adxl345: Add support for adxl345 accelerometer

Add support for taking measurements from an adxl345 accelerometer via
SPI interface.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/example-extras.cfg

@@ -556,6 +556,32 @@
 #   measurements, e.g. with an accelerometer.
 #   Default value is 0.1 which is a good all-round value for most printers.
 
+# Support for ADXL345 accelerometers. This support allows one to query
+# accelerometer measurements from the sensor. This enables an
+# ACCELEROMETER_MEASURE command (see docs/G-Codes.md for more
+# information). The default chip name is "default", but one may
+# specify an explicit name (eg, [adxl345 my_chip_name]).
+#[adxl345]
+#axes_map: x,y,z
+#   The accelerometer axis for each of the printer's x, y, and z axes.
+#   This may be useful if the accelerometer is mounted in an
+#   orientation that does not match the printer orientation. For
+#   example, one could set this to "y,x,z" to swap the x and y axes.
+#   It is also possible to negate an axis if the accelerometer
+#   direction is reversed (eg, "x,z,-y"). The default is "x,y,z".
+#cs_pin:
+#   The SPI enable pin for the sensor. This parameter must be
+#   provided.
+#spi_speed: 5000000
+#   The SPI speed (in hz) to use when communicating with the chip.
+#   The default is 5000000.
+#spi_bus:
+#spi_software_sclk_pin:
+#spi_software_mosi_pin:
+#spi_software_miso_pin:
+#   These optional parameters allow one to customize the SPI settings
+#   used to communicate with the chip.
+
 
 ######################################################################
 # Config file helpers

docs/G-Codes.md

@@ -633,3 +633,17 @@ section is enabled:
   [target=<target_temperature>]`: Sets the target temperature for a
   temperature_fan. If a target is not supplied, it is set to the
   specified temperature in the config file.
+
+## Adxl345 Accelerometer Commands
+
+The following command is available when an "adxl345" config section is
+enabled:
+- `ACCELEROMETER_MEASURE [CHIP=<config_name>] [RATE=<value>]
+  [NAME=<value>]`: Starts accelerometer measurements at the requested
+  number of samples per second. If CHIP is not specified it defaults
+  to "default". Valid rates are 25, 50, 100, 200, 400, 800, 1600,
+  and 3200. If RATE is zero (or not specified) then the current series
+  of measurements are stopped and the results are written to a file
+  named `/tmp/adxl345-<name>.csv` where "<name>" is the optional NAME
+  parameter. If NAME is not specified it defaults to the current time
+  in "YYYYMMDD_HHMMSS" format.

