I've had a HackRF on my wishlist ever since discovering Mike's awesome SDR video series. That said, I wouldn't want to dedicate the device to the meter reading

I've had a HackRF on my wishlist ever since discovering Mike's awesome SDR video series. That said, I wouldn't want to dedicate the device to the meter reading (hence my trying to pare down to the bare essentials). Funny you mention using multiple dongles, I've actually been doing just that while working out the protocol to capture as many messages as possible. Except in my case, since 2.4MHz gets me exactly 6 channels, I can just run multiple instances of my application, each looking at their own 2.4MHz chunk of spectrum. No need to truly synchronize them.