Sensor hub

Functions
bool	ipc_sensorhub_init (void)
	Pipe-callback registration — second in the boot prologue.
void	ipc_sensorhub_snapshot (sensorhub_snapshot_t *snap)
	One consumer per tick — reading clears the changed flags.
bool	ipc_sensorhub_wifi_connected (void)
	Polled WiFi state — edge-detect before touching LVGL.
bool	ipc_sensorhub_ble_connected (void)
	True only while a NUS host is CONNECTED; no shipped caller.
bool	ipc_sensorhub_ntp_synced (void)
	The gate on reading the RTC at all.
bool	ipc_sensorhub_get_time_str (char *buf, size_t buf_size)
	Latest CM33-pushed time string; false before NTP sync.
void	ipc_sensorhub_feed_capsense (const ipc_sensor_capsense_t *data)
	Local CapSense sample injection — every field initialised, shared sequence.
void	ipc_sensorhub_feed_pot (const ipc_sensor_pot_t *data)
	Normalised pot values, not ADC counts; check pot_channels_ready() first.
void	ipc_sensorhub_feed_bmi270 (const ipc_sensor_bmi270_t *data)
	Local IMU sample injection; no shipped caller.
void	ipc_sensorhub_feed_bmm350 (const ipc_sensor_bmm350_t *data)
	Local magnetometer sample injection; no shipped caller.

Detailed Description

Header: ipc_sensorhub.h. Implementation: archived ipc_sensorhub.c (libbento_ipc.a). The ISR half stores the latest sample from every sensor CM33_NS pushes; readers take a sensorhub_snapshot_t. On boards where CM55 owns the sensor bus (Eva Kit, TESAIoT Dev Kit base board) the feed_* functions inject samples read locally on CM55 into the same store.

Variant

mtb-mpy and mtb-only

Function Documentation

ipc_sensorhub_init()

bool ipc_sensorhub_init

(

void

)

Pipe-callback registration — second in the boot prologue.

Initialize IPC sensorhub receiver. Registers IPC pipe callback on CM55_IPC_SENSOR_CLIENT_ID. Must be called AFTER cm55_ipc_communication_setup().

Returns

true on success.

Contract

"Must be called AFTER \c cm55_ipc_communication_setup()" (ipc_sensorhub.h). The archived display controller calls it second in the boot prologue, before ipc_service_init() and before GFXSS bring-up, so sensor IPC survives a display failure. Registers the pipe callback on CM55_IPC_SENSOR_CLIENT_ID. Consumers using the shipped display controller never call it.

Variant

mtb-mpy and mtb-only

Origin

Lifted from TESAIoT_KIT_PSE84_AI-Micropython-BentoClaw/proj_cm55/modules/lvgl_display/controller/tesaiot_display.c:223-238 (compiled into the prebuilt archive; not shipped as source).

ipc_sensorhub_snapshot()

void ipc_sensorhub_snapshot

(

sensorhub_snapshot_t *

snap

)

One consumer per tick — reading clears the changed flags.

Take a snapshot of the latest sensor data. Clears the "changed" flags after reading. Safe to call from any task context.

Parameters

snap	Output snapshot struct.

Contract

The caller owns a stack sensorhub_snapshot_t and passes its address. The header says "Safe to call from any task context" but also "Clears the 'changed' flags after reading" — so exactly one consumer per tick may call it. That is why the UI takes one snapshot at 33 ms and fans it out via pm_render() instead of each page snapshotting independently. Two archived callers in other contexts confirm the any-task claim: the AI inference task (ai_engine.c:795) and the IPC service task (ipc_service.c:729). Void.