klippy/extras/adxl345.py

@@ -0,0 +1,225 @@
+# Support for reading acceleration data from an adxl345 chip
+#
+# Copyright (C) 2020  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging, time, collections
+from . import bus
+
+# ADXL345 registers
+REG_DEVID = 0x00
+REG_BW_RATE = 0x2C
+REG_POWER_CTL = 0x2D
+REG_DATA_FORMAT = 0x31
+REG_FIFO_CTL = 0x38
+REG_MOD_READ = 0x80
+REG_MOD_MULTI = 0x40
+
+QUERY_RATES = {
+    25: 0x8, 50: 0x9, 100: 0xa, 200: 0xb, 400: 0xc,
+    800: 0xd, 1600: 0xe, 3200: 0xf,
+}
+
+SCALE = 0.004 * 9.80665 * 1000. # 4mg/LSB * Earth gravity in mm/s**2
+
+Accel_Measurement = collections.namedtuple(
+    'Accel_Measurement', ('time', 'accel_x', 'accel_y', 'accel_z'))
+
+# Sample results
+class ADXL345Results:
+    def __init__(self):
+        self.samples = []
+        self.drops = self.overflows = 0
+        self.time_per_sample = self.start_range = self.end_range = 0.
+    def get_samples(self):
+        return self.samples
+    def get_stats(self):
+        return ("drops=%d,overflows=%d"
+                ",time_per_sample=%.9f,start_range=%.6f,end_range=%.6f"
+                % (self.drops, self.overflows,
+                   self.time_per_sample, self.start_range, self.end_range))
+    def setup_data(self, axes_map, raw_samples, end_sequence, overflows,
+                   start1_time, start2_time, end1_time, end2_time):
+        if not raw_samples or not end_sequence:
+            return
+        (x_pos, x_scale), (y_pos, y_scale), (z_pos, z_scale) = axes_map
+        self.overflows = overflows
+        self.start_range = start2_time - start1_time
+        self.end_range = end2_time - end1_time
+        total_count = (end_sequence - 1) * 8 + len(raw_samples[-1][1]) // 6
+        total_time = end2_time - start2_time
+        self.time_per_sample = time_per_sample = total_time / total_count
+        seq_to_time = time_per_sample * 8.
+        self.samples = samples = [None] * total_count
+        actual_count = 0
+        for seq, data in raw_samples:
+            d = bytearray(data)
+            count = len(data)
+            sdata = [(d[i] | (d[i+1] << 8)) - ((d[i+1] & 0x80) << 9)
+                     for i in range(0, count-1, 2)]
+            seq_time = start2_time + seq * seq_to_time
+            for i in range(count//6):
+                samp_time = seq_time + i * time_per_sample
+                x = sdata[i*3 + x_pos] * x_scale
+                y = sdata[i*3 + y_pos] * y_scale
+                z = sdata[i*3 + z_pos] * z_scale
+                samples[actual_count] = Accel_Measurement(samp_time, x, y, z)
+                actual_count += 1
+        del samples[actual_count:]
+        self.drops = total_count - actual_count
+
+# Printer class that controls measurments
+class ADXL345:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.query_rate = 0
+        self.last_tx_time = 0.
+        am = {'x': (0, SCALE), 'y': (1, SCALE), 'z': (2, SCALE),
+              '-x': (0, -SCALE), '-y': (1, -SCALE), '-z': (2, -SCALE)}
+        axes_map = config.get('axes_map', 'x,y,z').split(',')
+        if len(axes_map) != 3 or any([a.strip() not in am for a in axes_map]):
+            raise config.error("Invalid adxl345 axes_map parameter")
+        self.axes_map = [am[a.strip()] for a in axes_map]
+        # Measurement storage (accessed from background thread)
+        self.raw_samples = []
+        self.last_sequence = 0
+        self.samples_start1 = self.samples_start2 = 0.
+        # Setup mcu sensor_adxl345 bulk query code
+        self.spi = bus.MCU_SPI_from_config(config, 3, default_speed=5000000)
+        self.mcu = mcu = self.spi.get_mcu()
+        self.oid = oid = mcu.create_oid()
+        self.query_adxl345_cmd = self.query_adxl345_end_cmd =None
+        mcu.add_config_cmd("config_adxl345 oid=%d spi_oid=%d"
+                           % (oid, self.spi.get_oid()))
+        mcu.add_config_cmd("query_adxl345 oid=%d clock=0 rest_ticks=0"
+                           % (oid,), on_restart=True)
+        mcu.register_config_callback(self._build_config)
+        mcu.register_response(self._handle_adxl345_start, "adxl345_start", oid)
+        mcu.register_response(self._handle_adxl345_data, "adxl345_data", oid)
+        # Register commands
+        name = "default"
+        if len(config.get_name().split()) > 1:
+            name = config.get_name().split()[1]
+        gcode = self.printer.lookup_object('gcode')
+        gcode.register_mux_command("ACCELEROMETER_MEASURE", "CHIP", name,
+                                   self.cmd_ACCELEROMETER_MEASURE,
+                                   desc=self.cmd_ACCELEROMETER_MEASURE_help)
+        if name == "default":
+            gcode.register_mux_command("ACCELEROMETER_MEASURE", "CHIP", None,
+                                       self.cmd_ACCELEROMETER_MEASURE)
+    def _build_config(self):
+        self.query_adxl345_cmd = self.mcu.lookup_command(
+            "query_adxl345 oid=%c clock=%u rest_ticks=%u",
+            cq=self.spi.get_command_queue())
+        self.query_adxl345_end_cmd = self.mcu.lookup_query_command(
+            "query_adxl345 oid=%c clock=%u rest_ticks=%u",
