Tyler Sisk
Library to interface to the TI BQ27441, a fuel gauge monitor
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battery-gauge-bq27441
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u-blox
Diff: bq27441.cpp
- Revision:
- 1:566163f17cde
- Child:
- 2:93310a83401a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/bq27441.cpp Mon Apr 10 11:18:51 2017 +0100
@@ -0,0 +1,1192 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 u-blox
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file bq27441.cpp
+ * This file defines the API to the TI BQ27441 battery gauge chip.
+ */
+
+/// Define these to print debug information.
+//#define DEBUG_BQ27441
+//#define DEBUG_BQ27441_BLOCK_DATA
+
+#include <mbed.h>
+#include <battery_gauge_bq27441.h>
+
+#ifdef DEBUG_BQ27441
+# include <stdio.h>
+#endif
+
+// ----------------------------------------------------------------
+// COMPILE-TIME MACROS
+// ----------------------------------------------------------------
+
+/// How many loops to wait for a configuration update to be permitted.
+// Experience suggests that the limit really does need to be this large.
+#define CONFIG_UPDATE_LOOPS 200
+
+/// How long to delay when running around the config update loop.
+#define CONFIG_UPDATE_LOOP_DELAY_MS 100
+
+/// How long to wait for all the ADC readings to be performed.
+#define ADC_READ_WAIT_MS 1000
+
+/// Delay after the last config update before we can unseal the
+// chip again (see section 6.4.5.1.1 of the BQ27441 technical
+// reference manual).
+#define UNSEAL_DELAY_MS 4000
+
+// ----------------------------------------------------------------
+// PRIVATE VARIABLES
+// ----------------------------------------------------------------
+
+// ----------------------------------------------------------------
+// GENERIC PRIVATE FUNCTIONS
+// ----------------------------------------------------------------
+
+/// Read two bytes from an address.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::getTwoBytes (uint8_t registerAddress, uint16_t *pBytes)
+{
+ bool success = false;
+ char data[3];
+
+ if (gpI2c != NULL) {
+ // Send a command to read from registerAddress
+ data[0] = registerAddress;
+ data[1] = 0;
+ data[2] = 0;
+
+ if ((gpI2c->write(gAddress, &(data[0]), 1) == 0) &&
+ (gpI2c->read(gAddress, &(data[1]), 2) == 0)) {
+ success = true;
+ if (pBytes) {
+ *pBytes = (((uint16_t) data[2]) << 8) + data[1];
+ }
+ }
+ }
+
+ return success;
+}
+
+/// Compute the checksum over a block of data.
+uint8_t BatteryGaugeBq27441::computeChecksum(const char * pData)
+{
+ uint8_t checkSum = 0;
+ uint8_t x;
+
+ if (pData != NULL) {
+#ifdef DEBUG_BQ27441_BLOCK_DATA
+ printf ("BatteryGaugeBq27441 (I2C 0x%02x): computing check sum on data block.\n", gAddress >> 1);
+ printf (" 0 1 2 3 4 5 6 7 8 9 A B C D E F\n");
+#endif
+ for (x = 1; x <= 32; x++) {
+ checkSum += *pData;
+
+#ifdef DEBUG_BQ27441_BLOCK_DATA
+ if (x % 16 == 8) {
+ printf ("%02x ", *pData);
+ } else if (x % 16 == 0) {
+ printf ("%02x\n", *pData);
+ } else {
+ printf ("%02x-", *pData);
+ }
+#endif
+ pData++;
+ }
+
+ checkSum = 0xff - checkSum;
+ }
+
+#ifdef DEBUG_BQ27441_BLOCK_DATA
+ if (x % 16 != 1) {
+ printf("\n");
+ }
+
+ printf ("BatteryGaugeBq27441 (I2C 0x%02x): check sum is 0x%02x.\n", gAddress >> 1, checkSum);
+#endif
+
+ return checkSum;
+}
+
+/// Read data of a given length and class ID.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::readExtendedData(uint8_t subClassId, int32_t offset, int32_t length, char * pData)
+{
+ bool success = false;
+ bool wasSealed = false;
+ char block[32];
+ char data[3];
+
+ if ((gpI2c != NULL) && (length <= 32) && (pData != NULL)) {
+
+ // The offset + length combination must not cross a 32-byte boundary
+ if (offset / 32 == (offset + length - 1) / 32) {
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): preparing to read %d byte(s) from offset %d of sub-class %d.\n", gAddress >> 1, length, offset, subClassId);
+#endif
+ // Handle unsealing
+ wasSealed = isSealed();
+ if (!wasSealed || unseal(gSealCode)) {
+
+ // Enable Block Data Control (0x61)
+ data[0] = 0x61;
+ data[1] = 0;
+
+ if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
+ // Write sub-class ID using Data Block Class (0x3e)
+ data[0] = 0x3e;
+ data[1] = subClassId;
+
+ if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
+ // Write offset using Block Offset (0x3f) and then
+ // read the data block
+ data[0] = 0x3f;
+ data[1] = offset / 32;
+
+ if ((gpI2c->write(gAddress, &(data[0]), 2, true) == 0) &&
+ (gpI2c->read(gAddress, &(block[0]), 32) == 0)) {
+ // Compute the block checksum and then read it
+ data[2] = computeChecksum(&(block[0]));
+ data[0] = 0x60;
+ data[1] = 0;
+
+ if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
+ (gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
+
+ // Does the checksum match?
+ if (data[1] == data[2]) {
+ // If so read the new data from the block data area at 0x40 plus
+ // the offset (plus the Block Offset already written)
+ data[0] = 0x40 + (offset % 32);
+
+ if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
+ (gpI2c->read(gAddress, pData, length) == 0)) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): read successful.\n", gAddress >> 1);
+#endif
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): couldn't read all %d bytes of config.\r", gAddress >> 1, length);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): checksum on data block incorrect (expected 0x%02x, received 0x%02x).\n", gAddress >> 1, data[2], data[1]);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to read Block Data Checksum for config.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to write Block Offset (%d), or maybe read the data block, for config.\n", gAddress >> 1, data[1]);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable set sub-class ID (0x%02x) for config.\n", gAddress >> 1, subClassId);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to set Block Data Control for config.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to unseal chip.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): offset (%d) is in different 32 byte block to offset + length (%d) [length is %d].\n", gAddress >> 1, offset, offset + length, length);
+#endif
+ }
+ }
+
+ // Reseal if required, and fail if it fails
+ if (wasSealed) {
+ if (!seal()) {
+ success = false;
+ }
+ }
+
+ return success;
+}
+
+/// Write data of a given length and class ID to a given offset. This code taken from
+// section 3.1 of the SLUUAC9A application technical reference manual with hints from:
+// https://github.com/sparkfun/SparkFun_BQ27441_Arduino_Library/blob/master/src/SparkFunBQ27441.cpp.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::writeExtendedData(uint8_t subClassId, int32_t offset, int32_t length, const char * pData)
+{
+ bool success = false;
+ bool wasSealed = false;
+ char data[3 + 32];
+ char block[32];
+ uint16_t answer;
+ uint32_t count = 0;
+
+ if ((gpI2c != NULL) && (length <= 32) && (pData != NULL)) {
+
+ // The offset + length combination must not cross a 32-byte boundary
+ if (offset / 32 == (offset + length - 1) / 32) {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): preparing to write %d byte(s) to offset %d of sub-class %d.\n", gAddress >> 1, length, offset, subClassId);
+#endif
+ // Handle unsealing
+ wasSealed = isSealed();
+ if (!wasSealed || unseal(gSealCode)) {
+
+ // Send Config Update (command 0x13)
+ data[0] = 0;
+ data[1] = 0x13;
+ data[2] = 0;
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ // Wait for CONFIGUPDATE to be set in Flags register (bit 4)
+ count = 0;
+ do {
+ answer = 0;
+ getTwoBytes(0x06, &answer);
+ count++;
+ wait_ms(CONFIG_UPDATE_LOOP_DELAY_MS);
+ } while (((answer & (1 << 4)) == 0) && (count < CONFIG_UPDATE_LOOPS));
+
+ if ((answer & (1 << 4)) != 0) {
+ // Enable Block Data Control (0x61)
+ data[0] = 0x61;
+ data[1] = 0;
+
+ if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
+ // Write sub-class ID using Data Block Class (0x3e)
+ data[0] = 0x3e;
+ data[1] = subClassId;
+
+ if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
+ // Write offset using Block Offset (0x3f) and then
+ // read the data block
+ data[0] = 0x3f;
+ data[1] = offset / 32;
+
+ if ((gpI2c->write(gAddress, &(data[0]), 2, true) == 0) &&
+ (gpI2c->read(gAddress, &(block[0]), 32) == 0)) {
+ // Compute the existing block checksum and then read it
+ data[2] = computeChecksum(&(block[0]));
+ data[0] = 0x60;
+ data[1] = 0;
+
+ if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
+ (gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
+
+ // Does the checksum match?
+ if (data[1] == data[2]) {
+ // If so write the new data to the block data area at 0x40 plus the offset (plus the Block Offset already written)
+ // NOTE: I tried doing this as two separate writes, one of the offset and then another of the
+ // data block (so that I could use pData directly rather than having to extend the local
+ // data array by 32) but the chip didn't like that, hence we have to copy pData into the
+ // local array and do a single contiguous write.
+ data[0] = 0x40 + (offset % 32);
+ memcpy (&(data[1]), pData, length);
+
+ if (gpI2c->write(gAddress, &(data[0]), length + 1) == 0) {
+ // Also write the data into our local block variable
+ // on top of the previously read data and use
+ // that to compute the new block checksum, then write it
+ memcpy (&(block[offset % 32]), pData, length);
+ data[0] = 0x60;
+ data[1] = computeChecksum(&(block[0]));
+
+ if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
+ // Exit config mode with SOFT_RESET command 0x42
+ data[0] = 0;
+ data[1] = 0x42;
+ data[2] = 0;
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ // Finally, wait for CONFIGUPDATE to be unset in Flags register (bit 4)
+ count = 0;
+ do {
+ answer = 0xFFFF;
+ getTwoBytes(0x06, &answer);
+ count++;
+ wait_ms(CONFIG_UPDATE_LOOP_DELAY_MS);
+ } while (((answer & (1 << 4)) != 0) && (count < CONFIG_UPDATE_LOOPS));
+
+ if ((answer & (1 << 4)) == 0) {
+ success = true;
+ // Wait around for 4 seconds if there has been a config update
+ // and there is a danger that we might have to unseal the device
+ // Note: would be nice if we could note the time and do other
+ // things but the timer is restarted when certain commands are sent,
+ // so it is better to be dumb
+ if (wasSealed) {
+ wait_ms(UNSEAL_DELAY_MS);
+ }
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): write successful.\n", gAddress >> 1);
+#endif
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): Flags register didn't show config update flag unset in time (0x%04x).\n", gAddress >> 1, answer);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to write config update exit after update.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): checksum on modified data block incorrect (0x%02x) during config update.\n", gAddress >> 1, data[1]);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): couldn't write all %d bytes during config update.\n", gAddress >> 1, length);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): checksum on read data block incorrect (expected 0x%02x, received 0x%02x).\n", gAddress >> 1, data[2], data[1]);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to read Block Data Checksum for config update.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to write Block Offset (%d), or possibly read the data block, for config update.\n", gAddress >> 1, data[1]);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to set sub-class ID (0x%02x) for config update.\r", gAddress >> 1, subClassId);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to set Block Data Control for config update.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): Flags register didn't show config update flag set in time (0x%04x).\n", gAddress >> 1, answer);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to write to control register for config update.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unable to unseal chip.\n", gAddress >> 1);
+#endif
+ }
+ } else {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): offset (%d) is in different 32 byte block to offset + length (%d) [length is %d].\n", gAddress >> 1, offset, offset + length, length);
+#endif
+ }
+ }
+
+ // If the write succeeded the exit from config update state will
+ // re-seal things. If it failed, we need to re-seal the device
+ // manually if it was previously sealed.
+ if (!success && wasSealed) {
+ if (!seal()) {
+ success = false;
+ }
+ }
+
+ return success;
+}
+
+
+/// Check if the chip is SEALED or UNSEALED.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::isSealed(void)
+{
+ bool sealed = false;
+ char data[3];
+ uint16_t controlStatus;
+
+ // Send a control command to read the control status register
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x00; // First byte of CONTROL_STATUS sub-command (0x00)
+ data[2] = 0x00; // Second byte of CONTROL_STATUS sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ if (getTwoBytes (0, &controlStatus)) {
+ // Bit 5 of the high byte is set to 1 if the device is sealed
+ if (controlStatus & (1 << 13)) {
+ sealed = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): is sealed (control status 0x%04x).\r\n", gAddress >> 1, controlStatus);
+ } else {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): is unsealed (control status 0x%04x).\r\n", gAddress >> 1, controlStatus);
+#endif
+ }
+ }
+ }
+
+ return sealed;
+}
+
+/// Put the chip into SEALED mode.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::seal(void)
+{
+ bool success = false;
+ char data[3];
+ uint16_t controlStatus;
+
+ // Send a SEALED sub-command
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x20; // First byte of SEALED sub-command (0x20)
+ data[2] = 0x00; // Second byte of SEALED sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ // Check for success by reading the control status register
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x00; // First byte of CONTROL_STATUS sub-command (0x00)
+ data[2] = 0x00; // Second byte of CONTROL_STATUS sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ if (getTwoBytes (0, &controlStatus)) {
+ // Bit 5 of the high byte is set to 1 if the device is sealed
+ if (controlStatus & (1 << 13)) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): now sealed.\n", gAddress >> 1);
+ } else {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): seal failed (control status 0x%04x).\n", gAddress >> 1, controlStatus);
+#endif
+ }
+ }
+ }
+ }
+
+ return success;
+}
+
+/// Send the seal code to the device to unseal it.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::unseal(uint16_t sealCode)
+{
+ bool success = false;
+ char data[3];
+ uint16_t controlStatus;
+
+ // Send the unseal code to the control register
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = (char) sealCode; // First byte of code
+ data[2] = (char) (sealCode >> 8); // Second byte of code (register address will auto-increment)
+
+
+ if ((gpI2c->write(gAddress, &(data[0]), 3) == 0) &&
+ (gpI2c->write(gAddress, &(data[0]), 3) == 0)) {
+ // Check for success by reading the control status register
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x00; // First byte of CONTROL_STATUS sub-command (0x00)
+ data[2] = 0x00; // Second byte of CONTROL_STATUS sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ if (getTwoBytes (0, &controlStatus)) {
+ // Bit 5 of the high byte is 0 if the device is unsealed
+ if ((controlStatus & (1 << 13)) == 0) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): now unsealed with seal code 0x%04x (control status 0x%04x).\n", gAddress >> 1, sealCode, controlStatus);
+ } else {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): unseal failed (with seal code 0x%04x, control status 0x%04x).\n", gAddress >> 1, sealCode, controlStatus);
+#endif
+ }
+ }
+ }
+ }
+
+ return success;
+}
+
+/// Make sure that the device is awake and has taken a reading.
+// Note: the function does its own locking of gpI2C so that it isn't
+// locked for the entire time we wait for ADC readings to complete.
