Actually my project design is custom but i do need the TX/RX part to be able to transmit images for now.
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How to get a strong signal over a long distance
- Thread starter Electro132
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Actually my project design is custom but i do need the TX/RX part to be able to transmit images for now.
Microchip make single chip solutions to allow connection to a LAN for both wireless (does not have your range requirement) and wired. They also provide the libraries for free to set up the connection to the LAN (or act as a server). Using the Microchip LAN hardware and software, you can then use the packaged long distance solution I quoted the link for above to gain the range wirelessly. That removes the need to understand wireless concepts or the relationship between different concepts as you buy the wireless solution to achieve your required distance and speed.
If you pick the right PIC processor, it is really simple as they also provide the full circuit specification and even layouts.
I am no electronic wizard and I have made both the wired and wireless solutions work reliably. They even have some processors with the ethernet hardware on the CPU chip requiring only external magnetics. The magnetics can be achieved by using MagJack rj45 connectors that have the magnetics built in.
If you pick the right PIC processor, it is really simple as they also provide the full circuit specification and even layouts.
I am no electronic wizard and I have made both the wired and wireless solutions work reliably. They even have some processors with the ethernet hardware on the CPU chip requiring only external magnetics. The magnetics can be achieved by using MagJack rj45 connectors that have the magnetics built in.
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What about if i use mobile frequencies to transmit my images or radio satellite communications?
Would it be any different or would they also need protocols? Because i thought all i needed to do was attach a usb stick with one image on it, make sure the right ic type can read it and execute it using a script embedded inside the ic, have that sent off through the mobile frequency using the TX and antenna gain. i didn't think there was any protocols involved.
I'm done - this is a waste of time.
It makes no difference.
It makes no difference
Perhaps you don't understand what a protocol is.
Why don't you explain EXACTLY what you need to do, not how, just what. Adding WHY would also be great.
Well its simple. I would like to transmit an image within a distance of at least 1 km. But for starters, Just having a thought, i actually would just like to start transmitting over a distance of 200 meters and go from there. The only thing the image is supposed to do is get delivered or transmitted.
The amount i would like to experiment on is only 10 kb. The reason is for experimentation and to save money if it is successful. With only 10 kb to transmit, it shouldn't take too long to transfer.
KrisBlueNZ
Sadly passed away in 2015
That makes sense to you, but it doesn't tell us very much at all.
Where is the image stored? What format is it in? Are you using a microprocessor to access it? What do you want to do with it at the other end? Do you have a microprocessor there as well?
And don't just answer those questions. Do a proper job of explaining the whole project.
This thread is already up to post #27 and there have been few signs of it becoming productive.
You need to think, "how would I explain this to someone who doesn't know anything about what I have here, and what I want to do." Because we don't! This information may be obvious to you, but you have to tell us.
Ok cool. I was thinking of how to say it to you guys but just didn't know how to word it out.
So the image (worth 10kb) is stored on a usb and is in jpg format. I'm planning on using an IC which has a script that can read the data on the usb and then execute it sending it through a mobile cell frequency. I'm thinking of adding an antenna that has a TX gain of 6 dbi and RX gain of 3 dbi.
Question: is it possible to calculate the SNR with TX/RX on the same device? I mean if my device is transmitting then it is possible for the signal to come back off the targeted object and have the RX receive it.
The reason for this question is solely for knowing if SNR can be calculated with both TX/RX on the same device.
KrisBlueNZ
Sadly passed away in 2015
You want to transmit on a band that's used for cellular communication? That would be illegal. Or do you want to transmit it through a cellsite? Because that's an option; you can get GSM data modems that accept a SIM card, like a cellphone, and can transmit and receive data on the internet, if they're in a location that has cellular coverage.
You haven't told us anything about the purpose of the project or what you want to do with the image at the other end.
If you have a transmitter and receiver on the same device, the receiver will receive the transmission extremely clearly because there is no loss of signal from the transmitter, so you won't get a meaningful signal-to-noise measurement.
Signal-to-noise measurement at the receiving end is what's important. (And generally, protocols are bidirectional, so both ends are receiving some of the time.)
