drv/battery_adc: Add support for Li-ion batteries

dlech · dlech · commit 64e9c2c86892 · 2020-11-06T17:36:32.000-06:00
This allow use of Li-ion batteries in the Technic hub (even though
there isn't an official battery pack from LEGO).

This also fixes low battery shutdown on Prime hub.

Issue: pybricks/pybricks-micropython#5
diff --git a/lib/pbio/drv/battery/battery_adc.c b/lib/pbio/drv/battery/battery_adc.c
@@ -28,6 +28,10 @@
 // PBDRV_CONFIG_BATTERY_ADC_CURRENT_SCALED_MAX:
 //      The current in mA that corresponds that would result in the raw measured
 //      value PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_MAX being read on the ADC.
+// PBDRV_CONFIG_BATTERY_ADC_TYPE:
+//      1 = PBDRV_BATTERY_TYPE_ALKALINE only
+//      2 = PBDRV_BATTERY_TYPE_LIION only
+//      3 = type indicated by GPIO button
 
 #include <pbdrv/config.h>
 
@@ -38,9 +42,23 @@
 #include <contiki.h>
 
 #include <pbdrv/adc.h>
+#include <pbdrv/battery.h>
+#include <pbdrv/gpio.h>
 #include <pbio/error.h>
 
+#include "battery_adc.h"
+
+#if PBDRV_CONFIG_BATTERY_ADC_TYPE == 3
+static pbdrv_battery_type_t pbdrv_battery_type;
+#endif
+
 void pbdrv_battery_init() {
+    #if PBDRV_CONFIG_BATTERY_ADC_TYPE == 3
+    const pbdrv_battery_adc_platform_data_t *pdata = &pbdrv_battery_adc_platform_data;
+    pbdrv_gpio_set_pull(&pdata->gpio, pdata->pull);
+    pbdrv_battery_type = pbdrv_gpio_input(&pdata->gpio) ?
+        PBDRV_BATTERY_TYPE_ALKALINE : PBDRV_BATTERY_TYPE_LIION;
+    #endif
 }
 
 pbio_error_t pbdrv_battery_get_current_now(uint16_t *value) {
@@ -104,4 +122,16 @@ pbio_error_t pbdrv_battery_get_voltage_now(uint16_t *value) {
     return PBIO_SUCCESS;
 }
 
+pbdrv_battery_type_t pbdrv_battery_get_type() {
+    #if PBDRV_CONFIG_BATTERY_ADC_TYPE == 1
+    return PBDRV_BATTERY_TYPE_ALKALINE;
+    #elif PBDRV_CONFIG_BATTERY_ADC_TYPE == 2
+    return PBDRV_BATTERY_TYPE_LIION;
+    #elif PBDRV_CONFIG_BATTERY_ADC_TYPE == 3
+    return pbdrv_battery_type;
+    #else
+    #error "Bad PBDRV_CONFIG_BATTERY_ADC_TYPE value"
+    #endif
+}
+
 #endif // PBDRV_CONFIG_BATTERY_ADC
diff --git a/lib/pbio/drv/battery/battery_adc.h b/lib/pbio/drv/battery/battery_adc.h
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2020 The Pybricks Authors
+
+#ifndef _PBDRV_BATTERY_ADC_H_
+#define _PBDRV_BATTERY_ADC_H_
+
+#include <pbdrv/gpio.h>
+
+// NOTE: Currently platform data is only needed for this driver when
+// PBDRV_CONFIG_BATTERY_ADC_TYPE == 3
+
+/**
+ * Platform data for ADC battery device.
+ */
+typedef struct {
+    /** Battery type detection GPIO. */
+    pbdrv_gpio_t gpio;
+    /** Battery type detection GPIO pull setting. */
+    pbdrv_gpio_pull_t pull;
+} pbdrv_battery_adc_platform_data_t;
+
+// defined in platform.c
+const pbdrv_battery_adc_platform_data_t pbdrv_battery_adc_platform_data;
+
+#endif // _PBDRV_BATTERY_ADC_H_
diff --git a/lib/pbio/drv/battery/battery_nxt.c b/lib/pbio/drv/battery/battery_nxt.c
@@ -13,12 +13,14 @@
 #include <contiki.h>
 #include <nxt/nxt_avr.h>
 
