DT5215 firmware emulator

A DT5215 control API on localhost. It answers every endpoint of spec/dt5215-api.yaml with plausible, consistent data, so the SDKs of all seven languages — and your own program — can be tested with no instrument in the loop.

pip install dt5215-emulator
dt5215-emulator --port 8080

curl -s -X POST http://127.0.0.1:8080/api-v1.0/login \
  -H 'Content-Type: application/json' -d '{"username":"user","password":"user"}'

from dt5215_emulator import Emulator
import dt5215

with Emulator() as emu:                       # a free port
    with dt5215.connect(emu.url, username="user", password="user") as dev:
        print(dev.info().hostname)            # dt5215-emu

What it reproduces on purpose

Three behaviours of the real firmware that a client has to get right, and that a hand-written mock usually gets wrong:

• a refusal is HTTP 200 with result: false, not a 4xx;
• /reboot and /restart_app answer nothing and drop the connection;
• a bearer token is required everywhere except /login and /alive, and /alive reports whether the token it was given is valid (so a client can tell "instrument down" from "token expired").

It is also stateful: switching HV off changes what the next /get_hv_status says, disabling a chain empties it, writing a register reads back, an enumeration walks its phases (in about a second, not minutes), and a board firmware upgrade progresses board by board.

Driving it from a test

Emulator(state=...) takes a prepared State, and every field of it can be changed while the emulator runs:

from dt5215_emulator import Emulator, State

state = State()
state.chains[0].los = True              # a chain with loss of signal
state.client["control"] = True          # Janus attached: a board upgrade must be refused
with Emulator(state=state) as emu:
    ...

Options

Default users: user/user and caen/caen.

What it is not

It does not pretend to be the instrument's data path: there is no event streaming, no FPGA, no real timing. It answers the control API, and that is all the SDK needs.