Assuming you have transmission in both directions, each end can estimate the quality of the link between the two by looking at its own received SNR, because the effects that cause signal degradation will generally cause the same amount of degradation in each direction. So if one end receives a signal at 8 dB SNR, it can assume that its own transmissions will be received by the other end at around that SNR as well. I'm no expert on this; others may be able to elaborate.
You haven't told us anything about the purpose of the project or what you want to do with the image at the other end.
If you have a transmitter and receiver on the same device, the receiver will receive the transmission extremely clearly because there is no loss of signal from the transmitter, so you won't get a meaningful signal-to-noise measurement.
Signal-to-noise measurement at the receiving end is what's important. (And generally, protocols are bidirectional, so both ends are receiving some of the time.)
Assuming you have transmission in both directions, each end can estimate the quality of the link between the two by looking at its own received SNR, because the effects that cause signal degradation will generally cause the same amount of degradation in each direction. So if one end receives a signal at 8 dB SNR, it can assume that its own transmissions will be received by the other end at around that SNR as well. I'm no expert on this; others may be able to elaborate.
What about radar equipment? They have TX/RX on them and use a frequency which, after hitting an object within the radius, bounces back and hits the RX on the same device.
Wouldn't that give a SNR measurement?
Why did I mention SNR? Aaaagh!
So, you have an image on an SD card that you want to put on another SD card about 1km away. And, you want to do that via wireless communications.
Does that explain it?
If so, you need to get yourself a pair of high power nRF24L01+ modules, and find some code to read and write to SD cards.
Get a pair of arduinos (you'll need *at least* an ATMega328, possibly something larger).
You'll also need an external 3.3V regulator as the radio modules need 3.3V at something over 100mA.
Then learn how all this stuff works and write code (perhaps start with plug-compatible lower power nRF24L01 modules as they're chap as chips and if you destroy one or two it doesn't matter)
Once you've figured it all out, see what range you get. Note that you may need a better antenna, you may need to place and orient it correctly, and you may be limited by line-of-sight or something close to it.
Set the speed on the nRF20L01 to the minimum to get maximum range. As you move them further away from each other, if they still work you know the SNR is sufficient.
So, you have an image on an SD card that you want to put on another SD card about 1km away. And, you want to do that via wireless communications.
Does that explain it?
If so, you need to get yourself a pair of high power nRF24L01+ modules, and find some code to read and write to SD cards.
Get a pair of arduinos (you'll need *at least* an ATMega328, possibly something larger).
You'll also need an external 3.3V regulator as the radio modules need 3.3V at something over 100mA.
Then learn how all this stuff works and write code (perhaps start with plug-compatible lower power nRF24L01 modules as they're chap as chips and if you destroy one or two it doesn't matter)
Once you've figured it all out, see what range you get. Note that you may need a better antenna, you may need to place and orient it correctly, and you may be limited by line-of-sight or something close to it.
Set the speed on the nRF20L01 to the minimum to get maximum range. As you move them further away from each other, if they still work you know the SNR is sufficient.
Hey yo, i got the NRF24L01 2.4GHz Wireless Transceiver Module Arduino kit. I'm planning on attaching it to the CH376 USB Communication Module Reader Adapter
(link : http://dx.com/p/ch376-usb-communica...gclid=CN6Kv9Sy6bwCFcFhpQodNEcAkg#.Uw2oqoVj6tM)
with a cable (from 10 pin = transmitter to 16 pin = usb reader). Do you think it will work?
Not without a microcontroller and suitable software (which you must write yourself).
Connecting the USB reader to the transmitter will do nothing (or perhaps even less than that)
Ok that's cool. I'll just get a microcontroller. So when i get this, does it encrypt the file i have in the usb and then sends it out through the transmitter? If it does then that would be great. i'm also thinking of just getting a microcontroller board with memory already placed in but so far having difficulty finding one that's cheap and reliable.
A microcontroller does not do anything out of the box. You program it to do what you want.
Bob
KrisBlueNZ
Sadly passed away in 2015
This guy has been playing us for a long time.
davenn
Moderator
Trolling? Hell no. I think you just misinterpreted what i was saying. What i meant was that if i had software in the mircocontroller which enabled me to read the image file and transmit, would i only need to transmit it through a transmitter for it to send the image?
I assumed that i didn't need to tell you that a microcontroller needed software since Steve had already said that, so i apologise, but i didn't know you needed me to clarify that part. No offense
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