qenc-readout

Open a quadrature encoder on E1M_QENC0 and poll the position counter. Demonstrates the encoder mode of <alp/counter.h>.

Source: examples/qenc-readout/.

board.yaml

schema_version: 2

som:
  sku: E1M-AEN701

carrier:
  name: E1M-EVK

cores:
  m55_hp:
    os: zephyr
    app: ./src
    peripherals: [counter]

diagnostics:
  log_level: info

Source (abbreviated)

#include <alp/counter.h>
#include <alp/e1m_pinout.h>

int main(void) {
    alp_qenc_t *qenc = alp_qenc_open(&(alp_qenc_config_t){
        .channel_id = E1M_QENC0,
    });
    if (qenc == NULL) {
        printk("[qenc] open failed: err=%d\n", (int)alp_last_error());
        return -1;
    }

    for (int i = 0; i < 20; i++) {
        int32_t position;
        alp_qenc_read(qenc, &position);
        printk("[qenc] position=%d\n", position);
        k_msleep(250);
    }
    alp_qenc_close(qenc);
    return 0;
}

V2N family

On E1M-X V2N the four quadrature encoders are owned by the on-module GD32G553 supervisor. The host driver routes alp_qenc_* through <alp/chips/gd32g553.h>; the example works unchanged because the wrapper hides the transport.

See also

• <alp/counter.h> reference
• Examples overview