RPi Pins: Check available devices.

rpipins/__main__.py

@@ -1,4 +1,6 @@
 #!/bin/env python3
+import os
+import stat
 import re
 import subprocess
 import sys
@@ -73,12 +75,22 @@
     RIGHT_PINS[n] += [""] * NUM_DEBUG_COLS
 
 
-def get_current_pin_states():
-    if hasattr(gpiod, "chip"):
-        chip = gpiod.chip("/dev/gpiochip4")
+def get_gpio_char_device():
+    for num in (4, 0):
+        try:
+            if stat.S_ISCHR(os.stat(f"/dev/gpiochip{num}").st_mode):
+                return f"/dev/gpiochip{num}"
+        except FileNotFoundError:
+            continue
+    return None
+
+
+def get_current_pin_states(device):
+    if hasattr(gpiod, "chip") and device is not None:
+        chip = gpiod.chip(device)
         gpio_user = [line.consumer for line in gpiod.line_iter(chip) if line.offset < NUM_PINS]
-    elif hasattr(gpiod, "Chip"):
-        chip = gpiod.Chip("/dev/gpiochip4")
+    elif hasattr(gpiod, "Chip") and device is not None:
+        chip = gpiod.Chip(device)
         gpio_user = [line.consumer() for line in gpiod.LineIter(chip) if line.offset() < NUM_PINS]
     else:
         gpio_user = [""] * NUM_PINS
@@ -110,8 +122,8 @@ def gpio_add_line_state(gpio_states, row):
     return changed
 
 
-def gpio_update_line_states():
-    gpio_states = get_current_pin_states()
+def gpio_update_line_states(device):
+    gpio_states = get_current_pin_states(device)
     changed = False
 
     for row in LEFT_PINS:
@@ -328,13 +340,15 @@ def main():
     #rich.print(rpipins(Options(sys.argv)))
     options = Options(sys.argv)
 
-    gpio_update_line_states()
+    device = get_gpio_char_device()
+
+    gpio_update_line_states(device)
 
     if options.live:
         with Live(rpipins(options), auto_refresh=True) as live:
             try:
                 while True:
-                    if gpio_update_line_states():
+                    if gpio_update_line_states(device):
                         live.update(rpipins(options), refresh=True)
                     time.sleep(1.0 / options.fps)
             except KeyboardInterrupt: