Exercise 02 working: basic screen print out

exercises/02_oled_display/README.md

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+## 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
+```