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connect 433 MHz RF Transceiver with microcontroler ATmega8535 — Parallax Forums

connect 433 MHz RF Transceiver with microcontroler ATmega8535

mikomiko Posts: 8
edited 2011-10-20 06:24 in Accessories
sorry, Ihave problem
how to connect 433 MHz RF Transceiver with microcontoler ATmega8535
give me program with C how to setting 433 MHz RF Transceiver as transmitter and receiver

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2011-03-27 18:47
    We cannot give you a C program for the 433 MHz RF Transceiver. You'll have to write that yourself. There are links on the webstore page for the transceiver's documentation and some examples in Parallax Basic (here). Page 3 of the documentation shows the pin connections. At a minimum, you will need Vdd, Vss, and two logic signals, the bidirectional data line and Transmit / Receive. As the documentation suggests, it's best to put out a short (maybe 3ms) sync pulse. The data itself can be any format that's meaningful for you. Typically, the data line is connected to some kind of UART in the microcontroller. This has to be a bidirectional signal so the UART transmitter has to be turned off in order to receive.
  • micro_engineermicro_engineer Posts: 7
    edited 2011-04-15 11:11
    Pick up a copy of the LINX data sheet for specific information.

    I wrote code in C for a PIC microcontroller that will allow bidirectional use with my own protocol & CRC-8 error checking. However it was not portable directly to the ATMega family.
  • mikomiko Posts: 8
    edited 2011-04-17 21:21
    how to sync the rtransmitter and reciever, give me the algoritm
  • mikomiko Posts: 8
    edited 2011-04-17 21:31
    micro_engineer wrote: »
    Pick up a copy of the LINX data sheet for specific information.

    I wrote code in C for a PIC microcontroller that will allow bidirectional use with my own protocol & CRC-8 error checking. However it was not portable directly to the ATMega family.
    you can give me that code
    I use two chip microcontroller ATmega8535
    the first chip control two data ADC by delay 5 second and contro the transmitter
    the second chip control the receiver and interfacing with computer
  • micro_engineermicro_engineer Posts: 7
    edited 2011-04-18 11:26
    Again, you must pick up & read the LINX datasheet in order to understand it. However, getting it working is easy. Getting it to work reliably is harder.

    "Syncing" in this case refers to simply initially writing some dummy values to establish a read-to-transmit state for the transmitter(s).

    This is done with the example code in the manual provided by Parallax, by setting the output data line high for a while. I sent two bytes of 0xFF instead.

    I would be happy to send you the information I have (PM me) but please do not demand it from forum posters. (You will get a much better response by asking politely, thank you).

    Regards.
  • mikomiko Posts: 8
    edited 2011-05-04 19:06
    I,m sorry Mr. Mike Green. The current of power suplly is not necessarily exactly 10 mA, I have a 50 mA current. 50 mA is sufficient or excess
  • Mike GreenMike Green Posts: 23,101
    edited 2011-05-04 21:21
    The documentation says that the power supply current needed is approximately 10mA with this dropping to approximately 4mA in standby mode. I'm sure this varies somewhat with supply voltage with the current needed lower at 3.3V than at 5V. As long as your power supply can provide at least this amount, you should be fine.
  • mikomiko Posts: 8
    edited 2011-05-05 00:44
    I only ensure. Whether with 50 mA .It's OK
  • mikomiko Posts: 8
    edited 2011-08-04 03:21
    What will happen if the wireless sending data with frequency of 433 MHz, the frequency of data same with frequency of tranceiver.
    thanks
  • Mike GreenMike Green Posts: 23,101
    edited 2011-08-04 09:25
    As I mentioned in the reply to your PM, you can't do that. The Transceiver is designed to transmit low frequency information, less than 10KHz. Under noisy conditions, it does better limiting the frequency to perhaps 2400Hz. It's possible to design transceivers that can handle higher frequencies. For example, you can buy or build transceivers for 433MHz that can handle video up to 6MHz. If you want to handle data at higher speeds, you need to design the transceiver for that use. As the transmitted data rate gets closer to the carrier frequency, it becomes more and more difficult and complex (and expensive) to reliably transmit (and receive) the data. Study telephone modems for examples since these transmit data at high rates over communications channels with limited frequency response.
  • ScharkalvinScharkalvin Posts: 1
    edited 2011-08-21 07:19
    There are many good program examples app notes for the serial, spi and i2c (twi) interfaces on the Atmel site. One of these could be adapted to interface with your 432mhz transceiver.
  • mikomiko Posts: 8
    edited 2011-08-22 21:53
    What the type of modulation abaout this tranceiver, ASK, FSK or other modulation...?
  • FranklinFranklin Posts: 4,747
    edited 2011-08-23 11:04
    What the type of modulation abaout this tranceiver, ASK, FSK or other modulation...?
    Have you checked the documentation? Please do.
  • mikomiko Posts: 8
    edited 2011-10-20 02:35
    how much voltage (range of voltage) that can be transmitted by wireless....?
  • LeonLeon Posts: 7,620
    edited 2011-10-20 03:35
    As much as you wish, just send it as a sequence of bytes.
  • Mike GreenMike Green Posts: 23,101
    edited 2011-10-20 06:24
    You have complete control and complete responsibility for what gets transmitted over the RF link. The examples show the use of asynchronous serial I/O, but you could use Morse code if you wanted ... pretty much any kind of on/off signaling. The transceivers are designed for bit rates on the order of 2400/sec, but there's a fairly wide range where it will work. Any numeric value (like a voltage) can be sent as a sequence of 8-bit bytes, whether as a binary number or as a sequence of characters that represent the number in decimal, hexadecimal, or whatever.
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