Merge pull request #819 from sparkfun/Better_Auth_CoPro_Detection

Better Authentication Coprocessor detection - for Torch X2

Author: nseidle

Firmware/RTK_Everywhere/Begin.ino

@@ -95,7 +95,8 @@ void identifyBoard()
         bool husb238Present = i2cIsDevicePresent(i2c_0, 0x08);
 
         // 0x10 - MFI343S00177 Authentication Coprocessor
-        bool mfiPresent = i2cIsDevicePresent(i2c_0, 0x10);
+        // The authentication coprocessor can be asleep. It needs special treatment
+        bool mfiPresent = i2cIsDeviceRegisterPresent(i2c_0, 0x10, 0x00, 0x07);
 
         i2c_0->end();
 
@@ -1803,12 +1804,19 @@ bool i2cBusInitialization(TwoWire *i2cBus, int sda, int scl, int clockKHz)
         // SDA/GND shorted: 14ms, response 5
         timer = millis();
 
-        // If there is nothing else on the bus, the authentication coprocessor can be asleep
-        // Ping it twice to be sure
-        if (addr == 0x10)
-            i2cIsDevicePresent(i2cBus, addr); // Throw away result. Just wake it up.
+        // The authentication coprocessor can be asleep. It needs special treatment
+        if ((addr == 0x10) && (i2cIsDeviceRegisterPresent(i2cBus, addr, 0x00, 0x07)))
+        {
+            if (deviceFound == false)
+            {
+                systemPrintln("I2C Devices:");
+                deviceFound = true;
+            }
 
-        if (i2cIsDevicePresent(i2cBus, addr))
+            systemPrintf("  0x%02X - MFI343S00177 Authentication Coprocessor\r\n", addr);
+            i2cAuthCoPro = i2cBus; // Record the bus
+        }
+        else if (i2cIsDevicePresent(i2cBus, addr))
         {
             if (deviceFound == false)
             {
@@ -1819,7 +1827,7 @@ bool i2cBusInitialization(TwoWire *i2cBus, int sda, int scl, int clockKHz)
             switch (addr)
             {
             default: {
-                systemPrintf("  0x%02X\r\n", addr);
+                systemPrintf("  0x%02X - Unknown\r\n", addr);
                 break;
             }
 
@@ -1833,12 +1841,6 @@ bool i2cBusInitialization(TwoWire *i2cBus, int sda, int scl, int clockKHz)
                 break;
             }
 
-            case 0x10: {
-                systemPrintf("  0x%02X - MFI343S00177 Authentication Coprocessor\r\n", addr);
-                i2cAuthCoPro = i2cBus; // Record the bus
-                break;
-            }
-
             case 0x18: {
                 systemPrintf("  0x%02X - PCA9557 GPIO Expander with Reset\r\n", addr);
                 break;

Firmware/RTK_Everywhere/System.ino

@@ -278,6 +278,31 @@ bool i2cIsDevicePresent(TwoWire *i2cBus, uint8_t deviceAddress)
     return false;
 }
 
+// Read an I2C device register and check for an expected value
+bool i2cIsDeviceRegisterPresent(TwoWire *i2cBus, uint8_t deviceAddress, uint8_t registerAddress, uint8_t expectedValue)
+{
+    int maxRetries = 3;
+
+    while (maxRetries > 0)
+    {
+        maxRetries--;
+        delay(1);
+
+        i2cBus->beginTransmission(deviceAddress);
+        i2cBus->write(registerAddress);
+        if (i2cBus->endTransmission() != 0)
+            continue;
+
+        i2cBus->requestFrom(deviceAddress, (uint8_t)1);
+        if (i2cBus->available())
+        {
+            return (i2cBus->read() == expectedValue);
+        }
+    }
+
+    return false;
+}
+
 // Create a test file in file structure to make sure we can
 bool createTestFile()
 {