Send little code via radio 433 mHz.

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Sergejs
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Send little code via radio 433 mHz.

Post by Sergejs »

Hello,

What is the best way send and receive via two MCU some bytes? I have 433 mHz modules. Transmitter FS1000A and receiver RF-5V in one kit. I try use UART but nothing happen. I delete my project and ask you to start from zero point my project. What protocol and communication software need for my project?

chipfryer27
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Re: Send little code via radio 433 mHz.

Post by chipfryer27 »

Hi

I haven't used those modules myself but from what I've read they can be a bit hit-and-miss. Biggest complaint seems to be range with some only managing a few feet even with an antenna (a bit of wire around 170mm should suffice for both Tx and Rx) which perhaps suggests misalignment.

I'd probably be tempted to verify they actually are capable of talking to each other before going further. I might be wrong but I think when a data "1" or a High signal is applied to the Tx input it starts to transmit and the output of the Rx goes "1" or High for as long as the signal is applied to the Tx. Of course that assumes the Rx is in range. If it isn't nothing will appear (remains at "0" or Low). You can therefore verify they "talk" by toggling the Tx input whilst monitoring the Rx output (e.g. push-button on input. LED on output). Once they are confirmed to work you can look at coding.

They are only capable of one-way transmission but you could use it for numerous applications. It could be used to just signal the status of something, or used to remotely switch something. I dare say you could send ASCII messages too via the UART but you would probably need a more complex circuit to comply with ISM rules.

I'd be very wary of applying a constant "1" as that would force the Tx to permanently transmit so the easiest thing would be to have a microcontroller send pulses or use something with a momentary output. At the Rx side you could feed the output directly to an input pin of a microcontroller and monitor for change (watch out for correct voltages, the Rx outputs 5v which could fry a 3.3v chip) having the microcontroller do something depending on pin status.

Hope this helps,

Regards

BenR
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Re: Send little code via radio 433 mHz.

Post by BenR »

Hello,

Have you seen this topic, I beleive I'm using the same modules and have posted example code. It's not the easiest but hopefully not too bad either.

viewtopic.php?f=4&t=1139&hilit=433&start=10

Sergejs
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Re: Send little code via radio 433 mHz.

Post by Sergejs »

What type of radio modules can any recommend for easy use with Flowcode?

chipfryer27
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Re: Send little code via radio 433 mHz.

Post by chipfryer27 »

Hi

Component Library Comms > Networking / Wireless will list BlueTooth / WiFi / Wireless modules that can easily be interfaced using Flowcode, along with E-Blocks.

Modules are available to suit most applications from simple uni-directional signalling to LoRa modems capable of bi-directional communications over many miles, and of course capabilities are reflected in the price! Some will use the UART/RS232 others dedicated pins. It really depends on what you are hoping to do.

Regards

Sergejs
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Re: Send little code via radio 433 mHz.

Post by Sergejs »

I want make little weather station on the street with power from solar panel and get weather out of home via radio. UART or any other protocol it is no so important. I have one weather station yet. But it shows only inside room information.

chipfryer27
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Re: Send little code via radio 433 mHz.

Post by chipfryer27 »

Hi

I think others have posted doing similar. Maybe search this forum and also the "old" forums too as you may get some good pointers.

If the location is within the boundaries of your WiFi then you have quite a few options available. Possibly easier to just send the collected data at regular intervals especially as it will be battery/solar powered, rather than trying to maintain a permanent connection.

If not within WiFi range then you may find it easier to use one of the many ISM "modems" that are available.

How are you planning on collecting / viewing the data? If you posted to ThingSpeak or the like then it is stored for you and you can view it from anywhere using a browser. You could even set up alerts to your phone using PushingBox or the like. Alternatively you could just have a local unit that gets updated and then displays the data, maybe by using a gLCD module or the like.

Regards

Sergejs
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Re: Send little code via radio 433 mHz.

Post by Sergejs »

I will use receiver with MCU and usual LCD 16 x 2 display at home.

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Re: Send little code via radio 433 mHz.

Post by chipfryer27 »

Hi

In that case I'd most likely use ISM modems (I'm assuming another MCU will be gathering the data) as they will more or less give you a transparent link with TTL input/output that can be used with UART/RS232 components. Many different types available depending on range and budget, but it seems especially true with these things that you do get what you pay for.

On the receiver board I'd set up an Interrupt on Rx pin that would simply get the incoming data and put it into a Circular Buffer for processing. That way you are unlikely to miss any incoming data and can process the data at leisure.

Good luck with the project and keep us updated.

Regards

Sergejs
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Re: Send little code via radio 433 mHz.

Post by Sergejs »

I try to send UART by radiowave at ASK modulation mode but receiver do not get anything and screen LCD 16 x 2 is clear.

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