Variant

mtb-mpy and mtb-only

static void sensorhub_timer_cb(lv_timer_t *timer)
{
    (void)timer;
 
    /* Take snapshot of all sensor data from IPC */
    sensorhub_snapshot_t snap;
    ipc_sensorhub_snapshot(&snap);
 
    /* Dispatch render to current page (skips if animating) */
    pm_render(&s_pm, &snap);
 
    /* Update global topbar (time + WiFi) on current page */
    if (!s_pm.animating) {
        pm_update_topbar(&s_pm);
    }
}

ipc_sensorhub_wifi_connected()

bool ipc_sensorhub_wifi_connected

(

void

)

Polled WiFi state — edge-detect before touching LVGL.

Returns true if CM33_NS reported WiFi connected via IPC_CMD_WIFI_STATE_PUSH

Contract

Polled — no callback API exists. The edge-detect pattern is mandatory: compare the polled state against the widget's current LVGL flag and touch LVGL only on a real transition; unconditional add_flag / clear_flag every tick causes visible card-row flicker. Widget-null-guarded, because the page can be destroyed between ticks. Runs at the ~6 fps topbar throttle, skipped while animating.

Variant

mtb-mpy and mtb-only

    /* ...context: inside pm_update_topbar() - GFX task context ... */
    /* WiFi icon — only toggle visibility when state actually changes
     * to prevent unnecessary LVGL invalidation (card row flicker). */
    if (pm->wifi_lbl) {
        bool connected = ipc_sensorhub_wifi_connected();
        bool hidden = lv_obj_has_flag(pm->wifi_lbl, LV_OBJ_FLAG_HIDDEN);
        if (connected && hidden) {
            lv_obj_clear_flag(pm->wifi_lbl, LV_OBJ_FLAG_HIDDEN);
        } else if (!connected && !hidden) {
            lv_obj_add_flag(pm->wifi_lbl, LV_OBJ_FLAG_HIDDEN);
        }
    }

ipc_sensorhub_ble_connected()

bool ipc_sensorhub_ble_connected

(

void

)

True only while a NUS host is CONNECTED; no shipped caller.

Returns true if CM33_NS reported BLE NUS host CONNECTED via IPC_CMD_BLE_STATE_PUSH. Only true while a host is connected; advertising/idle return false.

Contract

True only while a NUS host is CONNECTED (IPC_CMD_BLE_STATE_PUSH); advertising and idle read false. No shipped caller anywhere — the authored example models it on the wifi_connected edge-detect pattern: GFX-task only, widget null-guarded, LVGL touched only on a change.

Variant

mtb-mpy and mtb-only

Example (authored — no shipped call site)

static lv_obj_t *s_ble_lbl;           /* created by the page's create_cb,
                                       * NULLed by its destroy_cb           */
 
__attribute__((used))
static void bento_ex_ipc_sensorhub_ble_connected(void)
{
    if (s_ble_lbl == NULL) {
        return;                        /* page gone — widget freed          */
    }
 
    bool connected = ipc_sensorhub_ble_connected();
    bool hidden    = lv_obj_has_flag(s_ble_lbl, LV_OBJ_FLAG_HIDDEN);
 
    /* Edge detect: touch LVGL only on a state CHANGE. */
    if (connected && hidden) {
        lv_obj_clear_flag(s_ble_lbl, LV_OBJ_FLAG_HIDDEN);
    } else if (!connected && !hidden) {
        lv_obj_add_flag(s_ble_lbl, LV_OBJ_FLAG_HIDDEN);
    }
}

ipc_sensorhub_ntp_synced()

bool ipc_sensorhub_ntp_synced

(

void

)

The gate on reading the RTC at all.

Returns true if CM33_NS has sent at least one IPC_CMD_TIME_PUSH (NTP synced)

Returns true after CM33_NS sends IPC_CMD_NTP_SYNCED (RTC is valid).

Contract

The gate on reading the RTC at all: Cy_RTC_GetDateAndTime() is called only after CM33_NS has sent the NTP-synced notification. A true return is necessary but not sufficient — the shipped code still range-validates rtc.month and rtc.dayOfWeek before indexing its name tables. Note the strcmp before lv_label_set_text so the label is not invalidated every tick (card-row flicker). ~6 fps throttle inside pm_update_topbar, skipped while animating.

