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university:tools:pluto:controlling_the_transceiver_and_transferring_data [28 Apr 2017 15:50]
Michael Hennerich
university:tools:pluto:controlling_the_transceiver_and_transferring_data [18 Dec 2020 17:55] (current)
Rob Riggs Fix broken link to IIO High Speed doc
Line 13: Line 13:
   * [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​torvalds/​linux.git/​tree/​Documentation/​ABI/​testing | IIO Linux Kernel Documentation sysfs-bus-iio-*]]   * [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​torvalds/​linux.git/​tree/​Documentation/​ABI/​testing | IIO Linux Kernel Documentation sysfs-bus-iio-*]]
   * [[http://​git.kernel.org/?​p=linux/​kernel/​git/​gregkh/​staging.git;​a=tree;​f=drivers/​staging/​iio/​Documentation;​hb=refs/​heads/​staging-next | IIO Documentation]]   * [[http://​git.kernel.org/?​p=linux/​kernel/​git/​gregkh/​staging.git;​a=tree;​f=drivers/​staging/​iio/​Documentation;​hb=refs/​heads/​staging-next | IIO Documentation]]
-  * [[http://events.linuxfoundation.org/​sites/​events/​files/​slides/​iio_high_speed.pdf|IIO High Speed]]+  * [[https://events.static.linuxfound.org/​sites/​events/​files/​slides/​iio_high_speed.pdf|IIO High Speed]]
   * [[http://​ftp.heanet.ie/​mirrors/​fosdem-video/​2015/​devroom-software_defined_radio/​iiosdr.mp4|Video from FOSDEM of how IIO is used in SDR applications]]   * [[http://​ftp.heanet.ie/​mirrors/​fosdem-video/​2015/​devroom-software_defined_radio/​iiosdr.mp4|Video from FOSDEM of how IIO is used in SDR applications]]
   * [[https://​www.youtube.com/​watch?​v=CS9NuRBzN5Y|libiio API introduction presentation video]]   * [[https://​www.youtube.com/​watch?​v=CS9NuRBzN5Y|libiio API introduction presentation video]]
Line 19: Line 19:
 ===== Controlling the transceiver ===== ===== Controlling the transceiver =====
  
 +The code snippet below is a minimalistic example without error checking.
 +It shows how to control the AD936x transceiver via a remote connection.
 +
 +  - Create IIO IP Network context. Instead of ''​ip:​xxx.xxx.xxx.xxx''​ it'll also accept ''​usb:​XX.XX.X''​
 +  - Get the AD936x PHY device structure
 +  - Set the TX LO frequency (see [[resources:​tools-software:​linux-drivers:​iio-transceiver:​ad9361|AD9361 device driver documentation]]) ​
 +  - Set RX baseband rate
 + 
 +\\
 <code c> <code c>
 +#include <​iio.h>​
 +
 int main (int argc, char **argv) int main (int argc, char **argv)
 { {
Line 25: Line 36:
  struct iio_device *phy;  struct iio_device *phy;
  
- ctx =  iio_create_context_from_uri("​ip:​192.168.2.1"​);​+ ctx = iio_create_context_from_uri("​ip:​192.168.2.1"​);​
  
  phy = iio_context_find_device(ctx,​ "​ad9361-phy"​);​  phy = iio_context_find_device(ctx,​ "​ad9361-phy"​);​
Line 32: Line 43:
  iio_device_find_channel(phy,​ "​altvoltage0",​ true),  iio_device_find_channel(phy,​ "​altvoltage0",​ true),
  "​frequency",​  "​frequency",​
- 2400000000);​ + 2400000000); ​/* RX LO frequency 2.4GHz */ 
- +
  iio_channel_attr_write_longlong(  iio_channel_attr_write_longlong(
  iio_device_find_channel(phy,​ "​voltage0",​ false),  iio_device_find_channel(phy,​ "​voltage0",​ false),
  "​sampling_frequency",​  "​sampling_frequency",​
- 50000000);+ 5000000); /* RX baseband rate 5 MSPS */
  
  receive(ctx);​  receive(ctx);​
Line 44: Line 55:
  
  return 0;  return 0;
-}+
 </​code>​ </​code>​
  
 ===== Receiving data ===== ===== Receiving data =====
 +
 +  - Get the RX capture device structure
 +  - Get the IQ input channels
 +  - Enable I and Q channel
 +  - Create the RX buffer
 +  - Fill the buffer ​
 +  - Process samples
 +
 +\\
  
 <code c> <code c>
 +int receive(struct iio_context *ctx)
 +{
 + struct iio_device *dev;
 + struct iio_channel *rx0_i, *rx0_q;
 + struct iio_buffer *rxbuf;
  
 + dev = iio_context_find_device(ctx,​ "​cf-ad9361-lpc"​);​
 +
 + rx0_i = iio_device_find_channel(dev,​ "​voltage0",​ 0);
 + rx0_q = iio_device_find_channel(dev,​ "​voltage1",​ 0);
 +
 + iio_channel_enable(rx0_i);​
 + iio_channel_enable(rx0_q);​
 +
 + rxbuf = iio_device_create_buffer(dev,​ 4096, false);
 + if (!rxbuf) {
 + perror("​Could not create RX buffer"​);​
 + shutdown();​
 + }
 +
 + while (true) {
 + void *p_dat, *p_end, *t_dat;
 + ptrdiff_t p_inc;
 +
 + iio_buffer_refill(rxbuf);​
 +
 + p_inc = iio_buffer_step(rxbuf);​
 + p_end = iio_buffer_end(rxbuf);​
 +
 + for (p_dat = iio_buffer_first(rxbuf,​ rx0_i); p_dat < p_end; p_dat += p_inc, t_dat += p_inc) {
 + const int16_t i = ((int16_t*)p_dat)[0];​ // Real (I)
 + const int16_t q = ((int16_t*)p_dat)[1];​ // Imag (Q)
 +
 + /* Process here */
 +
 + }
 + }
 +
 + iio_buffer_destroy(rxbuf);​
 +
 +}
 </​code>​ </​code>​
  
university/tools/pluto/controlling_the_transceiver_and_transferring_data.1493387419.txt.gz · Last modified: 28 Apr 2017 15:50 by Michael Hennerich