Starting from fresh Raspian SD card, cannot upload firmware to Atmel device

Started out with a fresh Raspian SD card, no open energy monitor software installed at all.

Used these instructions: Part 1/3: PlatformIO open-source embedded development ecosystem - Blog | OpenEnergyMonitor which worked, but when I run the script, it hangs here:

Checking program size
text       data     bss     dec     hex filename
17502       152     896   18550    4876 .pioenvs/emonpi/firmware.elf
Building .pioenvs/emonpi/firmware.hex
Configuring upload protocol...
AVAILABLE: arduino
CURRENT: upload_protocol = arduino
Looking for upload port...
Use manually specified: /dev/ttyAMA0
Uploading .pioenvs/emonpi/firmware.hex ⇐ hangs here

I’m missing something. Anybody have any thoughts?