+bool BatteryGaugeBq27441::makeAdcReading(void)
+{
+ bool success = false;
+ char data[3];
+
+ // Send CLEAR_HIBERNATE
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x12; // First byte of CLEAR_HIBERNATE sub-command (0x12)
+ data[2] = 0x00; // Second byte of CLEAR_HIBERNATE sub-command (0x00) (register address will auto-increment)
+
+ gpI2c->lock();
+ success = (gpI2c->write(gAddress, &(data[0]), 3) == 0);
+ gpI2c->unlock();
+ wait_ms (ADC_READ_WAIT_MS);
+
+ return success;
+}
+
+/// Set Hibernate mode.
+// Note: gpI2c should be locked before this is called.
+bool BatteryGaugeBq27441::setHibernate(void)
+{
+ char data[3];
+
+ // Send SET_HIBERNATE
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x11; // First byte of SET_HIBERNATE sub-command (0x11)
+ data[2] = 0x00; // Second byte of SET_HIBERNATE sub-command (0x00) (register address will auto-increment)
+
+ return (gpI2c->write(gAddress, &(data[0]), 3) == 0);
+}
+
+//----------------------------------------------------------------
+// PUBLIC FUNCTIONS
+// ----------------------------------------------------------------
+
+/// Constructor.
+BatteryGaugeBq27441::BatteryGaugeBq27441(void)
+{
+ gpI2c = NULL;
+ gReady = false;
+ gGaugeOn = false;
+ gSealCode = 0;
+}
+
+/// Destructor.
+BatteryGaugeBq27441::~BatteryGaugeBq27441(void)
+{
+}
+
+/// Initialise ourselves.
+bool BatteryGaugeBq27441::init (I2C * pI2c, uint8_t address, uint16_t sealCode)
+{
+ uint16_t answer;
+ char data[4];
+
+ gpI2c = pI2c;
+ gAddress = address << 1;
+ gSealCode = sealCode;
+
+ if (gpI2c != NULL) {
+ gpI2c->lock();
+
+ // Send a control command to read the firmware version
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x02; // First byte of FW_VERSION sub-command (0x02)
+ data[2] = 0x00; // Second byte of FW_VERSION sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ if (getTwoBytes (0, &answer)) {
+ // The expected response is 0x0109
+ if (((answer >> 8) == 0x01) && ((answer & 0xff) == 0x09)) {
+#ifdef DEBUG_BQ27441
+ if (readExtendedData(112, 0, 4, &(data[0]))) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): seal code stored in chip is 0x%02x%02x%02x%02x.\n", gAddress >> 1, data[0], data[1], data[2], data[3]);
+ }
+#endif
+ // Set the Sleep Current to the maximum value so that, if
+ // we tell the chip to go to sleep mode, it will do so
+ // straight away. Sleep Current is offset 31 in the State
+ // sub-class (82) and max value is 1000. Since offset 31
+ // and a length of 2 crosses a 32 bytes boundary this needs
+ // two separate writes.
+ data[0] = (char) (1000 >> 8);
+ data[1] = (char) 1000;
+
+ if (writeExtendedData(82, 31, 1, &(data[0])) &&
+ writeExtendedData(82, 32, 1, &(data[1]))) {
+ // Now enter Hibernate mode to minimise power consumption
+ // Need to set either the Hibernate Current or Hibernate Voltage value
+ // to max, otherwise we won't hibernate, then set the SET_HIBERNATE
+ // bit. Here we set Hibernate V element (offset 9) in the Power
+ // sub-class (68) to its max value (see section 6.4.1.6.2 of the
+ // BQ27441 technical reference manual).
+ // Note: the cell must also be "relaxed" for this to occur and so
+ // the chip may still not enter Hibernate mode for a little while.
