Running AX25 example on Raspberry Pi 2

[Godtec]

Hi there:

After installing luaradio twice and re-compiling liquid-Dsp twice. I cannot seem to get the luaradio example to run. Below is the error I am running into. Any help is very much appreciated!!

---

mikek@raspberrypi:~/luaradio $ ./luaradio examples/rtlsdr_ax25.lua Usage: examples/rtlsdr_ax25.lua mikek@raspberrypi:~/luaradio $ ./luaradio examples/rtlsdr_ax25.lua 144.390e6 Found Rafael Micro R820T tuner Exact sample rate is: 1000000.026491 Hz Using Volk machine: neon_hardfp_orc Using Volk machine: neon_hardfp_orc [FrequencyTranslatorBlock] Downstream block LowpassFilterBlock terminated unexpectedly. [FrequencyTranslatorBlock] Block runtime error: ./radio/core/pipe.lua:300: write(): Broken pipe stack traceback: [C]: in function 'error' ./radio/core/pipe.lua:300: in function 'write' ./radio/core/block.lua:387: in function 'run' ./radio/core/composite.lua:558: in function <./radio/core/composite.lua:558> [C]: in function 'xpcall' ./radio/core/composite.lua:558: in function 'start' ./radio/core/composite.lua:452: in function 'run' examples/rtlsdr_ax25.lua:44: in main chunk [C]: in function 'dofile' ./luaradio:105: in main chunk [C]: at 0x0000c790 [RtlSdrSource] Downstream block FrequencyTranslatorBlock terminated unexpectedly. [RtlSdrSource] Block runtime error: ./radio/core/pipe.lua:300: write(): Broken pipe stack traceback: [C]: in function 'error' ./radio/core/pipe.lua:300: in function 'write' ./radio/blocks/sources/rtlsdr.lua:210: in function <./radio/blocks/sources/rtlsdr.lua:198> [C]: in function 'rtlsdr_read_async' ./radio/blocks/sources/rtlsdr.lua:228: in function 'run' ./radio/core/composite.lua:558: in function <./radio/core/composite.lua:558> [C]: in function 'xpcall' ./radio/core/composite.lua:558: in function 'start' ./radio/core/composite.lua:452: in function 'run' examples/rtlsdr_ax25.lua:44: in main chunk [C]: in function 'dofile' ./luaradio:105: in main chunk [C]: at 0x0000c790 mikek@raspberrypi:~/luaradio $

MikeK

[vsergeev]

Hi Mike,

Are you running this in a graphical environment? It looks like a plotting sink might be crashing.

In general, the RPi2 can't keep up with the signal processing at the 1 MHz sample rate used in many of the examples. They will run on the RPi3, which is much more performant than the RPi2.

You could try modifying this example to run at one lower sample rates in the 200 - 300 kHz range, as this example really doesn't need the 1 MHz bandwidth. For example, at 250 kHz:

...
local tune_offset = -50e3
local baudrate = 1200

-- Blocks
local source = radio.RtlSdrSource(frequency + tune_offset, 250000)
local tuner = radio.TunerBlock(tune_offset, 12e3, 20)
...

[vsergeev]

Closing for now. Feel free to reopen if the issue resurfaces.