+            "adxl345_end oid=%c end1_time=%u end2_time=%u"
+            " limit_count=%hu sequence=%hu",
+            oid=self.oid, cq=self.spi.get_command_queue())
+    def _clock_to_print_time(self, clock):
+        return self.mcu.clock_to_print_time(self.mcu.clock32_to_clock64(clock))
+    def _handle_adxl345_start(self, params):
+        self.samples_start1 = self._clock_to_print_time(params['start1_time'])
+        self.samples_start2 = self._clock_to_print_time(params['start2_time'])
+    def _handle_adxl345_data(self, params):
+        last_sequence = self.last_sequence
+        sequence = (last_sequence & ~0xffff) | params['sequence']
+        if sequence < last_sequence:
+            sequence += 0x10000
+        self.last_sequence = sequence
+        raw_samples = self.raw_samples
+        if len(raw_samples) >= 200000:
+            # Avoid filling up memory with too many samples
+            return
+        raw_samples.append((sequence, params['data']))
+    def _convert_sequence(self, sequence):
+        sequence = (self.last_sequence & ~0xffff) | sequence
+        if sequence < self.last_sequence:
+            sequence += 0x10000
+        return sequence
+    def start_measurements(self, rate=None):
+        if rate is None:
+            rate = 3200
+        # Verify chip connectivity
+        params = self.spi.spi_transfer([REG_DEVID | REG_MOD_READ, 0x00])
+        response = bytearray(params['response'])
+        if response[1] != 0xe5:
+            raise self.printer.command_error("Invalid adxl345 id (got %x vs %x)"
+                                             % (response[1], 0xe5))
+        # Setup chip in requested query rate
+        clock = 0
+        if self.last_tx_time:
+            clock = self.mcu.print_time_to_clock(self.last_tx_time)
+        self.spi.spi_send([REG_POWER_CTL, 0x00], minclock=clock)
+        self.spi.spi_send([REG_FIFO_CTL, 0x00])
+        self.spi.spi_send([REG_DATA_FORMAT, 0x0B])
+        self.spi.spi_send([REG_BW_RATE, QUERY_RATES[rate]])
+        self.spi.spi_send([REG_FIFO_CTL, 0x80])
+        # Setup samples
+        print_time = self.printer.lookup_object('toolhead').get_last_move_time()
+        self.raw_samples = []
+        self.last_sequence = 0
+        self.samples_start1 = self.samples_start2 = print_time
+        # Start bulk reading
+        reqclock = self.mcu.print_time_to_clock(print_time)
+        rest_ticks = self.mcu.seconds_to_clock(4. / rate)
+        self.last_tx_time = print_time
+        self.query_rate = rate
+        self.query_adxl345_cmd.send([self.oid, reqclock, rest_ticks],
+                                    reqclock=reqclock)
+    def finish_measurements(self):
+        query_rate = self.query_rate
+        if not query_rate:
+            return ADXL345Results()
+        # Halt bulk reading
+        print_time = self.printer.lookup_object('toolhead').get_last_move_time()
+        clock = self.mcu.print_time_to_clock(print_time)
+        params = self.query_adxl345_end_cmd.send([self.oid, 0, 0],
+                                                 minclock=clock)
+        self.last_tx_time = print_time
+        self.query_rate = 0
+        raw_samples = self.raw_samples
+        self.raw_samples = []
+        # Generate results
+        end1_time = self._clock_to_print_time(params['end1_time'])
+        end2_time = self._clock_to_print_time(params['end2_time'])
+        end_sequence = self._convert_sequence(params['sequence'])
+        overflows = params['limit_count']
+        res = ADXL345Results()
+        res.setup_data(self.axes_map, raw_samples, end_sequence, overflows,
+                       self.samples_start1, self.samples_start2,
+                       end1_time, end2_time)
+        logging.info("ADXL345 finished %d measurements: %s",
+                     len(res.get_samples()), res.get_stats())
+        return res
+    def end_query(self, name):
+        if not self.query_rate:
+            return
+        res = self.finish_measurements()
+        # Write data to file
+        f = open("/tmp/adxl345-%s.csv" % (name,), "w")
+        f.write("##%s\n#time,accel_x,accel_y,accel_z\n" % (res.get_stats(),))
+        for t, accel_x, accel_y, accel_z in res.get_samples():
+            f.write("%.6f,%.6f,%.6f,%.6f\n" % (t, accel_x, accel_y, accel_z))
+        f.close()
+    cmd_ACCELEROMETER_MEASURE_help = "Start/stop accelerometer"
+    def cmd_ACCELEROMETER_MEASURE(self, gcmd):
+        rate = gcmd.get_int("RATE", 0)
+        if not rate:
+            name = gcmd.get("NAME", time.strftime("%Y%m%d_%H%M%S"))
+            if not name.replace('-', '').replace('_', '').isalnum():
+                raise gcmd.error("Invalid adxl345 NAME parameter")
+            self.end_query(name)
+            gcmd.respond_info("adxl345 measurements stopped")
+        elif self.query_rate:
+            raise gcmd.error("adxl345 already running")
+        elif rate not in QUERY_RATES:
+            raise gcmd.error("Not a valid adxl345 query rate")
+        else:
+            self.start_measurements(rate)
+
+def load_config(config):
+    return ADXL345(config)
+
+def load_config_prefix(config):
+    return ADXL345(config)