+#include <pbdrv/battery.h>
 #include <pbio/error.h>
 
 void pbdrv_battery_init() {
 }
 
 pbio_error_t pbdrv_battery_get_voltage_now(uint16_t *value) {
+    // Battery voltage includes bit 0x8000 to indicate rechargeable battery
     *value = battery_voltage() & 0x7FFF;
     return PBIO_SUCCESS;
 }
@@ -28,4 +30,10 @@ pbio_error_t pbdrv_battery_get_current_now(uint16_t *value) {
     return PBIO_ERROR_NOT_SUPPORTED;
 }
 
+pbdrv_battery_type_t pbdrv_battery_get_type() {
+    // Battery voltage includes bit 0x8000 to indicate rechargeable battery
+    return (battery_voltage() & 0x8000) ? PBDRV_BATTERY_TYPE_LIION
+                                        : PBDRV_BATTERY_TYPE_ALKALINE;
+}
+
 #endif // PBDRV_CONFIG_BATTERY_NXT
diff --git a/lib/pbio/include/pbdrv/battery.h b/lib/pbio/include/pbdrv/battery.h
@@ -14,8 +14,17 @@
 #include <pbdrv/config.h>
 #include <pbio/error.h>
 
-#if PBDRV_CONFIG_BATTERY
+/** Battery chemistry types. */
+typedef enum {
+    /** The battery type is not known. */
+    PBDRV_BATTERY_TYPE_UNKNOWN,
+    /** The batteries are alkaline (e.g. AA/AAA). */
+    PBDRV_BATTERY_TYPE_ALKALINE,
+    /** The batteries are Li-ion. */
+    PBDRV_BATTERY_TYPE_LIION,
+} pbdrv_battery_type_t;
 
+#if PBDRV_CONFIG_BATTERY
 
 /** @cond INTERNAL */
 void pbdrv_battery_init();
@@ -39,6 +48,12 @@ pbio_error_t pbdrv_battery_get_voltage_now(uint16_t *value);
  */
 pbio_error_t pbdrv_battery_get_current_now(uint16_t *value);
 
+/**
+ * Gets the battery chemistry type.
+ * @return              The type of battery.
+ */
+pbdrv_battery_type_t pbdrv_battery_get_type();
+
 #else // PBDRV_CONFIG_BATTERY
 
 #define pbdrv_battery_init()
@@ -53,6 +68,10 @@ static inline pbio_error_t pbdrv_battery_get_current_now(uint16_t *value) {
     return PBIO_ERROR_NOT_SUPPORTED;
 }
 
+static inline pbdrv_battery_type_t pbdrv_battery_get_type() {
+    return PBDRV_BATTERY_TYPE_UNKNOWN;
+}
+
 #endif // PBDRV_CONFIG_BATTERY
 
 #endif // _PBDRV_BATTERY_H_
diff --git a/lib/pbio/platform/city_hub/pbdrvconfig.h b/lib/pbio/platform/city_hub/pbdrvconfig.h
@@ -19,6 +19,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_OFFSET 130
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_MAX    4096
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_SCALED_MAX 2448
+#define PBDRV_CONFIG_BATTERY_ADC_TYPE               (1)
 
 #define PBDRV_CONFIG_BUTTON                         (1)
 #define PBDRV_CONFIG_BUTTON_GPIO                    (1)
diff --git a/lib/pbio/platform/move_hub/pbdrvconfig.h b/lib/pbio/platform/move_hub/pbdrvconfig.h
@@ -19,6 +19,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_OFFSET 0
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_MAX    4096
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_SCALED_MAX 2448
+#define PBDRV_CONFIG_BATTERY_ADC_TYPE               (1)
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
 
diff --git a/lib/pbio/platform/prime_hub/pbdrvconfig.h b/lib/pbio/platform/prime_hub/pbdrvconfig.h
@@ -26,6 +26,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_OFFSET 0
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_MAX    4096
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_SCALED_MAX 7300
+#define PBDRV_CONFIG_BATTERY_ADC_TYPE               (2)
 
