I'm using two USRP B200 boards to make RF communication between them with SMA cable wired.
And I'm using GNU Radio Companion with DVB-S2 flowgraphs to send&receive some test videos.
Thankfully, these flowgraphs did work.
https://github.com/drmpeg/gr-dvbs2
https://github.com/drmpeg/gr-dvbs2rx
And what I want is to check the error rate of received signal (like displaying "Current error rate: 5%" in the terminal), showing if the signal (video) is well received or not. I tried to find this kind of error rate function in LDPC or any other decoders, but I couldn't.
Or could there be any option to check the error rate between my original video file and received file? Even after all RF communication is done?
I appreciate, many thanks in advance.
Related
I'm working on a BMS project for an electric car. I'm using LTC6804-2 for voltage and temperature measurement in each cells. As a first step of development, I would like to establish a successful communication with the monitoring IC (LTC6804-2). So, I'm sending set config register command and trying to read back the config register values that I have written. If I receive the configuration register values without a CRC error, I consider my communication as successful.
In my case, I do not receive expected register values with proper CRC when I read back. Let me break down my situation into small segments.
I'm working on a custom BMS board for this project(LTC6804-2 and STM32F072). I will attach the schematics below. To test my code, I tested my program with DC1942C demo board and arduino UNO. And it is working fine. I can read back the config register and I can calculate the cell voltage and Auxiliary values.
When I try to implement the same program in my custom BMS board, I'm not getting the correct values. I always get CRC error in the received data.
Following the guidelines from the Analog Devices forum, I tested the Vref2 value after sending the config register command, and the voltage goes up to ~3V as expected. So the IC is receiving the message properly. But Why it is not transmitting back?
Below are the captures from the demo board and BMS custom board.
Register read capture from Arduino Uno and demo board DC1942C
Register read capture from the custom board
In fact I tested the program with STM32 development board and DC1942 demo board, I get the correct values.
Thank you for your help. If you want any additional details, please let me know.
LTC6810-2 datasheet
I'm trying to implement the UPLINK of a Ground Station controlling a small satellite. The idea is that the link should stay always active in between each transmitted telecommand. For this, I need to insert some DUMMY or IDLE sequence bytes such as 0xAA or similar.
I have found that some people already faced a similar issue and posted their questions here:
https://www.ruby-forum.com/t/constant-carrier-digital-transmission/163379
https://lists.gnu.org/archive/html/discuss-gnuradio/2016-08/msg00148.html
So far, the best I could achieve was to modify the EventStream Source block from https://github.com/osh/gr-eventstream in order to preload the vectors with my dummy sequence (i.e. 0xAA) instead of preloading them with zeroes. This is a general overview of the GNURadio graph I'm using:
GNURadio Flowgraph Picture
This solution however introduces a huge latency and the sent message does not appear at the output until a huge amount of time has expired (in the order of several seconds).
Is there a way of programming the USRP using GNURadio so that it constantly sends a fixed sequence which should only be interrupted when an incoming message is passed? I assume that the USRP has the ability of reading tagged streams in order to schedule transmissions. However, I'm not sure how to fit this in my specific application.
Thanks beforehand!
Joa
I believe this could be done using a TCP or UDP source block.
Your control information could be sent to the socket using TCP/UDP. GNU Radio would then collect and transmit the packets. Your master control program would then have to handle the IDLE stuffing but solving the problem external to GNU Radio is easier.
Your master control program would basically do the following:
1. tx control data as needed
2. if no control data ready before next packet must be sent send an IDLE packet
Can anyone please explain how to establish a communication between stm32 dev board and gps module? I am not knowing how to send AT commands to gps module through MC through a source file through UART. Please clarify me in this aspect.
There is a lot of literature on STM32 and UARTs on the web. If I were you I would download the STM32CubeMX. This program generates most of the code for you. You select your processor (or development board), select the clocks and peripherals, and click Generate Code. It also comes with very handy example projects, and might even have a complete project with a working UART that you can put straight onto your board.
And I would first make sure my UART is fully working before connecting the GPS. This you can do by trying to echo. Connect your TX and RX pins with a wire. Then, everything you transmit you will receive as well. It's a easy test to see if everything is working.
I would also work through the TrueStudio IDE. It basically works plug and play
If you use the ublox module, you must use a serial port to communicate.