+ data[0] = (char) (5000 >> 8);
+ data[1] = (char) 5000;
+
+ if (writeExtendedData(68, 9, 2, &(data[0]))) {
+ // Now send SET_HIBERNATE
+ gReady = setHibernate();
+ }
+ }
+ }
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): read 0x%04x as FW_VERSION, expected 0x0109.\n", gAddress >> 1, answer);
+#endif
+ }
+ }
+ gpI2c->unlock();
+ }
+
+#ifdef DEBUG_BQ27441
+ if (gReady) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): handler initialised.\r\n", gAddress >> 1);
+ } else {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): init NOT successful.\r\n", gAddress >> 1);
+ }
+#endif
+
+ return gReady;
+}
+
+/// Switch on the battery capacity monitor.
+bool BatteryGaugeBq27441::enableGauge (bool isSlow)
+{
+ bool success = false;
+ char data[3];
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Make sure that we are not in hibernate
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x12; // First byte of CLEAR_HIBERNATE sub-command (0x12)
+ data[2] = 0x00; // Second byte of CLEAR_HIBERNATE sub-command (0x00)
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ gGaugeOn = true;
+ // Read the OpConfig register which is in the Registers sub-class
+ // (64) at offset 0.
+ if (readExtendedData(64, 0, 2, &(data[0]))) {
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): OpConfig is 0x%02x%02x.\r\n", gAddress >> 1, data[0], data[1]);
+#endif
+ // SLEEP mode is bit 5 of the low byte of OpConfig. In SLEEP
+ // mode a reading is taken every 20 seconds.
+ if (isSlow && ((data[1] & (1 << 5)) == 0)) {
+ // Set the SLEEP bit 'cos it's not set and needs to be
+ data[1] |= 1 << 5;
+ // Write the new value back
+ success = writeExtendedData(64, 0, 2, &(data[0]));
+#ifdef DEBUG_BQ27441
+ if (success) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): OpConfig becomes 0x%02x%02x.\r\n", gAddress >> 1, data[0], data[1]);
+ }
+#endif
+ } else if (!isSlow && ((data[1] & (1 << 5)) != 0)) {
+ // Clear the SLEEP bit 'cos it's set and shouldn't be
+ data[1] &= ~(1 << 5);
+ // Write the new value back
+ success = writeExtendedData(64, 0, 2, &(data[0]));
+#ifdef DEBUG_BQ27441
+ if (success) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): OpConfig becomes 0x%02x%02x.\r\n", gAddress >> 1, data[0], data[1]);
+ }
+#endif
+ } else {
+ success = true;
+ }
+ }
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Switch off the battery capacity monitor.
+bool BatteryGaugeBq27441::disableGauge (void)
+{
+ bool success = false;
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Send SET_HIBERNATE
+ if (setHibernate()) {
+ success = true;
+ gGaugeOn = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Check whether a battery has been detected or not.
+bool BatteryGaugeBq27441::isBatteryDetected (void)
+{
+ bool isDetected = false;
+ uint16_t data;
+
+ if (gReady && (gpI2c != NULL)) {
+
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read from the flags register address
+ if (getTwoBytes (0x06, &data)) {
+
+ // If bit 3 is set then a battery has been detected
+ if (data & (1 << 3)) {
+ isDetected = true;
+ }
+
+#ifdef DEBUG_BQ27441
+ if (isDetected) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): battery detected (flags 0x%04x).\n", gAddress >> 1, data);
+ } else {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): battery NOT detected (flags 0x%04x).\n", gAddress >> 1, data);
+ }
+#endif
+ }
+
+ // Set hibernate again if we are not monitoring
+ if (!gGaugeOn) {
+ setHibernate();
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return isDetected;
+}
+
+/// Get the temperature of the chip.
