MAX1704x help needed

[Max-LAB]

Hi all,

I am trying for my project to use max1704x.h library, and this example in here https://github.com/UncleRus/esp-idf-lib/blob/master/examples/max1704x/default/main/main.c. The Problem is that I am using Adafruit ESP32 S3 Feather board that have already integrated MAX17048 chip.

After an initialisation, board just freez

    ESP_ERROR_CHECK(i2cdev_init());
    esp_err_t r;
    max1704x_t dev = {0 };
    max1704x_config_t config = { 0 };
    max1704x_status_t status = { 0 };
    uint16_t version = 0;
    float voltage = 0;
    float soc_percent = 0;
    float rate_change = 0;
    
    /**
     * Set up I2C bus to communicate with MAX1704X
     */

    dev.model = MAX17048_9;
    ESP_ERROR_CHECK(max1704x_init_desc(&dev, 0, 18, 19)); // SDA 18, SCL 19 for S3
    ESP_ERROR_CHECK_WITHOUT_ABORT(max1704x_get_config(&dev)); // when I comment this line it works

As described in the example above for ESP-32 S3 boards SDA is 18 and SCL is 19, but in this case, on Adafruit with integrated MAX17048 chip I am not sure.

Does anyone have a clue what could be a problem and did anyone tried to test this on Feather board?

[UncleRus]

@shuki25 Please comment

[shuki25]

I reviewed the pinout for your board and the pinout for SCL is 4 and SDA is 3.

[shuki25]

Also, I was looking at the Adafruit website, and it appears that previous board versions had an older battery management IC. Can you confirm that your board is equipped with the latest version featuring the MAX1704X chip?

If so, did you run menuconfig? There's a setting in there that you have to specify which chipset you are using.

Component config > MAX1704X Battery Fuel Gauge > Chip type

I reviewed the schematic of the board, it's still showing that SDA is 3 and SCL is 4. So if your code says it could not read from device 0x36, it probably means that the device isn't there on the I2C bus line.

I would suggest you to use ESP-IDF example code to scan all devices on the i2c bus line to see what devices you have connected on the board.

ESP-IDF example code for i2c_tools

[Max-LAB]

@shuki25 thank you for your reply

Also, I was looking at the Adafruit website, and it appears that previous board versions had an older battery management IC. Can you confirm that your board is equipped with the latest version featuring the MAX1704X chip?

Actually yes, my board is the one with a MAX17048 Monitor label at the back and 7048/1CA6 written on chip on the front like in here ESP32 Feather Pinouts

Here is my original picture

If so, did you run menuconfig? There's a setting in there that you have to specify which chipset you are using.
Component config > MAX1704X Battery Fuel Gauge > Chip type

Actually yes, this also occurred to me

And here is a snippet from sdkconfig file which also confirms that

Would posting the entire sdkconfig file be beneficial?

I would suggest you to use ESP-IDF example code to scan all devices on the i2c bus line to see what devices you have connected on the board.

Aaand here is the culprit, nothing is found on i2c bus line :(

The Qeustion is how to enable it or wake it up? Do I need a pullup resistor between SDA and +3.3V and also SCL and +3.3V? Nothing is mentioned in here MAX1708 Battery Monitor

[Max-LAB]

@shuki25

Small progress, on i2c-tools test above wrong SDA and SCL were selected. When I changed them to SDA 3 and SCL 4 scan started but unfortunately, nothing was found. Here is a code and picture

cmd_i2ctools.c

static const char *TAG = "cmd_i2ctools";

#if CONFIG_IDF_TARGET_ESP32S3 || CONFIG_IDF_TARGET_ESP32H2
static gpio_num_t i2c_gpio_sda = 3; #<-- correct SDA
static gpio_num_t i2c_gpio_scl = 4; #<-- correct SCL
#elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32C2
static gpio_num_t i2c_gpio_sda = 5;
static gpio_num_t i2c_gpio_scl = 6;
#else
static gpio_num_t i2c_gpio_sda = 18;
static gpio_num_t i2c_gpio_scl = 19;
#endif

static uint32_t i2c_frequency = 100000;
static i2c_port_t i2c_port = I2C_NUM_0;

[Max-LAB]

@shuki25 Finally, I managed to get it to work on my Adafruit ESP32 S3 Feather board :)

In the end problem was the pullup resistors between SDA - 3V and SCL - 3V. Also, the last comment in this thread helped me. Esp32 IDF release/5.0 running on ESP32S3 Feather I2C problem. For this implementation I used 3k resistors.

It is not the best and most beautiful implementation, but for the test it was sufficient.

i2c-tools detected it immediately. SDA 3 - SCl 4

And here is an output from your library :)

Thank you both @shuki25 and @UncleRus again for the quick responses and help you provided.

[shuki25]

That's great to hear that you figured it out. Seems like the 10K pull-up resistors was too high for i2c bus line in the original schematic design.

Read the following article, useful information about this.

i2c pull-up resistance calculation article

[Max-LAB]

Hi @shuki25, hi @UncleRus I have one additional not directly related question to an upper problem. For my project, I want to determine the entire power consumption of my sensor network. My question is, can I rely on SOC and Voltage parameters received and collected from every node during some period of time?

Clearly, i can see voltage and SOC percentage drop during some period of time, and plot it inside a graph but can this be a good indicator of how much power my sensor network is using during runtime?

My test scenario is 5 nodes scattered throughout a closed space. I did 3 measurements with all nodes in the same places, the same code deployed on every one of them, the same antenna orientation, and closely the same battery SOC at the beginning of the measurement. In all three times, I got almost the same values with 0,01750 Voltage and 0,34766 SOC percentage difference at the end.

[shuki25]

As far as what I already know from different sources is that the IC chip's operation involves the calculation of the State of Charge (SOC) value over time. Therefore, repeatedly resetting the MAX1704x chip may lead to reduced accuracy, as it continuously monitors charging and battery usage over an extended period.