src/Makefile

@@ -7,4 +7,4 @@ src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c thermocouple.c
 src-$(CONFIG_HAVE_GPIO_I2C) += i2ccmds.c
 src-$(CONFIG_HAVE_GPIO_HARD_PWM) += pwmcmds.c
 src-$(CONFIG_HAVE_GPIO_BITBANGING) += lcd_st7920.c lcd_hd44780.c buttons.c \
-    tmcuart.c spi_software.c neopixel.c
+    tmcuart.c spi_software.c neopixel.c sensor_adxl345.c

src/sensor_adxl345.c

@@ -0,0 +1,179 @@
+// Support for gathering acceleration data from ADXL345 chip
+//
+// Copyright (C) 2020  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include <string.h> // memcpy
+#include "board/irq.h" // irq_disable
+#include "board/misc.h" // timer_read_time
+#include "basecmd.h" // oid_alloc
+#include "command.h" // DECL_COMMAND
+#include "sched.h" // DECL_TASK
+#include "spicmds.h" // spidev_transfer
+
+struct adxl345 {
+    struct timer timer;
+    uint32_t rest_ticks, stop_time;
+    struct spidev_s *spi;
+    uint16_t sequence, limit_count;
+    uint8_t flags, data_count;
+    uint8_t data[48];
+};
+
+enum {
+    AX_HAVE_START = 1<<0, AX_RUNNING = 1<<1, AX_PENDING = 1<<2,
+};
+
+static struct task_wake adxl345_wake;
+
+static uint_fast8_t
+adxl345_event(struct timer *timer)
+{
+    struct adxl345 *ax = container_of(timer, struct adxl345, timer);
+    ax->flags |= AX_PENDING;
+    sched_wake_task(&adxl345_wake);
+    return SF_DONE;
+}
+
+void
+command_config_adxl345(uint32_t *args)
+{
+    struct adxl345 *ax = oid_alloc(args[0], command_config_adxl345
+                                   , sizeof(*ax));
+    ax->timer.func = adxl345_event;
+    ax->spi = spidev_oid_lookup(args[1]);
+}
+DECL_COMMAND(command_config_adxl345, "config_adxl345 oid=%c spi_oid=%c");
+
+// Report local measurement buffer
+static void
+adxl_report(struct adxl345 *ax, uint8_t oid)
+{
+    sendf("adxl345_data oid=%c sequence=%hu data=%*s"
+          , oid, ax->sequence, ax->data_count, ax->data);
+    ax->data_count = 0;
+    ax->sequence++;
+}
+
+// Chip registers
+#define AR_POWER_CTL   0x2D
+#define AR_DATAX0      0x32
+#define AR_FIFO_STATUS 0x39
+#define AM_READ  0x80
+#define AM_MULTI 0x40
+
+// Query accelerometer data
+static void
+adxl_query(struct adxl345 *ax, uint8_t oid)
+{
+    uint8_t msg[9] = { AR_DATAX0 | AM_READ | AM_MULTI, 0, 0, 0, 0, 0, 0, 0, 0 };
+    spidev_transfer(ax->spi, 1, sizeof(msg), msg);
+    memcpy(&ax->data[ax->data_count], &msg[1], 6);
+    ax->data_count += 6;
+    if (ax->data_count + 6 > ARRAY_SIZE(ax->data))
+        adxl_report(ax, oid);
+    uint_fast8_t fifo_status = msg[8] & ~0x80; // Ignore trigger bit
+    if (fifo_status >= 31 && ax->limit_count != 0xffff)
+        ax->limit_count++;
+    if (fifo_status > 1 && fifo_status <= 32) {
+        // More data in fifo - wake this task again
+        sched_wake_task(&adxl345_wake);
+    } else if (ax->flags & AX_RUNNING) {
