http://dangerousprototypes.com/docs/Bus_Pirate

picocom -b 115200  /dev/ttyUSB1

• From http://dangerousprototypes.com/docs/Bus_Pirate#Firmware_upgrades: https://github.com/mikebdp2/Bus_Pirate/tree/master/package_latest/BPv3
• Upgrade instructions: https://github.com/BusPirate/Bus_Pirate/tree/master/package/BPv3-firmware (opt2 seems best https://github.com/BusPirate/Bus_Pirate/issues/7#issuecomment-248265311)
• pirate-loader: https://github.com/BusPirate/Bus_Pirate/tree/master/package/BPv3-firmware/pirate-loader-source

HiZ>i
Bus Pirate v3b
Firmware v5.10 (r559)  Bootloader v4.4
DEVID:0x0447 REVID:0x3043 (24FJ64GA002 B5)
http://dangerousprototypes.com
HiZ> $

The following is only valid for a bootloader v4+, otherwise an update is needed http://dangerousprototypes.com/docs/Bus_Pirate_v3_bootloader_upgrades

$ ./pirate-loader_lnx --dev=/dev/ttyUSB1 --hex=/home/shtrom/src/mikebdp2_Bus_Pirate/package_latest/BPv3/bpv3_fw7.0_opt2_18092016.hex  
[...]
Writing page 41 row 335, a780...OK
Erasing page 42, a800...ERROR [50]

The error is expected https://github.com/BusPirate/Bus_Pirate/issues/7#issuecomment-248103673

Reset the BP by unplugging it.

HiZ>i
Bus Pirate v3.b
Community Firmware v7.0 - goo.gl/gCzQnW [HiZ UART I2C SPI] Bootloader v4.4
DEVID:0x0447 REVID:0x3043 (24FJ64GA002 B5)
http://dangerousprototypes.com

Success!