> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oryx.mechatronstudio.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Connect the device
> Linking an ESP32 generator over USB, sending it the signal and controlling it.
The app can send the signal you have open to an **ESP32 generator** and play it
on its outputs.
The link is **point to point**: everything happens between your computer and the
device. There is no server in between, no account, and nothing goes out to the
internet.
## Requirements
| What | Detail |
| -------- | ------------------------------------------------------------------------- |
| Board | A classic ESP32 (WROOM / DevKit v1) |
| Firmware | The Oryx Signal sketch, flashed once. See [Firmware](/en/device/firmware) |
| Cable | The same one you flash the sketch with |
| Browser | Chrome, Edge, Opera or Firefox |
**Safari cannot talk to the serial port**, so there the option is not offered. If
your browser does not support it, the app says so: *"This browser cannot talk to
the serial port."*
## Connecting
Over USB, with the usual cable.
The browser shows the list of ports and you pick the board's.
The app introduces itself and keeps retrying until the device finishes
booting and answers.
There is no network to switch and no address to find out.
Opening the port **resets the board** on almost every development module,
because the USB converter uses those same lines for auto-boot. The app does not
fight it: it keeps trying until the device answers.
### If something fails
| Message | What to check |
| ------------------------------------------ | --------------------------------------------------------------------- |
| *No port was selected* | The browser dialog was cancelled |
| *The port could not be opened…* | The Arduino IDE serial monitor is open and holding the port: close it |
| *The device did not answer* | The board does not have the Oryx Signal firmware |
| *The device runs another firmware version* | Reflash it with the sketch that ships with this version of the app |
| *The link with the device was lost* | The cable came loose or the board reset |
## Sending the signal
The device plays back **from its own memory**: first you send it the whole
signal and only then tell it to start. Once loaded, it keeps playing even while
you edit something else on screen.
The panel shows a summary —*"3 channels · 240 steps"*— and the send status:
| Status | What it means |
| --------------------------------------------- | ---------------------------------------- |
| **Nothing sent yet** | The device is empty |
| **Sending…** | The signal is on its way |
| **The signal is on the device** | What is inside is what you see on screen |
| **The signal changed since it was last sent** | You edited something: send it again |
What comes out of the device is exactly what you drew, including the analog
curves with their rounding.
### Adjustment notices
If what you see on screen does not fit into the device as is, the app tells you
before sending:
| Notice | What happened |
| -------------------------------------------------------------------------------------------------------------- | ----------------------------------------- |
| *The device has N outputs for this mode: the extra channels are not sent* | There are more channels than pins |
| *The signal is empty: there is nothing to play* | Nothing is drawn |
| *The signal does not fit in the device memory at the requested resolution: it is sent with N samples per step* | The resolution was lowered to make it fit |
## Controlling playback
| Button | What it does |
| ------------------------------ | ------------------------------------------------- |
| **Start signal** | Starts playback |
| **Stop signal** | Stops it |
| **Restart from the beginning** | Goes back to the start and zeroes the lap counter |
## Live parameters
In **analog**, it is the amplitude of what the DAC puts out, between 0 and
3.3 V.
In **digital**, a pin swings between 0 and 3.3 V and knows nothing of
intermediate levels. There this value goes out as a **reference voltage** for
the external stage —divider, buffer or level shifter— that sets the real pulse
height.
Without that external stage, in digital the pins always output 3.3 V and the
voltage setting changes nothing.
How long each step of the signal lasts, in microseconds.
At **0**, the step time rules.
Above **0**, one full pass of the signal is one engine revolution:
```
step time (µs) = 60 000 000 / (rpm × total steps)
```
This is what turns a CKP signal into an engine speed sweep.
Changing the step time or the cycles **restarts the pass in progress**, so the
change shows on the oscilloscope right away. The lap counter is not zeroed: that
is what *Restart* is for.
## If the cable comes loose
The signal stops on its own and the outputs go low. It is on purpose: the device
cannot find out that you closed the tab, so if it goes a while without receiving
anything it treats the link as finished.
Connect again and resend the signal to carry on.
## Board outputs
| Mode | Where it comes out |
| ----------- | -------------------------------------------------------------------------- |
| **Digital** | GPIO 16, 17, 18, 19, 21, 22, 23, 13 — one pin per channel, in editor order |
| **Analog** | GPIO 25 (DAC1) and GPIO 26 (DAC2) — up to two channels |
In digital, the voltage value comes out on **GPIO 25** as a steady reference
voltage.