- openocd flashing
  use run_algorithm to hook ROM NVM functions
  see flash/stm32x.c

- add timestamp to received packets 

- transmit callback in the isr

- add a way to set modes: tx_only, rx_only, txrx. (so you can be lazy
  and have blocks of code that don't need to handle rx packets)

- callback for each packet the gets transmitted

- beacon sync

- CCA and ED.