From 70235f4b62fda537cb001c6c5ee4c8e7f7573428 Mon Sep 17 00:00:00 2001
From: Davit Babayan <davitb2013@gmail.com>
Date: Tue, 21 Jan 2025 18:48:18 -0800
Subject: [PATCH] add address validation to initialization

---
 adafruit_tca9548a.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/adafruit_tca9548a.py b/adafruit_tca9548a.py
index c766176..ed23649 100644
--- a/adafruit_tca9548a.py
+++ b/adafruit_tca9548a.py
@@ -103,6 +103,18 @@ class TCA9548A:
     """Class which provides interface to TCA9548A I2C multiplexer."""
 
     def __init__(self, i2c: I2C, address: int = _DEFAULT_ADDRESS) -> None:
+        tries = 0
+        while not i2c.try_lock():
+            if (tries >= 200):
+                raise ValueError("Unable to lock I2C bus.")
+            tries += 1
+            time.sleep(0)
+
+        if address not in i2c.scan():
+            i2c.unlock()
+            raise ValueError(f"No TCA9548A detected at {hex(address)}.")
+        i2c.unlock()
+
         self.i2c = i2c
         self.address = address
         self.channels = [None] * 8