From 1fa1149170a9a093f65ba3c19ba60ba210dee5f3 Mon Sep 17 00:00:00 2001
From: jonny <jonny@wwad.de>
Date: Tue, 28 Jan 2025 16:32:57 +0100
Subject: [PATCH] Add custom ADC lib - ADC test success

---
 rpi-scripts/examples/read_analog_inputs.py    |  4 +-
 .../interface_board_libs/adc_mcp3208.py       | 53 +++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 rpi-scripts/interface_board_libs/adc_mcp3208.py

diff --git a/rpi-scripts/examples/read_analog_inputs.py b/rpi-scripts/examples/read_analog_inputs.py
index 84f1c0a..1eaa494 100644
--- a/rpi-scripts/examples/read_analog_inputs.py
+++ b/rpi-scripts/examples/read_analog_inputs.py
@@ -2,7 +2,6 @@
 import os
 import sys
 import time
-from mcp3208 import MCP3208
 
 
 # Include custom files
@@ -15,6 +14,7 @@ from interface_board_pins import ADC_CHANNELS
 adc = MCP3208()
 
 while True:
+        print ("==================")
         for i in range(8):
                 print('ADC[{}]: {:.2f}'.format(i, adc.read(i)))
-        time.sleep(0.5)
\ No newline at end of file
+        time.sleep(0.5)
diff --git a/rpi-scripts/interface_board_libs/adc_mcp3208.py b/rpi-scripts/interface_board_libs/adc_mcp3208.py
new file mode 100644
index 0000000..a560a2f
--- /dev/null
+++ b/rpi-scripts/interface_board_libs/adc_mcp3208.py
@@ -0,0 +1,53 @@
+import spidev
+import time
+
+class MCP3208:
+    def __init__(self, bus=0, device=0):
+        # Initialize SPI bus and device
+        self.spi = spidev.SpiDev()
+        self.spi.open(bus, device)  # Default SPI bus 0, device 0 (you can change as needed)
+        self.spi.max_speed_hz = 1000000  # Adjust based on your needs (e.g., 1MHz)
+        self.spi.mode = 0b00  # Set SPI mode (Mode 0 for MCP3208)
+    
+    def read(self, channel):
+        """
+        Read the ADC value from the specified channel (0-7).
+        """
+        if channel < 0 or channel > 7:
+            raise ValueError("Channel must be between 0 and 7.")
+
+        # MCP3208 sends a 3-byte response, which needs to be processed
+        # Start with the single bit control byte, followed by the channel selection
+        # MCP3208 uses 3 bits for the channel: 0-7
+        # The command byte looks like this:
+        # |  Start | Single-ended | Channel (3 bits) | Don't Care (1 bit) |
+        
+        # Construct the 3-byte command
+        # Start bit (1) | Single-ended (1) | Channel (3 bits) | Don't care (1) | End (1)
+        command = [1, (8 + channel) << 4, 0]
+
+        # Send command and receive the 3-byte result
+        result = self.spi.xfer2(command)
+
+        # Combine the result bytes (result is a list of 3 bytes)
+        # First byte is ignored, we want the 2nd and 3rd bytes for our result
+        value = ((result[1] & 0x03) << 8) | result[2]  # Convert to 10-bit value (0-1023)
+
+        return value
+    
+    def close(self):
+        """Close SPI connection."""
+        self.spi.close()
+
+# Example usage:
+if __name__ == "__main__":
+    adc = MCP3208()
+    try:
+        while True:
+            for i in range(8):
+                adc_value = adc.read(i)
+                print(f'ADC[{i}]: {adc_value}')
+            time.sleep(0.5)
+    finally:
+        adc.close()
+