You have to connect RXD(ublox) to TXD(micro) and TXD(Ublox) to RXD(micro) ,
and config your StmCubemx like This :
http://wiki.sunfounder.cc/index.php?title=Ublox_NEO-6M_GPS_Module
Config Stm32 :
[Step 1: https://i.stack.imgur.com/1B4Ed.jpg ]
[Step 2: https://i.stack.imgur.com/6ULOm.jpg]
[Step 3: https://i.stack.imgur.com/GD0VL.jpg]
If you have another question, please ask
First of all, I think you should test AT command with module sim through (USB to UART) to PC in order to understand procedure operation, such as: module sim - TCP/IP - thingspeak server. The next time, you can refer this link for code: https://bitbucket.org/mbari_peter/sim800-mqtt-ravi/src/78e36076c89b4618cf57a538f0c70f91b2b876dd/modemDrivers.ino?at=master&fileviewer=file-view-default
If you have any questions or encounter any problems, you can ask! Thanks for reading!
Typically, GPS sends data # 1 Hz after starting up. You just need to capture this NMEA sentences and filter the receive buffer according to your requirement.
Try using UART receive interrupt. Make sure the baud rate of both GPS module and STM32 are same.
Hi I am trying to demodulated a GFSK signal using gnu radio
I connected an osmocom source to FIR filter and the filter to Quadrature demod (which output the signal to a file)
as shown here:
my flow graph
the Quadrature demod gain is - samp_rate/(2*pi*deviation/8).
Using Audacity I opened the file containing the demodulated signal. however no matter what packet I send (even if I don't send anything) I don't see the peeks which suppose to stand for a packet.
demodulated signal shown in audacity
you can see hear an example ,it seems that my device is sending packets constantly.
what am i doing wrong?
I think you should change Sample Rate from 4M sps to a value greater than Ch0 Frequency (currently 868M Hz).
I have a GPS circuit board from china. The only information I can find on this thing is :"amoj GPS 04C www.amoj.com"
It has a serial (DB9) connection and I would like to determine how to putty into it or something.
How can I determine what the port settings that are required to access this?
Pictures below:
Photos in Dropbox
The Jupiter TU60 serial interface is 9600 8N1 by default. The only sentence it will output automatically is the flash checksum message about a second after power up. Google the datasheet for the device and it will let you know about this.
To have it output the position and other information, you must command it to do so. There is a default set of commands that are active after power up. They begin with ## and are from the protocol used by Motorola. Refer to the M12+ Users Guide and Supplement (available online) for information on how to use these commands. I have been able to enter them from Realterm. The only tricky part is calculating the checksum. You can use most hex calculators to do that.
According to the datasheet, the unit goes into survey mode automatically and after about 24 hours goes into position hold. The 1PPS and 10KHz signals are valid to less than a microsecond after a few minutes after power up and to 50nS after a day. I have compared this to another standard I have to verify this. You can use the ##Ea command to get the status of the unit and the M12+ Manual will tell you how to decode it.
Look for $GP... messages at 4800 and 9600BPS as yegorich suggest. Common NMEA messages output by GPS devices are $GPGGA, $GPVTG, $GPRMC.. If you find that data coming out, use Google to look up NMEA 0183 sentence structure and you will have what you need...
I have the same board with the Navman jupiter T Tu60 GPS 1pps 10khz GPS Module on it. I just received my sma antenna and have hooked it up. I am using 12.6V power to the centre pin.
It outputs 1pps on the led with no signal, so that is not to be trusted. Mine is labeled 1pps and 10khz underneath the pcb but these are actually swapped! I put the 10KHz output on my dso and get a 10KHz square wave 50% duty cycle signal but there is ringing on the waveform rise so I have to set the trigger level to 0.8v to get the dso to register the 10KHz frequency. I suspect this may be because the output expects a load and is not seeing one. Now, was I using ac or dc coupling?
I too am getting nothing on the serial. I tried 9600, 4800 using putty on com1 (I have a nice old motherboard) and then tried reversing rx and tx but no luck. As of now I am checking out the serial signals with the dso to see if I can work out what is happenning. I suspect that these boards are rubbish, and useful as power supplies only.
It reads 10.0000 on my hp 5328a counter and sometimes reads 9.9999. It would be nice to be able to talk to the gps to see whether it has satellite lock.
Please let me know how you get on and if you find out any further info.
Brett VK6EZ.