groundwork for BMS

include/i2c.h

@@ -0,0 +1,26 @@
+#ifndef I2C_HELPER_H
+#define I2C_HELPER_H
+#include "driver/gpio.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// I2C Configuration (Match your schematic)
+#define I2C_MASTER_SCL_IO           GPIO_NUM_23   // Example GPIO for C6
+#define I2C_MASTER_SDA_IO           GPIO_NUM_22  // Example GPIO for C6
+#define I2C_MASTER_NUM              0
+#define I2C_MASTER_FREQ_HZ          100000        // use standard freq 
+#define I2C_MASTER_TIMEOUT_MS       1000
+
+esp_err_t i2c_init();
+esp_err_t max17048_read_reg(uint8_t reg_addr, uint8_t *MSB, uint8_t *LSB);
+esp_err_t max17048_write_reg(uint8_t reg_addr, uint8_t MSB, uint8_t LSB);
+esp_err_t max17048_friendly_write_reg(uint8_t reg_addr, uint8_t MSB, uint8_t LSB,
+                                      uint8_t MSBmask, uint8_t LSBmask);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

include/max17048.h

@@ -0,0 +1,38 @@
+#ifndef MAX_17_H
+#define MAX_17_H
+
+#define MAX17048_ADDR           0x36
+#define MAX17048_REG_VCELL      0x02 // Voltage
+#define MAX17048_REG_SOC        0x04 // State of Charge (%)
+#define MAX17048_REG_MODE       0x06
+#define MAX17048_REG_VERSION    0x08
+#define MAX17048_REG_CONFIG     0x0C
+#define MAX17048_REG_CMD        0xFE // Command (Reset)
+#define MAX17048_REG_STATUS     0x1A
+#define MAX17048_REG_VALRT      0x14
+#define MAX17048_REG_VRST_ID    0x18
+
+// Commands
+#define MAX17048_CMD_POR        0x5400 // Power On Reset command
+#define MAX17048_CMD_QSTRT      0x4000 // Quick Start command
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+#include "driver/i2c.h"
+
+esp_err_t max17048_init();
+uint8_t bms_get_soc();
+esp_err_t bms_set_alert_bound_voltages(float min, float max);
+esp_err_t bms_set_reset_voltage(float vreset);
+esp_err_t bms_clear_status();
+
+#define bms_set_alsc() max17048_friendly_write_reg(MAX17048_REG_CONFIG, 0, 1<<6, 0, 1<<6)
+#define bms_clear_status() max17048_write_reg(MAX17048_REG_STATUS, 0, 0)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

sdkconfig.seeed_xiao_esp32c6

@@ -132,7 +132,6 @@ CONFIG_SOC_GPIO_DEEP_SLEEP_WAKE_VALID_GPIO_MASK=0
 CONFIG_SOC_GPIO_DEEP_SLEEP_WAKE_SUPPORTED_PIN_CNT=8
 CONFIG_SOC_GPIO_VALID_DIGITAL_IO_PAD_MASK=0x000000007FFFFF00
 CONFIG_SOC_GPIO_SUPPORT_FORCE_HOLD=y
-CONFIG_SOC_GPIO_SUPPORT_HOLD_IO_IN_DSLP=y
 CONFIG_SOC_GPIO_SUPPORT_HOLD_SINGLE_IO_IN_DSLP=y
 CONFIG_SOC_GPIO_CLOCKOUT_BY_GPIO_MATRIX=y
 CONFIG_SOC_CLOCKOUT_HAS_SOURCE_GATE=y
@@ -2357,13 +2356,6 @@ CONFIG_LIBC_TIME_SYSCALL_USE_RTC_HRT=y
 #
 # CONFIG_OPENTHREAD_ENABLED is not set
 
-#
-# Thread Console
-#
-CONFIG_OPENTHREAD_CLI=y
-CONFIG_OPENTHREAD_CONSOLE_COMMAND_PREFIX="ot"
-# end of Thread Console
-
 #
 # OpenThread Spinel
 #

src/BLE.cpp

@@ -2,7 +2,6 @@
 #include "freertos/queue.h"
 #include "freertos/task.h"
 #include "BLE.hpp"
-#include "NimBLEDevice.h"
 #include "WiFi.hpp"
 #include "nvs_flash.h"
 #include "socketIO.hpp"

src/CMakeLists.txt

@@ -1,7 +1,7 @@
 # This file was automatically generated for projects
 # without default 'CMakeLists.txt' file.
 
-FILE(GLOB_RECURSE app_sources ${CMAKE_SOURCE_DIR}/src/*.* ${CMAKE_SOURCE_DIR}/include/*.cpp)
+FILE(GLOB_RECURSE app_sources ${CMAKE_SOURCE_DIR}/src/*.*)
 
 idf_component_register(SRCS ${app_sources}
                     INCLUDE_DIRS "."

