To use this library you must to provide functions for both reading and writing the I2C bus. Function definitions must be the following.
int32_t i2c_read(void *handle, uint8_t address, uint8_t reg, uint8_t *buffer, uint16_t size);
int32_t i2c_write(void *handle, uint8_t address, uint8_t reg, const uint8_t *buffer, uint16_t size);Where address is the I2C address, reg is the register to read or write, buffer holds the data to write or read into and size is the amount of data to read or write. The handle parameter is an optional customizable argument. You can use it if your I2C implementation requires any additional information such has number of the hardware I2C driver. For example implementation see ESP I2C helper. For working demo see M5StickC kitchen sink.
With platforms such as ESP-IDF you can use menuconfig and a single call to axp192_init() to configure the chip. When configuring pay attention to which power rails are enabled and what voltage they are configured to.
Pay especially attention to DCDC1 which is usually used for powering the MCU. Your program disabling the power from the MCU upon boot basically bricks the board. Reviving the board from this situation is possible but might be difficult.
$ make menuconfig
#include "axp192.h"
#include "user_i2c.h"
axp192_t axp;
/* Add pointers to the glue functions. */
axp.read = &user_i2c_read;
axp.write = &user_i2c_write;
/* You could set the handle here. It can be pointer to anything. */
axp.handle = NULL;
axp192_init(&axp);If your system does not use menuconfig you cannot use axp192_init(). Instead configure the chip manually with the needed calls to axp192_ioctl() function. Again pay attention when configuring the power rails. You do not want to shut down the MCU.
#include "axp192.h"
#include "user_i2c.h"
axp192_t axp;
/* Add pointers to HAL functions. */
axp.read = &user_i2c_read;
axp.write = &user_i2c_write;
/* You could set the handle here. It can be pointer to anything. */
axp.handle = NULL;
/* Be careful when setting voltages not to brick your board. */
axp192_ioctl(&axp, AXP192_DCDC1_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_DCDC2_SET_VOLTAGE, 2275);
axp192_ioctl(&axp, AXP192_DCDC3_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDOIO0_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDO2_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDO3_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_DCDC1_ENABLE);
axp192_ioctl(&axp, AXP192_DCDC2_ENABLE);
axp192_ioctl(&axp, AXP192_DCDC3_ENABLE);
axp192_ioctl(&axp, AXP192_LDOIO0_ENABLE);
axp192_ioctl(&axp, AXP192_LDO2_ENABLE);
axp192_ioctl(&axp, AXP192_LDO3_ENABLE);
axp192_ioctl(&axp, AXP192_EXTEN_ENABLE);
axp192_ioctl(&axp, AXP192_COULOMB_COUNTER_ENABLE);Use axp192_read() to read the values of the registers. All the
ADC registers will be read as floats. All other registers will be treated as raw bytes.
See axp192.h or datasheet for all possible registers and how to intepret the values.
float vacin, iacin, vvbus, ivbus, temp, pbat, vbat, icharge, idischarge, vaps, cbat;
/* All ADC registers will be read as floats. */
axp192_read(&axp, AXP192_ACIN_VOLTAGE, &vacin);
axp192_read(&axp, AXP192_ACIN_CURRENT, &iacin);
axp192_read(&axp, AXP192_VBUS_VOLTAGE, &vvbus);
axp192_read(&axp, AXP192_VBUS_CURRENT, &ivbus);
axp192_read(&axp, AXP192_TEMP, &temp);
axp192_read(&axp, AXP192_TS_INPUT, &vts);
axp192_read(&axp, AXP192_BATTERY_POWER, &pbat);
axp192_read(&axp, AXP192_BATTERY_VOLTAGE, &vbat);
axp192_read(&axp, AXP192_CHARGE_CURRENT, &icharge);
axp192_read(&axp, AXP192_DISCHARGE_CURRENT, &idischarge);
axp192_read(&axp, AXP192_APS_VOLTAGE, &vaps);
axp192_read(&axp, AXP192_COULOMB_COUNTER, &cbat);
printf(
"vacin: %.2fV iacin: %.2fA vvbus: %.2fV ivbus: %.2fA vts: %.2fV temp: %.0fC "
"pbat: %.2fmW vbat: %.2fV icharge: %.2fA idischarge: %.2fA, vaps: %.2fV cbat: %.2fmAh",
vacin, iacin, vvbus, ivbus, vts, temp, pbat, vbat, icharge, idischarge, vaps, cbat
);uint8_t power, charge;
/* All non ADC registers will be read as a raw bytes. */
axp192_read(&axp, AXP192_POWER_STATUS, &power);
axp192_read(&axp, AXP192_CHARGE_STATUS, &charge);
printf("power: 0x%02x charge: 0x%02x", power, charge);You can use axp192_write() to write a single raw byte directly to a register.
