initial WIP

lots of code copied over, things filled in to hopefully get the LED matrix lighting up. untested.

firmware/app/driver/accel.c

@@ -0,0 +1,168 @@
+/*
+ * accel.c
+ *
+ *  Created on: Oct 13, 2024
+ *      Author: true
+ */
+
+#include "ch32x035_conf.h"
+
+#include "accel.h"
+#include "lis2hh12_reg.h"
+
+#include "comms/spi_master.h"
+
+#include "misc/i8atan2.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+
+
+// user data
+AccelData accel;
+
+uint8_t accel_found = 0;
+
+uint8_t movement_idx;       // index into "read" register
+int16_t movement_read[4];   // last read movement value
+int16_t movement;           // last calculated movement value
+uint16_t movement_worst;    // worst seen movement value
+
+
+// hardware
+static stmdev_ctx_t dev_ctx;
+
+
+
+static int32_t accel_write(void *handle, uint8_t reg, const uint8_t *bufp, uint16_t len)
+{
+    (void)(handle);
+
+    // i2c_write_reg8(LIS2_I2C_ADDR_SDO_LOW, reg, bufp, len);
+    LIS2_CS_PORT->BCR = LIS2_CS_PIN;
+    spim_write_reg8(reg, bufp, len);
+    LIS2_CS_PORT->BSHR = LIS2_CS_PIN;
+
+    return 0;
+}
+
+static int32_t accel_read(void *handle, uint8_t reg, uint8_t *bufp, uint16_t len)
+{
+    (void)(handle);
+
+    // i2c_read_reg8(LIS2DW_I2C_ADDR_SDO_LOW, reg, bufp, len);
+    LIS2_CS_PORT->BCR = LIS2_CS_PIN;
+    spim_read_reg8(reg, bufp, len);
+    LIS2_CS_PORT->BSHR = LIS2_CS_PIN;
+
+    return 0;
+}
+
+
+void accel_init()
+{
+    uint8_t devid;
+    uint8_t reset;
+    uint16_t timeout = 1000;
+
+    dev_ctx.write_reg = accel_write;
+    dev_ctx.read_reg = accel_read;
+
+    // make sure we've got the right device
+    lis2hh12_dev_id_get(&dev_ctx, &devid);
+    if (devid == LIS2HH12_ID) {
+        accel_found = 1;
+    }
+
+    // reset accelerometer
+    if (accel_found) {
+        lis2hh12_dev_reset_set(&dev_ctx, PROPERTY_ENABLE);
+        do {
+            lis2hh12_dev_reset_get(&dev_ctx, &reset);
+            if (!reset) {
+                timeout = 0;
+                accel_found = 1;
+            }
+        } while (timeout--);
+    }
+
+    if (accel_found) {
+        // disable block update
+        // data in output registers is updated immediately; FIFO is disabled
+        lis2hh12_block_data_update_set(&dev_ctx, PROPERTY_DISABLE);
+
+        // configure scale, power mode
+        lis2hh12_xl_full_scale_set(&dev_ctx, LIS2HH12_2g);
+        // TODO: check this
+        // lis2hh12_power_mode_set(&dev_ctx, LIS2DW12_CONT_LOW_PWR_LOW_NOISE_4);
+
+        // configure filter chain
+        // low pass filter enabled for 6D (not currently used)
+        lis2hh12_xl_filter_out_path_set(&dev_ctx, LIS2HH12_FILT_LP);
+        // digital LPF2 filter of output data
+        lis2hh12_xl_filter_low_bandwidth_set(&dev_ctx, LIS2HH12_LP_ODR_DIV_9);
+
+        // configure output data rate
+        lis2hh12_xl_data_rate_set(&dev_ctx, LIS2HH12_XL_ODR_200Hz);
+    }
+}
+
+void accel_poll()
+{
+    uint8_t reg = 1;
+    int16_t xyz[3];
+
+    if (!accel_found) return;
+
+    while (reg) {
+        // read output only if new value is available
+        lis2hh12_xl_flag_data_ready_get(&dev_ctx, &reg);
+
+        if (reg) {
+            // read acceleration data
+            memset(xyz, 0x00, 3 * sizeof(int16_t));
+            lis2hh12_acceleration_raw_get(&dev_ctx, xyz);
+
+            accel.x = xyz[0] >>= 8;
+            accel.y = xyz[1] >>= 8;
+            accel.z = xyz[2] >>= 8;
+
+            // compute our shitty "movement" thing
+            // awful way to detect being still
+            reg = sizeof(movement_read) / sizeof(movement_read[0]);
+
+            movement_idx++;
+            if (movement_idx == reg) {
+                movement_idx = 0;
+                movement = abs(movement_read[3] - movement_read[0]);
+                if (movement > movement_worst) {
+                    movement_worst = movement;
+                }
+            }
+
+            movement_read[movement_idx] = abs(accel.x) + abs(accel.y);
+        }
+    }
+}
+
+int8_t accel_get_rotation(struct AccelData *a)
+{
+    int8_t nx, ny, ret;
+
+    nx = -a->x;
+    ny =  a->y;
+
+    ret = i8atan2(nx, ny) >> 1;
+    if (ret < 0) {
+        ret += 128;
+    }
+
+    return ret;
+}
+
+int16_t accel_get_movement()
+{
+    return movement;
+}