Merge pull request #2684 from caternuson/cp_i2c_scan_update

I2C Scanner Code Updates

CircuitPython_Essentials/CircuitPython_I2C_Scan/code.py

@@ -2,49 +2,34 @@
 #
 # SPDX-License-Identifier: MIT
 
-# pylint: disable=bare-except, eval-used, unused-import
-
 """CircuitPython I2C Device Address Scan"""
+# If you run this and it seems to hang, try manually unlocking
+# your I2C bus from the REPL with
+#  >>> import board
+#  >>> board.I2C().unlock()
+
 import time
 import board
-import busio
-
-# List of potential I2C busses
-ALL_I2C = ("board.I2C()", "board.STEMMA_I2C()", "busio.I2C(board.GP1, board.GP0)")
-
-# Determine which busses are valid
-found_i2c = []
-for name in ALL_I2C:
-    try:
-        print("Checking {}...".format(name), end="")
-        bus = eval(name)
-        bus.unlock()
-        found_i2c.append((name, bus))
-        print("ADDED.")
-    except:
-        print("SKIPPED.")
 
-# Scan valid busses
-if len(found_i2c):
-    print("-" * 40)
-    print("I2C SCAN")
-    print("-" * 40)
-    while True:
-        for bus_info in found_i2c:
-            name = bus_info[0]
-            bus = bus_info[1]
-
-            while not bus.try_lock():
-                pass
+# To use default I2C bus (most boards)
+i2c = board.I2C()  # uses board.SCL and board.SDA
+# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 
-            print(
-                name,
-                "addresses found:",
-                [hex(device_address) for device_address in bus.scan()],
-            )
+# To create I2C bus on specific pins
+# import busio
+# i2c = busio.I2C(board.SCL1, board.SDA1)  # QT Py RP2040 STEMMA connector
+# i2c = busio.I2C(board.GP1, board.GP0)    # Pi Pico RP2040
 
-            bus.unlock()
+while not i2c.try_lock():
+    pass
 
+try:
+    while True:
+        print(
+            "I2C addresses found:",
+            [hex(device_address) for device_address in i2c.scan()],
+        )
         time.sleep(2)
-else:
-    print("No valid I2C bus found.")
+
+finally:  # unlock the i2c bus when ctrl-c'ing out of the loop
+    i2c.unlock()

I2C_Scanners/arduino/i2c_scanner/i2c_scanner.ino

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2023 Carter Nelson for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+// --------------------------------------
+// i2c_scanner
+//
+// Modified from https://playground.arduino.cc/Main/I2cScanner/
+// --------------------------------------
+
+#include <Wire.h>
+
+// Set I2C bus to use: Wire, Wire1, etc.
+#define WIRE Wire
+
+void setup() {
+  WIRE.begin();
+
+  Serial.begin(9600);
+  while (!Serial)
+     delay(10);
+  Serial.println("\nI2C Scanner");
+}
+
+
+void loop() {
+  byte error, address;
+  int nDevices;
+
+  Serial.println("Scanning...");
+
+  nDevices = 0;
+  for(address = 1; address < 127; address++ )
+  {
+    // The i2c_scanner uses the return value of
+    // the Write.endTransmisstion to see if
+    // a device did acknowledge to the address.
+    WIRE.beginTransmission(address);
+    error = WIRE.endTransmission();
+
+    if (error == 0)
+    {
+      Serial.print("I2C device found at address 0x");
+      if (address<16)
+        Serial.print("0");
+      Serial.print(address,HEX);
+      Serial.println("  !");
+
+      nDevices++;
+    }
+    else if (error==4)
+    {
+      Serial.print("Unknown error at address 0x");
+      if (address<16)
+        Serial.print("0");
+      Serial.println(address,HEX);
+    }
+  }
+  if (nDevices == 0)
+    Serial.println("No I2C devices found\n");
+  else
+    Serial.println("done\n");
+
+  delay(5000);           // wait 5 seconds for next scan
+}

I2C_Scanners/circuitpython/code.py

@@ -0,0 +1,50 @@
+# SPDX-FileCopyrightText: 2017 Limor Fried for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+# pylint: disable=broad-except, eval-used, unused-import
+
+"""CircuitPython I2C Device Address Scan"""
+import time
+import board
+import busio
+
+# List of potential I2C busses
+ALL_I2C = ("board.I2C()", "board.STEMMA_I2C()", "busio.I2C(board.GP1, board.GP0)")
+
+# Determine which busses are valid
+found_i2c = []
+for name in ALL_I2C:
+    try:
+        print("Checking {}...".format(name), end="")
+        bus = eval(name)
+        bus.unlock()
+        found_i2c.append((name, bus))
+        print("ADDED.")
+    except Exception as e:
+        print("SKIPPED:", e)
+
+# Scan valid busses
+if len(found_i2c):
+    print("-" * 40)
+    print("I2C SCAN")
+    print("-" * 40)
+    while True:
+        for bus_info in found_i2c:
+            name = bus_info[0]
+            bus = bus_info[1]
+
+            while not bus.try_lock():
+                pass
+
+            print(
+                name,
+                "addresses found:",
+                [hex(device_address) for device_address in bus.scan()],
+            )
+
+            bus.unlock()
+
+        time.sleep(2)
+else:
+    print("No valid I2C bus found.")