# Doppler Questions

**URL:** <https://forum.dadamachines.com/t/doppler-questions/355>\
**Category:** dadamachines\
**Tags:** doppler\
**Created:** [November 1, 2019, 9:09pm UTC](https://forum.dadamachines.com/t/doppler-questions/355 "2019-11-01T21:09:33Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![iPostHuman](https://forum.dadamachines.com/user_avatar/forum.dadamachines.com/iposthuman/32/115_2.png) [@iPostHuman](https://forum.dadamachines.com/u/iPostHuman)\
**Post date:** [November 1, 2019, 9:09pm UTC](https://forum.dadamachines.com/t/doppler-questions/355/1 "2019-11-01T21:09:33Z")

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Hello,

I was considering buying he _Doppler_ but I have some questions.

- I currently use the **Icestorm** toolchain and am comfortable with it. Do I really need to use the Docker container?
- From what I can tell, it seems the SAMD uses a portion of its Flash for configuring the FPGA via `[PATHTO]/top.bin.h` . I see Arduino code for flashing it. So when the board is power-cycled is the FPGA configured from a “ _special boot_ ” Arduino sketch? I saw this code is the examples:  
`#include "[PATHTO]/top.bin.h" // set up the path to doppler_simple_io or custom firmware`
- So would I need to run a Arduino sketch manually on each power-up?
- The Lattice bitstream size recommended–from the specs–indicates ~833Kb. Does this mean the rest of the SAMD Flash is available for anything else including other bitstreams?
- Is there any other forums or sites catering to the Doppler?

🤔

Cheers.