ist8308: improve configuration

- disable noise suppression filter
 - select more appropriate dynamic range
 - carefully set and clear all ODR, DR, and OSRCNTL bits
 - retry in probe multiple times

src/drivers/magnetometer/isentek/ist8308/IST8308.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -86,14 +86,20 @@ void IST8308::print_status()
 
 int IST8308::probe()
 {
-	const uint8_t WAI = RegisterRead(Register::WAI);
+	_retries = 2;
 
-	if (WAI != Device_ID) {
+	for (int retry = 0; retry < 3; retry++) {
-		DEVICE_DEBUG("unexpected WAI 0x%02x", WAI);
+		const uint8_t WAI = RegisterRead(Register::WAI);
-		return PX4_ERROR;
+
+		if (WAI == Device_ID) {
+			return PX4_OK;
+
+		} else {
+			DEVICE_DEBUG("unexpected WAI 0x%02x", WAI);
+		}
 	}
 
-	return PX4_OK;
+	return PX4_ERROR;
 }
 
 void IST8308::RunImpl()
@@ -240,7 +246,7 @@ bool IST8308::Configure()
 	}
 
 	// 1 Microtesla = 0.01 Gauss
-	_px4_mag.set_scale(1.f / 6.6f * 0.01f); // 6.6 LSB/uT
+	_px4_mag.set_scale(1.f / 13.2f * 0.01f); // 13.2 LSB/uT
 
 	return success;
 }

src/drivers/magnetometer/isentek/ist8308/IST8308.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -103,13 +103,14 @@ private:
 	} _state{STATE::RESET};
 
 	uint8_t _checked_register{0};
-	static constexpr uint8_t size_register_cfg{5};
+	static constexpr uint8_t size_register_cfg{6};
 	register_config_t _register_cfg[size_register_cfg] {
 		// Register               | Set bits, Clear bits
 		{ Register::ACTR,         0, ACTR_BIT::SUSPEND_EN },
-		{ Register::CNTL1,        CNTL1_BIT::NSF_Low, 0 },
+		{ Register::CNTL1,        0, CNTL1_BIT::NSF_DISABLE },
-		{ Register::CNTL2,        CNTL2_BIT::MODE_ODR_50Hz, 0 },
+		{ Register::CNTL2,        CNTL2_BIT::MODE_ODR_50HZ_SET, CNTL2_BIT::MODE_ODR_50HZ_CLEAR },
 		{ Register::CNTL3,        0, CNTL3_BIT::SRST },
-		{ Register::OSRCNTL,      OSRCNTL_BIT::OSR_y_32 | OSRCNTL_BIT::OSR_xz_32, 0 },
+		{ Register::CNTL4,        CNTL4_BIT::DR_200UT_SET, CNTL4_BIT::DR_200UT_CLEAR },
+		{ Register::OSRCNTL,      OSRCNTL_BIT::OSR_Y_32_SET | OSRCNTL_BIT::OSR_XZ_32_SET, OSRCNTL_BIT::OSR_Y_32_CLEAR | OSRCNTL_BIT::OSR_XZ_32_CLEAR },
 	};
 };

src/drivers/magnetometer/isentek/ist8308/iSentek_IST8308_registers.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -96,18 +96,14 @@ enum ACTR_BIT : uint8_t {
 // CNTL1
 enum CNTL1_BIT : uint8_t {
 	// 6:5 NSF[1:0]: Noise Suppression Filter setting
-	NSF_Low    = Bit5,
+	NSF_DISABLE = Bit6 | Bit5, // Disable
-	NSF_Middle = Bit6,
-	NSF_High   = Bit6 | Bit5,
 };
 
 // CNTL2
 enum CNTL2_BIT : uint8_t {
 	// 4:0 MODE [4:0]: Operation mode setting
-	MODE_ODR_10Hz  = Bit1,        // 5’h02: Continuous Measurement Mode with ODR 10Hz
+	MODE_ODR_50HZ_SET   = Bit2 | Bit1, // 5’h06: Continuous Measurement Mode with ODR 50Hz
-	MODE_ODR_20Hz  = Bit2,        // 5’h04: Continuous Measurement Mode with ODR 20Hz
+	MODE_ODR_50HZ_CLEAR = Bit3 | Bit0,
-	MODE_ODR_50Hz  = Bit2 | Bit1, // 5’h06: Continuous Measurement Mode with ODR 50Hz
-	MODE_ODR_100Hz = Bit3,        // 5’h08: Continuous Measurement Mode with ODR 100Hz
 };
 
 // CNTL3
@@ -115,15 +111,22 @@ enum CNTL3_BIT : uint8_t {
 	SRST = Bit0, // Soft reset, perform the same routine as POR
 };
 
+// CNTL4
+enum CNTL4_BIT : uint8_t {
+	// DR [1:0]: Sensor Dynamic Range and Sensitivity setting
+	DR_200UT_SET   = Bit0, // ±200 uT, Sensitivity=13.2 LSB/uT
+	DR_200UT_CLEAR = Bit1
+};
+
 // OSRCNTL
 enum OSRCNTL_BIT : uint8_t {
 	// 5:3
-	OSR_y_16 = Bit5,        // 3’b100: OSR=16 (ODRmax=100) (Default)
+	OSR_Y_32_SET    = Bit5 | Bit3, // 3’b101: OSR=32 (ODRmax=50)
-	OSR_y_32 = Bit5 | Bit3, // 3’b101: OSR=32 (ODRmax=50)
+	OSR_Y_32_CLEAR  = Bit4,
 
 	// 2:0
-	OSR_xz_16 = Bit2,        // 3’b100: OSR=16 (ODRmax=100) (Default)
+	OSR_XZ_32_SET   = Bit2 | Bit0, // 3’b101: OSR=32 (ODRmax=50)
-	OSR_xz_32 = Bit2 | Bit0, // 3’b101: OSR=32 (ODRmax=50)
+	OSR_XZ_32_CLEAR = Bit1,
 };
 
 } // namespace iSentek_IST8308