+bool BatteryGaugeBq27441::getTemperature (int32_t *pTemperatureC)
+{
+ bool success = false;
+ int32_t temperatureC = 0;
+ uint16_t data;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read from the temperature register address
+ if (getTwoBytes (0x02, &data)) {
+ success = true;
+
+ // The answer is in units of 0.1 K, so convert to C
+ temperatureC = ((int32_t) data / 10) - 273;
+
+ if (pTemperatureC) {
+ *pTemperatureC = temperatureC;
+ }
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): chip temperature %.1f K, so %d C.\n", gAddress >> 1, ((float) data) / 10, temperatureC);
+#endif
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Get the voltage of the battery.
+bool BatteryGaugeBq27441::getVoltage (int32_t *pVoltageMV)
+{
+ bool success = false;
+ uint16_t data = 0;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read from the voltage register address
+ if (getTwoBytes (0x04, &data)) {
+ success = true;
+
+ // The answer is in mV
+ if (pVoltageMV) {
+ *pVoltageMV = (int32_t) data;
+ }
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): battery voltage %.3f V.\n", gAddress >> 1, ((float) data) / 1000);
+#endif
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Get the current flowing from the battery.
+bool BatteryGaugeBq27441::getCurrent (int32_t *pCurrentMA)
+{
+ bool success = false;
+ int32_t currentMA = 0;
+ uint16_t data;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read from the average current register address
+ if (getTwoBytes (0x10, &data)) {
+ success = true;
+
+ if (pCurrentMA) {
+ *pCurrentMA = currentMA;
+ }
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): current %d mA.\n", gAddress >> 1, currentMA);
+#endif
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Get the remaining battery capacity.
+bool BatteryGaugeBq27441::getRemainingCapacity (int32_t *pCapacityMAh)
+{
+ bool success = false;
+ uint16_t data = 0;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read from the RemainingCapacity register address
+
+ if (getTwoBytes (0x0c, &data)) {
+ success = true;
+
+ // The answer is in mAh
+ if (pCapacityMAh) {
+ *pCapacityMAh = (int32_t) data;
+ }
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): remaining battery capacity %u mAh.\n", gAddress >> 1, data);
+#endif
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Get the battery percentage remaining
+bool BatteryGaugeBq27441::getRemainingPercentage (int32_t *pBatteryPercent)
+{
+ bool success = false;
+ uint16_t data = 0;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+
+ // Wake up and take a reading if we have to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ // Read from the StateOfCharge register address
+ if (getTwoBytes (0x1c, &data)) {
+ success = true;
+
+ if (pBatteryPercent) {
+ *pBatteryPercent = (int32_t) data;
+ }
+
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): remaining battery percentage %u%%.\n", gAddress >> 1, data);
+#endif
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Advanced function to read a configuration data block.
+bool BatteryGaugeBq27441::advancedGetConfig(uint8_t subClassId, int32_t offset, int32_t length, char * pData)
+{
+ bool success = false;
+
+ if (gReady && (gpI2c != NULL) && (pData != NULL)) {
+ gpI2c->lock();
+ // Read the extended configuration data
+ success = readExtendedData(subClassId, offset, length, pData);
+#ifdef DEBUG_BQ27441
+ if (success) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): read extended data with subClassId %d from offset %d.\n", gAddress >> 1, subClassId, offset);
+ }
+#endif
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Advanced function to write a configuration data block.
+bool BatteryGaugeBq27441::advancedSetConfig(uint8_t subClassId, int32_t offset, int32_t length, const char * pData)
+{
+ bool success = false;
+
+ if (gReady && (gpI2c != NULL) && (pData != NULL)) {
+ gpI2c->lock();
+ // Write the extended configuration data
+ success = writeExtendedData(subClassId, offset, length, pData);
+#ifdef DEBUG_BQ27441
+ if (success) {
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): written %d byte(s) of extended data with subClassId %d from offset %d.\n", gAddress >> 1, length, subClassId, offset);
+ }
+#endif
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Send a control word.
