two AT89C51 and using serial transmission. The motors are running properly when I attach TXD and RXD through wire simply. But when I introduced this module the circuit is not at all responding I felt that if there is no connection b/w two 89C51 they are operating on their own. As i am checking the circuit on breadboard first...
So please help me out......unable to achieve wireless transmission
The serial pin provides output suitable for RS232, it the same signal, just needs converting (and inverting) to RS232 levels by a MAX232 or similar.
You might try putting a hardware inverter between the modules and the processors, this may give you some results, but you really need Manchester coding, and not to use the hardware UART's.
As I am firstly making the circuit on breadboard....
It is not a standard RS232 connector.... TXD pin simply transmit the data serially for ex. 1010
and RXD pin on other side receive that data serially as 1010 which is transmitted
and it is TTL logic and there is not any use of any voltage level converters like max232.....
As I am firstly making the circuit on breadboard....
It is not a standard RS232 connector.... TXD pin simply transmit the data serially for ex. 1010
and RXD pin on other side receive that data serially as 1010 which is transmitted
and it is TTL logic and there is not any use of any voltage level converters like max232.....
whether the 89C51 is bought with software loaded or you have locally programmed? generally 89C51 can be programmed only using HV programmer and not ISP programmer. if you were trying to use ISP type, you need to change to 89S51(2).
I have programmed it..both transmitter and receiver IC's.
And I am also having Atmel 89 series programmer used for burning the program.
It supports almost all types of Atmel 8051 type mcu....so it supports AT89C51 too.
As I've already told you, it won't - a wireless link is AC coupled, not DC coupled.
Your easiest option is to try a hardware inverter at either end, a simple transistor and two resistors is all you need - this may make it work reasonably.
I presume you are using a decently slow baud rate?.
I actually got a device just like this one, with a single on/off channel running at something like 433 mhz. It was on a really good sale so I threw it in when I bought my junebug, have to pay shipping either way. I haven't messed with it yet, but I was thinking baud rate would be a concern. My first guess would be that with a 433hz transmitter/reciever you might be limited to half that for the baud rate. But again, thats just my first guess, I havent gotten into it yet.
As I've already told you, it won't - a wireless link is AC coupled, not DC coupled.
Your easiest option is to try a hardware inverter at either end, a simple transistor and two resistors is all you need - this may make it work reasonably.
I presume you are using a decently slow baud rate?.
Depending on the modules they may not work at 9600, but 1200 or 2400 should be fine - but (AGAIN!) they won't work like that - my tutorial explains why.
What do you want to do? If you just want to send a few commands to a robot, then
you can use the HT12E and HT12D with your modules. That way you only need to deal with parallel data.
What do you want to do? If you just want to send a few commands to a robot, then
you can use the HT12E and HT12D with your modules. That way you only need to deal with parallel data.
But actually I want to control Two DC motors and also want to control the speed of DC motor that I think can be done with the help of micro controller only.
But I not understand that RF modules work fine with HT12E and HT12D. Then what is problem with AT89C51??