Variant

mtb-mpy and mtb-only

    /* ...context: inside pm_update_topbar() - GFX task context ... */
    /* RTC time display — only after NTP sync notification from CM33_NS */
    if (pm->time_lbl && ipc_sensorhub_ntp_synced()) {
        static const char * const dow[] = {
            "", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
        };
        static const char * const mon[] = {
            "", "Jan", "Feb", "Mar", "Apr", "May", "Jun",
            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
        };
        cy_stc_rtc_config_t rtc;
        Cy_RTC_GetDateAndTime(&rtc);
        if (rtc.month >= 1 && rtc.month <= 12 &&
            rtc.dayOfWeek >= 1 && rtc.dayOfWeek <= 7) {
            char buf[32];
            snprintf(buf, sizeof(buf), "%s %d %s %02d:%02d",
                     dow[rtc.dayOfWeek], (int)rtc.date,
                     mon[rtc.month], (int)rtc.hour, (int)rtc.min);
            /* Only invalidate if text actually changed (prevents card row flicker) */
            if (strcmp(lv_label_get_text(pm->time_lbl), buf) != 0) {
                lv_label_set_text(pm->time_lbl, buf);
            }

ipc_sensorhub_get_time_str()

bool ipc_sensorhub_get_time_str	(	char *	buf,
		size_t	buf_size )

Latest CM33-pushed time string; false before NTP sync.

Copy the latest time string from CM33_NS (e.g. "Mon 10 Mar 14:35"). Returns false if NTP not yet synced. buf must be >= 32 bytes.

Contract

Copies the latest time string pushed by CM33_NS; returns false when NTP has not synced. buf must be at least 32 bytes. No shipped caller — the topbar reads the RTC directly behind the ntp_synced gate instead. The authored example pairs it with that gate.

Variant

mtb-mpy and mtb-only

Example (authored — no shipped call site)

__attribute__((used))
static void bento_ex_ipc_sensorhub_get_time_str(void)
{
    /* Gate first: false before the first NTP push — necessary, and this
     * call re-checks it anyway (returns false while unsynced). */
    if (!ipc_sensorhub_ntp_synced()) {
        return;                        /* show nothing rather than garbage */
    }
 
    char now[32];                      /* header contract: >= 32 bytes     */
    if (!ipc_sensorhub_get_time_str(now, sizeof(now))) {
        return;
    }
 
    /* Drive a label only on change (flicker discipline, GFX task):
     *   if (strcmp(lv_label_get_text(lbl), now) != 0)
     *       lv_label_set_text(lbl, now);
     */
    (void)now;
}

ipc_sensorhub_feed_capsense()

void ipc_sensorhub_feed_capsense

(

const ipc_sensor_capsense_t *

data

)

Local CapSense sample injection — every field initialised, shared sequence.

Contract

Every field must be initialised, including reserved = 0, and sequence must increment monotonically from a counter shared with the pot feed — one sequence space per producer. The producer is a single writer on the GFX task; that is what makes the byte-sized cached fields readable from the CM33 IPC_CMD_CONTROLS_STATE snapshot path without a lock. Void; the wrapper's bool reports the I2C read, not the feed.

Variant

mtb-mpy and mtb-only

    /* ...context: inside capsense_read_and_feed() - GFX task context ... */
    ipc_sensor_capsense_t d;
    d.btn0_pressed = (btn0_code != s_caps_idle_btn0) ? 1 : 0;
    d.btn1_pressed = (btn1_code != s_caps_idle_btn1) ? 1 : 0;
    d.slider = buf[2];
    d.reserved = 0;
    d.sequence = s_seq++;
 
    /* Cache the decoded state for the CM33 IPC_CMD_CONTROLS_STATE snapshot
     * (byte-size fields — single-writer GFX task, torn reads impossible). */
    s_caps_btn0   = d.btn0_pressed;
    s_caps_btn1   = d.btn1_pressed;
    s_caps_slider = d.slider;
    s_caps_live   = true;
 
    ipc_sensorhub_feed_capsense(&d);
    return true;

ipc_sensorhub_feed_pot()

void ipc_sensorhub_feed_pot

(

const ipc_sensor_pot_t *

data

)

Normalised pot values, not ADC counts; check pot_channels_ready() first.

