V5.0.5-airspy dump1090-fa with native AirSpy support now available

[LawrenceHill]

@gtj0

Please try different sample rates and formats!

Also remember the native reference frequencies of the Airspy Mini (24MHz) and the R2 (20MHz).
See these posts:

Airspy Mini - New investment?

In the case of the Mini, the reference frequency is 24 MHz. To get 12MSPS, it’s a simple binary counter, but for 20MSPS, a whole PLL is run at a few hundreds of MHz, followed by many clock dividers. This adds noise and adds a few milliamps of current drain. The data throughput is also something to consider. More data means everything runs at a higher speed: ADC, DMA, USB transceiver, interrupts, etc. This all translates in more current and a higher thermal envelope.

Airspy Mini - New investment?

Same story. The ref clock in the R2 is 20 MHz, which means 20 MSPS is native and doesn’t require any extra PLL. To get any rate that is not an integer division of 20 MHz, (for eg. 24MSPS,) a PLL + dividers are required. Furthermore, an extra effort is required for packing all the data at 24MSPS to fit within the transfer budget of USB 2.0. The MCU is clocked to allow these configs to run smoothly if the host computer is fast enough, but again… more data => more current => higher temperature.