Hello!
Greeting!
We are configuring the TDD Engine based on the X-band radar platform. We found there is a TR_EN measurement probe to test the status of TDD. How to use it? We test this probe and the signal is always the same. Could you give some instructions about how to use it?
Best,
Dongyu
Hi Sam,
Following your suggestion, I do some experiments:
1. Connect P3-13 to P3-15:
2. Connect one of the RF output to the input of a RF detector on the ADAR1000EVAL1Z board. And connect TR probe to an oscilloscope:
3. Since there is no vout pin on the Stingray board which can be directly connected to an oscilloscope, we use the code "detect = sray.LTC2314RFPower" to detect the vout of the RF detector.
4. The vout of RF detector is -54.4817, and the result of TR pin is:
I think that there seems no Tx signal when we using TDD TX engine. The complete code we use is as following:
clear all, close all, clc
%% Array Mapping
%verify element maps correctly to hardware!
subarray = ...
[[1 2 5 6 9 10 13 14];... %subarray 1
[3 4 7 8 11 12 15 16];... %subarray 2
[19 20 23 24 27 28 31 32];... %subarray 3
[17 18 21 22 25 26 29 30]]'; %subarray 4
subarray_ref = [2 4 18 20]; %subarray reference elements
dac_map = [4 3 2 1]; %DAC map to subarray
dac_ref = 4; %DAC reference channel
adc_map = [4 2 1 3]; %ADC map to subarray
adc_ref = 4; %ADC reference channel
%% Config Dev Platform
% uri = 'ip:192.168.1.211';
uri = 'ip:192.168.0.101';
interFreq = 4.5e9; %Tx NCO Frequency & Unfolded Rx NCO Frequency [Hz]
fs_RxTxIQ = 250e6; %IQ Sample Rate [Hz]
periods = 32; %Desired Number Of Periods For Tx Signal
basebandFreq = fs_RxTxIQ/periods; %Baseband Frequency [Hz]
%Setup AD9081 Tx & Rx
tx = adi.AD9081.Tx;
tx.uri = uri;
tx.EnabledChannels = [1 2 3 4];%Enabled Tx Channels, Only Needed for DMA
tx.SamplesPerFrame = 2^12; %Number Of Samples: 4096
tx.NCOEnables = ones(1,4);
tx.MainNCOFrequencies = ones(1,4)*interFreq; %NCO Frequency
tx.MainNCOPhases = zeros(1,4); %NCO Phase
tx.DataSource = 'DMA'; %'DMA' or 'DDS'
tx.EnableCyclicBuffers = 1; %0: Don't Cycle Tx Waveform, 1: Cycle Tx Waveform
%create Tx waveform
A = 2^15*db2mag(-6); %Tx Baseband Amplitude [dBFS]
B = fs_RxTxIQ/2.5;
N = tx.SamplesPerFrame;
T = N/fs_RxTxIQ;
t = linspace(-T/2,T/2,N);
txSig = sinc(B*t);
txSig2 = A*exp(2*-1i*pi*B*t);
%CW Waveform
swv1 = dsp.SineWave(A, basebandFreq);
swv1.ComplexOutput = true;
swv1.SamplesPerFrame = tx.SamplesPerFrame;
swv1.SampleRate = fs_RxTxIQ;
y = swv1();
waveform = ones(tx.SamplesPerFrame,numel(tx.EnabledChannels)).*y;
release(tx)
tx(waveform); %send Tx data
% Setup ADAR1000EVAL1Z in Tx Mode
sray = adi.Stingray;
sray.uri = uri;
sray.Mode(:) = {'Tx'}; %set mode, 'Rx', 'Tx, 'Disabled'
sray.TxAttn(:) = true; %1: Attenuation Off, 0: Attenuation On
sray.TxGain(:) = 127; %127: Highest Gain, 0: Lowest Gain
% sray.TRSwitchEnable(:) = false; %True: SPI control, False: TR Pin GPIO Control
sray(); %Stingray Constructor
sray.LatchTxSettings; %Latch settings to devices
%Setup ADXUD1AEBZ, %Tx Mode
sray.TXRX0 = 1; %0: RX, 1: TX
sray.TXRX1 = 1;
sray.TXRX2 = 1;
sray.TXRX3 = 1;
sray.RxGainMode = 0; %0: Low Gain, 1: High Gain, RX Mode only
sray.PABiasOn(:) = -1.06;
sray.TxPAEnable(:) = true;
sray.TxPowerDown(1) = false; %Enable channel 1 for TX
%% setup TDD
sray.TxRxSwitchControl(:) = {'external'}; %spi: SPI TR Control, external: GPIO TR Control (TR_SOURCE)
sray.FrameLength = 1; %frame length in ms
sray.BurstCount = 0; %number of frames after enable. 0 equals infinite repeat
sray.DMAGateingMode = 3;% 0 - none, 1 - rx_only, 2 - tx_only, 3 - rx_tx
sray.Secondary = false;
sray.TxVCOon = [0 0]; %Stingray/Xud1a TR Frame Start
sray.TxVCOoff = [100e-3 0]; %Stingray/Xud1a TR Frame Stop
sray.TxOn = [0 0] ; %MxFE TX Enable Frame Start
sray.TxOff = [100e-3 0]; %MxFE TX Enable Frame Stop
sray.TxDPon = [0 0] ; %MxFE TX Datapath Frame Start
sray.TxDPoff = [100e-3 0] ; %MxFE TX Datapath Frame Stop
sray.RxOn = [101e-3 0]; %MxFE RX Enable Frame Start
sray.RxOff = [1 0]; %MxFE RX Enable Frame Stop
sray.RxDPon = [101e-3 0] ; %MxFE RX Datapath Frame Start
sray.RxDPoff = [1 0] ; %MxFE RX Datapath Frame Stop
%units are in ms. Settings configure a 1 kHz PRF with 10% duty cycle
sray.EnableMode = 3;% 1 - rx_only, 2 - tx_only, 3 - rx_tx
sray.Enable = 1; %enable TDD Core
detect = sray.LTC2314RFPower; %reads detected power (dBm) for J9 Input
Could you give me some suggestions to figure out this problem? Thanks!
-Dongyu
Hi Sam,
Following your suggestion, I use an Arduino to provide +3.3v. And I use the multimeter to detect the voltage difference between GND pin on the AD9081 and P3-15, which is 3.48V. Since we need to borrow other lab's RF detector, I just test the TR signal this time, the result are as follows:
I think this is the signal generated by the external power, because it doesn't change as I run the "XBDP_TDD_Example.m ". To better test all the channel, I also enable all Tx channels using "sray.TxPowerDown(:) = false". Could you tell me when you can see the rectangle signal? Do I need to setup a stop point when I run the code? My TR signal are always the same.
I think TDD engine synchronously control the AD9081, XUD1A and ADAR1000, right? So, I would like to test the DAC output on the AD9081 board using our normal (non RF) oscilloscope to see whether there is a rectangle wave. Before that, I set the NCO Frequency to 0Hz. Then I found the output signal of DAC is the original sinc signal not the expected rectangle signal after TDD control:
Could you help me check whether my code is correct? I cannot find other reasons about why my TDD engine doesn't work.
Dongyu