From 1cb775e2c24aee9328ed479bd2e7270cc37f7b73 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Fri, 6 Sep 2019 06:28:11 +1000
Subject: [PATCH] AP_Compass: probe more addresses for IST8310

IST8310 can be on 4 possible i2c addresses
---
 libraries/AP_Compass/AP_Compass.cpp | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index 83cf1b0a64..2544e23f82 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -708,15 +708,18 @@ void Compass::_probe_external_i2c_compasses(void)
         } else {
             default_rotation = ROTATION_PITCH_180;
         }
+        // probe all 4 possible addresses
+        const uint8_t ist8310_addr[] = { 0x0C, 0x0D, 0x0E, 0x0F };
 
-        FOREACH_I2C_EXTERNAL(i) {
-            ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(i, HAL_COMPASS_IST8310_I2C_ADDR),
-                                                                  true, default_rotation));
-        }
-        
-        FOREACH_I2C_INTERNAL(i) {
-            ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(i, HAL_COMPASS_IST8310_I2C_ADDR),
-                                                                  all_external, default_rotation));
+        for (uint8_t a=0; a<ARRAY_SIZE(ist8310_addr); a++) {
+            FOREACH_I2C_EXTERNAL(i) {
+                ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(i, ist8310_addr[a]),
+                                                                      true, default_rotation));
+            }
+            FOREACH_I2C_INTERNAL(i) {
+                ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(i, ist8310_addr[a]),
+                                                                      all_external, default_rotation));
+            }
         }
     }