## Exercise 02: OLED Display

This exercise demonstrates multiple OLED rendering patterns on the LilyGO T-Beam Supreme (SH1106).

The firmware runs 3 demos in sequence, then shows a restart banner and repeats forever.

## Demo Sequence

### Demo 1: Scrolling Text
- Shows `Hello #<n>` lines.
- New lines are added below prior lines.
- Up to 5 lines are visible; old lines roll off the top.

### Demo 2: Fill Then Erase
- Displays `Count 1` through `Count 10`.
- Shows a short `Clearing screen...` message.
- Erases the OLED to demonstrate explicit clear behavior.

### Demo 3: Multi-Page Rotation
- Rotates through 3 distinct text pages.
- Each page has different content/layout to demonstrate refresh transitions.
- Includes a changing packet counter field on one page.

### Restart Banner
- Shows `Restarting 3 demos` for 5 seconds.
- Sequence restarts at Demo 1.

## Expected Serial Output
Serial output (115200) prints phase changes, for example:
- `Demo 1/3: scrolling Hello #`
- `Demo 2/3: clear screen after 10`
- `Demo 3/3: three-page rotation`
- `Restarting 3 demos`

### Build
From this directory:

```bash
source /home/jlpoole/rnsenv/bin/activate
pio run -e node_a
```

### Upload
Set your USB port:

```bash
source /home/jlpoole/rnsenv/bin/activate
pio run -e node_a -t upload --upload-port /dev/ttyACM0
```

### Serial Monitor

```bash
screen /dev/ttyACM0 115200
```