From 730f7cf41567a2b3fbc6b9187d30c57bbdeac470 Mon Sep 17 00:00:00 2001
From: "Ben V. Brown" <Ralim@Ralimtek.com>
Date: Sat, 12 Feb 2022 11:13:41 +1100
Subject: [PATCH] SC7A20 handle address

---
 source/Core/Drivers/SC7A20.cpp       | 20 ++++++--
 source/Core/Drivers/SC7A20.hpp       |  3 +-
 source/Core/Drivers/SC7A20_defines.h | 74 +++++++++++++++-------------
 3 files changed, 58 insertions(+), 39 deletions(-)

diff --git a/source/Core/Drivers/SC7A20.cpp b/source/Core/Drivers/SC7A20.cpp
index b6b7ee4f..cd37e584 100644
--- a/source/Core/Drivers/SC7A20.cpp
+++ b/source/Core/Drivers/SC7A20.cpp
@@ -9,15 +9,29 @@
 #include <SC7A20_defines.h>
 #include <array>
 
+uint8_t SC7A20::activeAddress;
+
 bool SC7A20::detect() {
   if (FRToSI2C::probe(SC7A20_ADDRESS)) {
     // Read chip id to ensure its not an address collision
     uint8_t id = 0;
     if (FRToSI2C::Mem_Read(SC7A20_ADDRESS, SC7A20_WHO_AMI_I, &id, 1)) {
-      return id == 0b00010001;
+      if (id == SC7A20_WHO_AM_I_VALUE) {
+        activeAddress = SC7A20_ADDRESS;
+        return true;
+      }
+    }
+  }
+  if (FRToSI2C::probe(SC7A20_ADDRESS2)) {
+    // Read chip id to ensure its not an address collision
+    uint8_t id = 0;
+    if (FRToSI2C::Mem_Read(SC7A20_ADDRESS2, SC7A20_WHO_AMI_I, &id, 1)) {
+      if (id == SC7A20_WHO_AM_I_VALUE) {
+        activeAddress = SC7A20_ADDRESS2;
+        return true;
+      }
     }
   }
-
   return false;
 }
 
@@ -50,7 +64,7 @@ bool SC7A20::initalize() {
   // Hysteresis is set to ~ 16 counts
   // Theta blocking is set to 0b10
 
-  return FRToSI2C::writeRegistersBulk(SC7A20_ADDRESS, i2c_registers, sizeof(i2c_registers) / sizeof(i2c_registers[0]));
+  return FRToSI2C::writeRegistersBulk(activeAddress, i2c_registers, sizeof(i2c_registers) / sizeof(i2c_registers[0]));
 }
 
 void SC7A20::getAxisReadings(int16_t &x, int16_t &y, int16_t &z) {
diff --git a/source/Core/Drivers/SC7A20.hpp b/source/Core/Drivers/SC7A20.hpp
index f7bba230..f7cd9776 100644
--- a/source/Core/Drivers/SC7A20.hpp
+++ b/source/Core/Drivers/SC7A20.hpp
@@ -17,7 +17,7 @@ public:
   static bool initalize();
   // 1 = rh, 2,=lh, 8=flat
   static Orientation getOrientation() {
-    uint8_t val = ((FRToSI2C::I2C_RegisterRead(SC7A20_ADDRESS, SC7A20_INT2_SOURCE) >> 2) - 1);
+    uint8_t val = ((FRToSI2C::I2C_RegisterRead(activeAddress, SC7A20_INT2_SOURCE) >> 2) - 1);
     if (val == 1)
       return Orientation::ORIENTATION_LEFT_HAND;
     else if (val == 4 || val == 0)
@@ -28,6 +28,7 @@ public:
   static void getAxisReadings(int16_t &x, int16_t &y, int16_t &z);
 
 private:
+  static uint8_t activeAddress;
 };
 
 #endif /* CORE_DRIVERS_BMA223_HPP_ */
diff --git a/source/Core/Drivers/SC7A20_defines.h b/source/Core/Drivers/SC7A20_defines.h
index fc3d6d6d..85fc5720 100644
--- a/source/Core/Drivers/SC7A20_defines.h
+++ b/source/Core/Drivers/SC7A20_defines.h
@@ -1,5 +1,5 @@
 /*
- * BMA223_defines.h
+ * SC7A20_defines.h
  *
  *  Created on: 18 Sep. 2020
  *      Author: Ralim
@@ -8,39 +8,43 @@
 #ifndef CORE_DRIVERS_SC7A20_DEFINES_H_
 #define CORE_DRIVERS_SC7A20_DEFINES_H_
 
