LCD and buttons
Sentinel has a 20×4 LCD with four touch buttons UP / DOWN / BACK / OK, a buzzer, and an RGB LED. The LCD is always in Indonesian; the Indonesian screen names are given in parentheses below.
Home screen
Section titled “Home screen”The home screen shows the Summary (Ringkasan). UP / DOWN switch to the monitoring pages: Temperature (Suhu), Input, Output, Rules, and Power (Listrik, only if pzem is active). Pages only include active slots, 3 per screen. Text produced by rules appears on the Summary’s bottom line; text longer than 20 characters scrolls.
The Summary’s bottom line prioritizes: identify, alarm, then warnings and rule text (alternating every 3 seconds), maintenance, and normal status.
Buttons
Section titled “Buttons”All four buttons react on touch; there is no hold function.
| Button | Function |
|---|---|
| UP / DOWN | change page (Home, item screens) or move item (menu) |
| OK | at Home opens the menu; in the menu enters an item or runs an action |
| BACK | goes up one level; at Home returns to the Summary. If there is an unsilenced alarm, BACK silences the buzzer first |
The first touch while the backlight is off only turns the screen on. With no touch for lcd_idle_s seconds (default 60; 0 = never returns by itself), the display returns to the Summary.
Menu (press OK at Home)
Section titled “Menu (press OK at Home)”| Menu | Contents |
|---|---|
| Pantau (Monitor) | the same monitoring pages as at Home |
| Jaringan (Network) | IP, gateway, MQTT status and host |
| Device | MAC, firmware version, cfg_ver, label, model, sensors, PCF8574; the 2nd screen shows temperature sensors not yet bound (discovered) |
| Konfigurasi (Configuration) | read only: default temperature limits, warning/alarm limits per temperature slot (W = warning, A = alarm), power alarms, per-input alarms, general alarms, connection, display |
| Aksi (Actions) | Send data now, Identify 10 seconds (buzzer + blue LED, button: identify event to the server) |
Configuration can only be viewed on the LCD; change it through the server, web, or USB serial.
RGB LED
Section titled “RGB LED”| Color | Meaning |
|---|---|
| green | Ethernet and MQTT connected |
| yellow | MQTT down |
| red | Ethernet down |
| blinking blue | identify |
Display settings
Section titled “Display settings”| Key | Default | Function |
|---|---|---|
lcd |
true |
LCD installed (reboot) |
lcd_backlight_s |
120 |
backlight turns off after this many seconds without touch; 0 = always on |
lcd_idle_s |
60 |
return to the Summary after this many seconds without touch; 0 = never |
tz_offset_min |
420 |
time zone of the LCD clock, minutes from UTC (WIB 420, WITA 480, WIT 540) |
buttons_locked |
false |
the Actions item in the LCD menu is disabled (“Tombol terkunci”). Menu, display, page switching, and silencing alarms still work |
exp_addr |
33 (0x21) |
I2C address of the PCF8574 (reboot) |
lcd_addr |
0 |
LCD backpack address; 0 = automatic (reboot) |
label |
empty | location name on the LCD, max. 20 characters |