src/batteryManagement.cpp

@@ -0,0 +1,10 @@
+
+    // 3. Post Event to System Loop
+    battery_data_t data = { .soc = soc, .voltage = voltage };
+    
+    esp_event_post(BATTERY_EVENTS, BATTERY_EVENT_UPDATE, &data, sizeof(data), 0);
+    
+    // Optional: Post warnings
+    if (soc < 20.0) {
+      esp_event_post(BATTERY_EVENTS, BATTERY_EVENT_LOW, NULL, 0, 0);
+    }

src/i2c.c

@@ -0,0 +1,75 @@
+#include "i2c.h"
+#include "driver/i2c.h"
+#include "esp_log.h"
+#include "max17048.h"
+
+// Helper: Initializes I2C controller at 100kHz, returns 0=success
+esp_err_t i2c_init() {
+  // 1. Initialize I2C
+  i2c_config_t conf = {
+    .mode = I2C_MODE_MASTER,
+    .sda_io_num = I2C_MASTER_SDA_IO,
+    .scl_io_num = I2C_MASTER_SCL_IO,
+    .sda_pullup_en = GPIO_PULLUP_ENABLE,
+    .scl_pullup_en = GPIO_PULLUP_ENABLE,
+    .master.clk_speed = I2C_MASTER_FREQ_HZ,
+  };
+
+  return (i2c_param_config(I2C_MASTER_NUM, &conf) || 
+  i2c_driver_install(I2C_MASTER_NUM, conf.mode, 0, 0, 0));
+}
+
+// Helper: Read 16-bit register to 2-byte array (MSB first big endian)
+esp_err_t max17048_read_reg(uint8_t reg_addr, uint8_t *MSB, uint8_t *LSB) {  
+  // this is better than converting to little endian for my application
+  // since I usually need to handle bytes individually.
+  uint8_t data[2];
+  // Write register address
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, (MAX17048_ADDR << 1) | I2C_MASTER_WRITE, true);
+  i2c_master_write_byte(cmd, reg_addr, true);
+  
+  // Restart and Read 2 bytes
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, (MAX17048_ADDR << 1) | I2C_MASTER_READ, true);
+  i2c_master_read(cmd, data, 2, I2C_MASTER_LAST_NACK);
+  i2c_master_stop(cmd);
+  
+  esp_err_t ret = i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, pdMS_TO_TICKS(I2C_MASTER_TIMEOUT_MS));
+  i2c_cmd_link_delete(cmd);
+
+  if (ret == ESP_OK) {
+    *MSB = data[0];
+    *LSB = data[1];
+  }
+
+  return ret;
+}
+
+// Write big endian 2-byte array to a 16-bit register
+esp_err_t max17048_write_reg(uint8_t reg_addr, uint8_t MSB, uint8_t LSB) {
+  // Write register address
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, (MAX17048_ADDR << 1) | I2C_MASTER_WRITE, true);
+  i2c_master_write_byte(cmd, reg_addr, true);
+  i2c_master_write_byte(cmd, MSB, true);
+  i2c_master_write_byte(cmd, LSB, true);
+  i2c_master_stop(cmd);
+  
+  esp_err_t ret = i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, pdMS_TO_TICKS(I2C_MASTER_TIMEOUT_MS));
+  i2c_cmd_link_delete(cmd);
+  return ret;
+}
+
+esp_err_t max17048_friendly_write_reg(uint8_t reg_addr, uint8_t MSB, uint8_t LSB,
+  uint8_t MSBmask, uint8_t LSBmask) {
+  uint8_t origMSB, origLSB;
+  esp_err_t err = max17048_read_reg(reg_addr, origMSB, origLSB);
+  MSB &= MSBmask;
+  LSB &= LSBmask;
+  MSB |= origMSB & ~MSBmask;
+  LSB |= origLSB & ~LSBmask;
+  return err | max17048_write_reg(reg_addr, MSB, LSB);
+}

src/max17048.c

@@ -0,0 +1,44 @@
+#include "max17048.h"
+#include "esp_err.h"
+#include "i2c.h"
+#include "esp_timer.h"
+
+static const char *TAG = "BATTERY";
+uint8_t established_soc;
+
+esp_err_t max17048_init() {
+  esp_err_t err = ESP_OK;
+  uint8_t status, _;
+  err |= i2c_init();
+  err |= max17048_read_reg(MAX17048_REG_STATUS, &status, &_);
+  err |= bms_set_alert_bound_voltages(3.3, 4.2);
+  err |= bms_set_reset_voltage(3.25);
+  err |= bms_set_alsc();
+  err |= bms_clear_status();
+
+}
+
+// Helper: Function reading MAX17048 SOC register, returning battery percentage
+uint8_t bms_get_soc() {
+  // uint16_t raw_soc, raw_vcell;
+  uint16_t raw_soc;
+
+  // Read SOC (Register 0x04)
+  if (max17048_read_reg(MAX17048_REG_SOC, ((uint8_t*)&raw_soc)+1, (uint8_t*)&raw_soc) == ESP_OK) {
+    return (raw_soc >> 8) + raw_soc & 0x80; // round to the nearest percent
+  } else {
+    ESP_LOGE(TAG, "Failed to read MAX17048");
+    return 0;
+  }
+}
+
+esp_err_t bms_set_alert_bound_voltages(float min, float max) {
+  uint8_t minVal = (uint16_t)((float)min * 1000.0) / 20;
+  uint8_t maxVal = (uint16_t)((float)max * 1000.0) / 20;
+  return max17048_write_reg(MAX17048_REG_VALRT, minVal, maxVal);
+}
+
+esp_err_t bms_set_reset_voltage(float vreset) {
+  uint8_t maxVal = (uint16_t)((float)vreset * 1000.0) / 40;
+  max17048_write_reg(MAX17048_REG_VRST_ID, vreset, 0);
+}