-#define SC7A20_ADDRESS       0x18 << 1
-#define SC7A20_WHO_AMI_I     0x0F
-#define SC7A20_CTRL_REG1     0x20
-#define SC7A20_CTRL_REG2     0x21
-#define SC7A20_CTRL_REG3     0x22
-#define SC7A20_CTRL_REG4     0x23
-#define SC7A20_CTRL_REG5     0x24
-#define SC7A20_CTRL_REG6     0x25
-#define SC7A20_REFERENCE     0x26
-#define SC7A20_STATUS_REG    0x27
-#define SC7A20_OUT_X_L       0x28
-#define SC7A20_OUT_X_H       0x29
-#define SC7A20_OUT_Y_L       0x2A
-#define SC7A20_OUT_Y_H       0x2B
-#define SC7A20_OUT_Z_L       0x2C
-#define SC7A20_OUT_Z_H       0x2D
-#define SC7A20_FIFO_CTRL     0x2E
-#define SC7A20_FIFO_SRC      0x2F
-#define SC7A20_INT1_CFG      0x30
-#define SC7A20_INT1_SOURCE   0x31
-#define SC7A20_INT1_THS      0x32
-#define SC7A20_INT1_DURATION 0x33
-#define SC7A20_INT2_CFG      0x34
-#define SC7A20_INT2_SOURCE   0x35
-#define SC7A20_INT2_THS      0x36
-#define SC7A20_INT2_DURATION 0x37
-#define SC7A20_CLICK_CFG     0x38
-#define SC7A20_CLICK_SRC     0x39
-#define SC7A20_CLICK_THS     0x3A
-#define SC7A20_TIME_LIMIT    0x3B
-#define SC7A20_TIME_LATENCY  0x3C
-#define SC7A20_TIME_WINDOW   0x3D
-#define SC7A20_ACT_THS       0x3E
-#define SC7A20_ACT_DURATION  0x3F
+#define SC7A20_ADDRESS 0x18 << 1
+// Sometimes the SC7A20 turns up programmed to impersonate the LIS2DH12
+#define SC7A20_ADDRESS2 (25 << 1)
+
+#define SC7A20_WHO_AM_I_VALUE (0b00010001)
+#define SC7A20_WHO_AMI_I      0x0F
+#define SC7A20_CTRL_REG1      0x20
+#define SC7A20_CTRL_REG2      0x21
+#define SC7A20_CTRL_REG3      0x22
+#define SC7A20_CTRL_REG4      0x23
+#define SC7A20_CTRL_REG5      0x24
+#define SC7A20_CTRL_REG6      0x25
+#define SC7A20_REFERENCE      0x26
+#define SC7A20_STATUS_REG     0x27
+#define SC7A20_OUT_X_L        0x28
+#define SC7A20_OUT_X_H        0x29
+#define SC7A20_OUT_Y_L        0x2A
+#define SC7A20_OUT_Y_H        0x2B
+#define SC7A20_OUT_Z_L        0x2C
+#define SC7A20_OUT_Z_H        0x2D
+#define SC7A20_FIFO_CTRL      0x2E
+#define SC7A20_FIFO_SRC       0x2F
+#define SC7A20_INT1_CFG       0x30
+#define SC7A20_INT1_SOURCE    0x31
+#define SC7A20_INT1_THS       0x32
+#define SC7A20_INT1_DURATION  0x33
+#define SC7A20_INT2_CFG       0x34
+#define SC7A20_INT2_SOURCE    0x35
+#define SC7A20_INT2_THS       0x36
+#define SC7A20_INT2_DURATION  0x37
+#define SC7A20_CLICK_CFG      0x38
+#define SC7A20_CLICK_SRC      0x39
+#define SC7A20_CLICK_THS      0x3A
+#define SC7A20_TIME_LIMIT     0x3B
+#define SC7A20_TIME_LATENCY   0x3C
+#define SC7A20_TIME_WINDOW    0x3D
+#define SC7A20_ACT_THS        0x3E
+#define SC7A20_ACT_DURATION   0x3F
 
 #endif /* CORE_DRIVERS_BMA223_DEFINES_H_ */