+bool BatteryGaugeBq27441::advancedSendControlWord (uint16_t controlWord, uint16_t *pDataReturned)
+{
+ bool success = false;
+ char data[3];
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Send the control command
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = (char) controlWord; // First byte of controlWord
+ data[2] = (char) (controlWord >> 8); // Second byte of controlWord
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ // Read the two bytes returned if requested
+ if (pDataReturned != NULL) {
+ if (getTwoBytes(0, pDataReturned)) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): sent control word 0x%04x, read back 0x%04x.\n", gAddress >> 1, controlWord, *pDataReturned);
+#endif
+ }
+ } else {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): sent control word 0x%04x.\n", gAddress >> 1, controlWord);
+#endif
+ }
+ }
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Read two bytes starting at a given address on the chip.
+bool BatteryGaugeBq27441::advancedGet (uint8_t address, uint16_t *pDataReturned)
+{
+ bool success = false;
+ uint16_t value;
+
+ if (gReady && (gpI2c != NULL)) {
+ // Make sure there's a recent reading, as most
+ // of these commands involve the chip having done one
+ if (gGaugeOn || makeAdcReading()) {
+ gpI2c->lock();
+ // Read the data
+ if (getTwoBytes(address, &value)) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): read 0x%04x from addresses 0x%02x and 0x%02x.\n", gAddress >> 1, value, address, address + 1);
+#endif
+ if (pDataReturned != NULL) {
+ *pDataReturned = value;
+ }
+ }
+ gpI2c->unlock();
+ }
+ }
+
+ return success;
+}
+
+/// Check if the chip is SEALED or UNSEALED.
+bool BatteryGaugeBq27441::advancedIsSealed()
+{
+ bool sealed = false;
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Check for sealedness
+ sealed = isSealed();
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn) {
+ setHibernate();
+ }
+
+ gpI2c->unlock();
+ }
+
+ return sealed;
+}
+
+/// Put the chip into SEALED mode.
+bool BatteryGaugeBq27441::advancedSeal()
+{
+ bool success = false;
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Seal
+ success = seal();
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Unseal the device.
+bool BatteryGaugeBq27441::advancedUnseal(uint16_t sealCode)
+{
+ bool success = false;
+ char updateStatus;
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+ // Unseal and read the Update Status value
+ if (unseal(sealCode) && readExtendedData(82, 2, 1, &updateStatus)) {
+ // If the update status value has the top bit set then the chip will
+ // reseal itself on the next reset, so this bit needs to be cleared to
+ // unseal it properly
+ if ((updateStatus & (1 << 7)) != 0) {
+ updateStatus &= ~(1 << 7);
+ success = writeExtendedData(82, 2, 1, &updateStatus);
+ } else {
+ success = true;
+ }
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+/// Do a hard reset of the chip.
+bool BatteryGaugeBq27441::advancedReset(void)
+{
+ bool success = false;
+ bool wasSealed;
+ char data[3];
+
+ if (gReady && (gpI2c != NULL)) {
+ gpI2c->lock();
+
+ // Handle unsealing, as this command only works when unsealed
+ wasSealed = isSealed();
+ if (!wasSealed || unseal(gSealCode)) {
+ // Send a RESET sub-command
+ data[0] = 0x00; // Set address to first register for control
+ data[1] = 0x41; // First byte of RESET sub-command (0x41)
+ data[2] = 0x00; // Second byte of RESET sub-command (0x00) (register address will auto-increment)
+
+ if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
+ success = true;
+#ifdef DEBUG_BQ27441
+ printf("BatteryGaugeBq27441 (I2C 0x%02x): chip hard reset.\n", gAddress >> 1);
+#endif
+ }
+
+ // Handle re-sealing and fail if we need to re-seal but can't
+ if (wasSealed && !seal()) {
+ success = false;
+ }
+ }
+
+ // Return to sleep if we are allowed to
+ if (!gGaugeOn && !setHibernate()) {
+ success = false;
+ }
+
+ gpI2c->unlock();
+ }
+
+ return success;
+}
+
+// End Of File