API System Configuration

picocalc.sysconfig exists only for apps whose app.json declares the "sysconfig" requirement (otherwise it is nil). get("wifi_pass") always returns nil — the WiFi password is write-only through this API (set works). Note that /system/config.json itself is readable by a root-filesystem app through picocalc.fs.

System-wide configuration stored at /system/config.json on the SD card. This is distinct from per-app configuration (picocalc.config). System configuration persists across all apps and reboots.

picocalc.sysconfig

Functions

picocalc.sysconfig.get(key)

Get a system configuration value by key.

• Parameters:
  • key (string): Configuration key name
• Returns: (string or nil) The value associated with the key, or nil if the key does not exist

local ssid = picocalc.sysconfig.get("wifi_ssid")
if ssid then
    picocalc.repl.print("WiFi SSID: " .. ssid)
end

---

picocalc.sysconfig.set(key [, value])

Set a system configuration value. Pass nil as the value (or omit it) to delete the key.

• Parameters:
  • key (string): Configuration key name
  • value (string or nil, optional): Value to set, or nil to delete the key
• Returns: None

picocalc.sysconfig.set("brightness", "80")
picocalc.sysconfig.set("old_key")  -- deletes "old_key"

---

picocalc.sysconfig.load()

Reload the configuration from /system/config.json on the SD card, discarding any unsaved in-memory changes.

• Parameters: None
• Returns: (boolean) true if the file was loaded successfully

if picocalc.sysconfig.load() then
    picocalc.repl.print("Config reloaded")
end

---

picocalc.sysconfig.save()

Write the current in-memory configuration to /system/config.json on the SD card.

• Parameters: None
• Returns: (boolean) true if the file was written successfully

picocalc.sysconfig.set("timezone", "America/New_York")
picocalc.sysconfig.save()

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Well-Known Keys

Key	Description
"wifi_ssid"	WiFi network name for auto-connect on boot
"wifi_pass"	WiFi password
"brightness"	Display brightness level
"tz_offset"	Clock offset from UTC in minutes (may be negative)
"dim_timeout_s"	Idle screen-dim timeout in seconds; "0" disables dimming (default 60)
"battery_pct"	"1" shows the battery percentage inside the header’s battery icon instead of a fill bar (system menu → Settings → Battery %)