First Post

2025.01.05

1 min to read

English / Deutsch

Hello World! I’m currently working on making a linear voice coil actuator. See the following equation for the maximum flux density:

$$ \begin{equation} B_\text{Max} = \mu_0 \cdot \mu_r \cdot U \cdot b^2 \cdot \frac{1}{4\rho_K \cdot h \cdot d} \end{equation} $$

An image of the perfect coil with absolutely no imperfections, especially not on the left side:

Eine Spule

I’ve also been coding to read a hall sensors values. For initialization:

void hall_init()
{
    adc_oneshot_unit_init_cfg_t init_config1 = {
        .unit_id = ADC_UNIT_1,
        .ulp_mode = ADC_ULP_MODE_DISABLE,
    };
    ESP_ERROR_CHECK(adc_oneshot_new_unit(&init_config1, &adc1_handle));
    adc_oneshot_chan_cfg_t config = {
        .atten = ADC_ATTEN_DB_12,
        .bitwidth = ADC_BITWIDTH_DEFAULT, // 12 Bit
    };
    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc1_handle, ADC_CHANNEL_6, &config));
}

For reading and conversion:

double hall_read() {
    int raw;
    ESP_ERROR_CHECK(adc_oneshot_read(adc1_handle, ADC_CHANNEL_6, &raw));
    double vout = raw / 4096.0 * 3.551859099804305;
    return vout;
}