Contract

The API carries normalised values, not ADC counts: raw rescaled to the full uint16 range and percent_x10 in per-mille, both from POT_ADC_MAX. The whole feed function sits inside BSP_HAS_POTENTIOMETER. Before any feed the shipped code runs pot_channels_ready() (cm55_sensor_poll.c:189-198): a SAR read result of 0 is not proof the channel is live, so the per-channel status bit is checked first. Same shared s_seq counter as capsense.

Variant

mtb-mpy and mtb-only

static bool pot_read_and_feed(void)
{
    for (uint8_t i = 0; i < QWA309_POT_COUNT; i++) {
        s_pot_raw[i] = pot_read_channel(i);
    }
 
    /* Feed VR1 (channel 0) to the single-value pot IPC so the Controls page
     * and the pot MicroPython snapshot light up unchanged. */
    uint16_t adc0 = s_pot_raw[0];
    ipc_sensor_pot_t d;
    d.raw         = (uint16_t)((uint32_t)adc0 * 65535U / POT_ADC_MAX);
    d.percent_x10 = (uint16_t)((uint32_t)adc0 * 1000U / POT_ADC_MAX);
    d.sequence    = s_seq++;
 
    ipc_sensorhub_feed_pot(&d);
    return true;
}

ipc_sensorhub_feed_bmi270()

void ipc_sensorhub_feed_bmi270

(

const ipc_sensor_bmi270_t *

data

)

Local IMU sample injection; no shipped caller.

Contract

No shipped caller anywhere. The authored example follows the feed_capsense discipline exactly: full struct initialisation, monotonic sequence from the producer's own counter, single-writer GFX-task context.

Variant

mtb-mpy and mtb-only

Example (authored — no shipped call site)

static uint16_t s_imu_seq;            /* ONE sequence space for this
                                       * producer — shared by the bmi270
                                       * and bmm350 feeds below            */
 
__attribute__((used))
static void bento_ex_ipc_sensorhub_feed_bmi270(void)
{
    /* Raw values as read from the sensor on the CM55-owned bus. */
    int16_t ax = 0, ay = 0, az = 4096; /* +1 g at ±8g scale               */
    int16_t gx = 0, gy = 0, gz = 0;
 
    ipc_sensor_bmi270_t d;             /* full struct init — every field   */
    d.ax = ax;
    d.ay = ay;
    d.az = az;
    d.gx = gx;
    d.gy = gy;
    d.gz = gz;
    d.sequence = s_imu_seq++;
 
    ipc_sensorhub_feed_bmi270(&d);
}

ipc_sensorhub_feed_bmm350()

void ipc_sensorhub_feed_bmm350

(

const ipc_sensor_bmm350_t *

data

)

Local magnetometer sample injection; no shipped caller.

Contract

No shipped caller anywhere. Same contract as feed_bmi270: every field set, sequence discipline, single producer.

Variant

mtb-mpy and mtb-only

Example (authored — no shipped call site)

__attribute__((used))
static void bento_ex_ipc_sensorhub_feed_bmm350(void)
{
    ipc_sensor_bmm350_t d;             /* full struct init — every field   */
    d.mx_x100     = 2150;              /* 21.50 uT                         */
    d.my_x100     = -430;              /* -4.30 uT                         */
    d.mz_x100     = 4890;              /* 48.90 uT                         */
    d.heading_x10 = 923;               /* 92.3 degrees                     */
    d.sequence    = s_imu_seq++;       /* same producer sequence space     */
 
    ipc_sensorhub_feed_bmm350(&d);
}