+        // Sleep until next check time
+        sched_del_timer(&ax->timer);
+        ax->flags &= ~AX_PENDING;
+        irq_disable();
+        ax->timer.waketime = timer_read_time() + ax->rest_ticks;
+        sched_add_timer(&ax->timer);
+        irq_enable();
+    }
+}
+
+// Startup measurements
+static void
+adxl_start(struct adxl345 *ax, uint8_t oid)
+{
+    sched_del_timer(&ax->timer);
+    ax->flags = AX_RUNNING;
+    uint8_t msg[2] = { AR_POWER_CTL, 0x08 };
+    uint32_t start1_time = timer_read_time();
+    spidev_transfer(ax->spi, 0, sizeof(msg), msg);
+    irq_disable();
+    uint32_t start2_time = timer_read_time();
+    ax->timer.waketime = start2_time + ax->rest_ticks;
+    sched_add_timer(&ax->timer);
+    irq_enable();
+    sendf("adxl345_start oid=%c start1_time=%u start2_time=%u"
+          , oid, start1_time, start2_time);
+}
+
+// End measurements
+static void
+adxl_stop(struct adxl345 *ax, uint8_t oid)
+{
+    // Disable measurements
+    sched_del_timer(&ax->timer);
+    ax->flags = 0;
+    uint8_t msg[2] = { AR_POWER_CTL, 0x00 };
+    uint32_t end1_time = timer_read_time();
+    spidev_transfer(ax->spi, 0, sizeof(msg), msg);
+    uint32_t end2_time = timer_read_time();
+    // Drain any measurements still in fifo
+    uint_fast8_t i;
+    for (i=0; i<33; i++) {
+        msg[0] = AR_FIFO_STATUS | AM_READ;
+        msg[1] = 0;
+        spidev_transfer(ax->spi, 1, sizeof(msg), msg);
+        if (!(msg[1] & 0x3f))
+            break;
+        adxl_query(ax, oid);
+    }
+    // Report final data
+    if (ax->data_count)
+        adxl_report(ax, oid);
+    sendf("adxl345_end oid=%c end1_time=%u end2_time=%u"
+          " limit_count=%hu sequence=%hu"
+          , oid, end1_time, end2_time, ax->limit_count, ax->sequence);
+}
+
+void
+command_query_adxl345(uint32_t *args)
+{
+    struct adxl345 *ax = oid_lookup(args[0], command_config_adxl345);
+
+    if (!args[2]) {
+        // End measurements
+        adxl_stop(ax, args[0]);
+        return;
+    }
+    // Start new measurements query
+    sched_del_timer(&ax->timer);
+    ax->timer.waketime = args[1];
+    ax->rest_ticks = args[2];
+    ax->flags = AX_HAVE_START;
+    ax->sequence = ax->limit_count = 0;
+    ax->data_count = 0;
+    sched_add_timer(&ax->timer);
+}
+DECL_COMMAND(command_query_adxl345,
+             "query_adxl345 oid=%c clock=%u rest_ticks=%u");
+
+void
+adxl345_task(void)
+{
+    if (!sched_check_wake(&adxl345_wake))
+        return;
+    uint8_t oid;
+    struct adxl345 *ax;
+    foreach_oid(oid, ax, command_config_adxl345) {
+        uint_fast8_t flags = ax->flags;
+        if (!(flags & AX_PENDING))
+            continue;
+        if (flags & AX_HAVE_START)
+            adxl_start(ax, oid);
+        else
+            adxl_query(ax, oid);
+    }
+}
+DECL_TASK(adxl345_task);