uint8_t buffer = 0xde;
axp192_write(&axp, AXP192_DATA_BUFFER0, &buffer);However common configuration tasks are also provided as an axp192_ioctl() call.
axp192_ioctl(&axp, AXP192_DCDC1_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_DCDC2_SET_VOLTAGE, 2275);
axp192_ioctl(&axp, AXP192_DCDC3_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDOIO0_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDO2_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_LDO3_SET_VOLTAGE, 3300);
axp192_ioctl(&axp, AXP192_EXTEN_ENABLE);
axp192_ioctl(&axp, AXP192_EXTEN_DISABLE);
axp192_ioctl(&axp, AXP192_LDOIO0_ENABLE);
axp192_ioctl(&axp, AXP192_LDOIO0_DISABLE);
axp192_ioctl(&axp, AXP192_LDO2_ENABLE);
axp192_ioctl(&axp, AXP192_LDO2_DISABLE);
axp192_ioctl(&axp, AXP192_LDO3_ENABLE);
axp192_ioctl(&axp, AXP192_LDO3_DISABLE);
/* Do not disable DCDC1 unless you know what you are doing. */
axp192_ioctl(&axp, AXP192_DCDC1_ENABLE);
axp192_ioctl(&axp, AXP192_DCDC1_DISABLE);
axp192_ioctl(&axp, AXP192_DCDC2_ENABLE);
axp192_ioctl(&axp, AXP192_DCDC2_DISABLE);
axp192_ioctl(&axp, AXP192_DCDC3_ENABLE);
axp192_ioctl(&axp, AXP192_DCDC3_DISABLE);
axp192_ioctl(&axp, AXP192_GPIO0_SET_LEVEL, AXP192_HIGH);
axp192_ioctl(&axp, AXP192_GPIO0_SET_LEVEL, AXP192_LOW);
axp192_ioctl(&axp, AXP192_GPIO1_SET_LEVEL, AXP192_HIGH);
axp192_ioctl(&axp, AXP192_GPIO1_SET_LEVEL, AXP192_LOW);
axp192_ioctl(&axp, AXP192_GPIO2_SET_LEVEL, AXP192_HIGH);
axp192_ioctl(&axp, AXP192_GPIO2_SET_LEVEL, AXP192_LOW);
axp192_ioctl(&axp, AXP192_GPIO4_SET_LEVEL, AXP192_HIGH);
axp192_ioctl(&axp, AXP192_GPIO4_SET_LEVEL, AXP192_LOW);| Output | Type | Example usage | Voltage | Amperage |
|---|---|---|---|---|
| DCDC1 | Buck | 3.3V IO | 0v7-3v5 | 1200mA |
| DCDC2 | Buck | 1.25Vcore | 0v7-2v275 | 1600mA |
| DCDC3 | Buck | 2.5Vddr | 0v7-3v5 | 700mA |
| LDO1 | LDO | RTC | 3v3 | 30mA |
| LDO2 | LDO | Analog/FM | 1v8-3v3 | 200mA |
| LDO3 | LDO | 1.8V HDMI | 1v8-3v3 | 200mA |
| LDOIO0 | LDO | Vmic | 1v8-3v3 | 50mA |
LDO1 cannot be configured and it is always on.
| Output | M5StickC | M5Core2 |
|---|---|---|
| DCDC1 | VESP_3V3 | MCU_VDD |
| DCDC2 | ||
| DCDC3 | LCD_BL | |
| LDO1 | RTC_VCC | RTC_VDD |
| LDO2 | LCD_BL_VCC | PERI_VDD |
| LDO3 | LCD_LOGIC_VCC | VIB_MOTOR |
| LDOIO0 | MIC_VCC | BUS_PW_EN |
| IO1 | SYS_LED | |
| IO2 | SPK_EN | |
| IO3 | ||
| IO4 | LCD_RST |