mangavalkandClaude Opus 5.5
6e4d5e152b
Nano / driver: - No full on/off flip at boot; the first display() after boot is a forced full redraw instead, since the physical dot state is unknown - Send READY when booted ESP32: - relayOn() only switches and waits when the relay was off, and waits for the Nano's READY (3 s timeout) instead of a fixed 3 s on every frame - relayOff() ends Serial and releases the TX pin so the idle-high line no longer back-powers the Nano through its RX pin - No display commands are sent while the relay is off - Switching the relay on cancels a pending power-off countdown Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
3.3 KiB
Arduino Nano: flipdot driver
PlatformIO environment: nano
The Nano is connected directly to the Brose panel electronics. It keeps an 84 × 19 frame buffer and takes drawing commands over serial (115200 baud). It has no clock or network logic.
Behaviour
- Boot: the Nano loads the flip time from EEPROM, sets up the pins and sends
READY. It doesn't flip any dots at boot. The relay powers the Nano, so it boots every time the display is switched on. - First
display()after boot redraws every dot, because the Nano doesn't know which state the dots were left in. display(): compares the new buffer with the last one that was shown and strobes only the dots that changed.- Every 2 minutes (
REFRESH_TIME) it does a full redraw to fix dots that got stuck. A full redraw blocks for about half a second, which is long enough to overflow the 64-byte serial buffer. So it only runs right after aD(the end of a frame, when the ESP is quiet) or when no serial data has arrived for 2 seconds. - Flip pulse length (µs, 50–2000) is set with the
Tcommand and stored in EEPROM, so it is kept after a reboot. The default is 200 µs.
Debug options
Uncomment these at the top of main.cpp:
| Define | Effect |
|---|---|
DEBUG |
Print unknown command bytes on the serial port |
MEASURE_REFRESH |
At boot, time a full redraw and print the duration in ms |
Serial protocol
Each command is one ASCII line that ends with \n (\r is ignored). The Nano
collects a whole line before it runs the command. If a line is broken or unknown, it is
skipped and the next line starts clean. Coordinates are 2-digit hex. Color is 0
(black) or 1 (yellow). The ESP32 driver (ESPSERIAL) only uses s, S, F, D and
T.
| Cmd | Format | Meaning |
|---|---|---|
s |
sXXYYc |
Set pixel in the buffer |
S |
SXXYYc |
Set pixel and flip it right away (direct mode) |
F |
Fc |
Fill the whole buffer |
D |
D |
Push the buffer to the display (changed dots only) |
P |
PXXYYcsTEXT |
Print text at (XX,YY), color c, size s. A literal \n (backslash, n) in TEXT starts a new line. The whole line can be at most 64 characters. |
B |
BXXYYWWHHcHEX... |
Draw a bitmap. WW must be a multiple of 4. Pixel data is one hex digit per 4 pixels, row by row. The data is drawn while it arrives, so it is not limited to 64 characters. |
R |
R |
Print the buffer as ASCII art on the serial port |
T |
Tnnn |
Set the flip pulse length in µs (decimal, 50–2000), stored in EEPROM |
Replies on the Nano's TX pin:
READYafter booting. The ESP waits for it before sending the first frame.ERR: ...for invalid commands.
Example (what the ESP32 sends for one pixel and a refresh):
s0a051
D
Wiring (default pinout)
The pins are defined in lib/BROSE9323/BROSE9323.h.
If you use the PLCC adapter board, build with -D FLIPDOT_PLCC_ADAPTER to switch to its
pinout.
| Signal | Nano pin |
|---|---|
| ENABLE | D7 |
| ADDR_0 / 1 / 2 (panel select) | D3 / D5 / D6 |
| COL_DATA | D4 |
| COL_0 … COL_4 | D8, D10, D9, D11, D12 |
| ROW_0 … ROW_4 | A3, A4, A2, A0, A1 |
| ROW_RESET | D13 |
| ROW_SET | A5 |
| Serial RX | D0 (from ESP32 TX) |