 #define PBDRV_CONFIG_BUTTON                         (1)
 #define PBDRV_CONFIG_BUTTON_ADC                     (1)
diff --git a/lib/pbio/platform/prime_hub/sys.c b/lib/pbio/platform/prime_hub/sys.c
@@ -8,7 +8,9 @@
 #include "pbio/event.h"
 #include "pbio/main.h"
 
+#include <pbsys/battery.h>
 #include <pbsys/status.h>
+#include <pbsys/supervisor.h>
 #include <pbsys/sys.h>
 
 #include "../sys/hmi.h"
@@ -43,6 +45,7 @@ PROCESS_THREAD(pbsys_process, ev, data) {
 
     PROCESS_BEGIN();
 
+    pbsys_battery_init();
     pbsys_hmi_init();
     etimer_set(&timer, clock_from_msec(50));
 
@@ -51,7 +54,9 @@ PROCESS_THREAD(pbsys_process, ev, data) {
         pbsys_hmi_handle_event(ev, data);
         if (ev == PROCESS_EVENT_TIMER && etimer_expired(&timer)) {
             etimer_reset(&timer);
+            pbsys_battery_poll();
             pbsys_hmi_poll();
+            pbsys_supervisor_poll();
         } else if (ev == PBIO_EVENT_STATUS_SET) {
             if ((pbsys_status_t)data == PBSYS_STATUS_POWER_BUTTON_PRESSED && user_stop_func) {
                 user_stop_func();
diff --git a/lib/pbio/platform/technic_hub/pbdrvconfig.h b/lib/pbio/platform/technic_hub/pbdrvconfig.h
@@ -24,6 +24,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_OFFSET 20
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_RAW_MAX    4096
 #define PBDRV_CONFIG_BATTERY_ADC_CURRENT_SCALED_MAX 4178
+#define PBDRV_CONFIG_BATTERY_ADC_TYPE               (3)
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
 
diff --git a/lib/pbio/platform/technic_hub/platform.c b/lib/pbio/platform/technic_hub/platform.c
@@ -6,6 +6,7 @@
 #include "pbio/uartdev.h"
 
 #include "../../drv/adc/adc_stm32_hal.h"
+#include "../../drv/battery/battery_adc.h"
 #include "../../drv/button/button_gpio.h"
 #include "../../drv/ioport/ioport_lpf2.h"
 #include "../../drv/led/led_pwm.h"
@@ -42,6 +43,15 @@ enum {
 
 // PBIO driver data
 
+// Battery
+
+const pbdrv_battery_adc_platform_data_t pbdrv_battery_adc_platform_data = {
+    .gpio = { .bank = GPIOA, .pin = 12 },
+    .pull = PBDRV_GPIO_PULL_NONE,
+};
+
+// Button
+
 const pbdrv_button_gpio_platform_t pbdrv_button_gpio_platform[PBDRV_CONFIG_BUTTON_GPIO_NUM_BUTTON] = {
     [0] = {
         .gpio = { .bank = GPIOC, .pin = 14 },
diff --git a/lib/pbio/sys/battery.c b/lib/pbio/sys/battery.c
@@ -22,20 +22,49 @@
 #define BATTERY_LOW_MV          5400    // 0.9V per cell
 #define BATTERY_CRITICAL_MV     4800    // 0.8V per cell
 
-static uint16_t avg_battery_voltage;
+// These values are for LEGO rechargeable battery packs
+#define LIION_OK_MV             7000    // 3.5V per cell
+#define LIION_LOW_MV            6600    // 3.3V per cell
+#define LIION_CRITICAL_MV       6000    // 3.0V per cell
+
 static clock_time_t prev_poll_time;
+static uint16_t avg_battery_voltage;
+
+#if PBDRV_CONFIG_BATTERY_ADC_TYPE == 1
+// special case to reduce code size on Move hub
+#define battery_critical_mv BATTERY_CRITICAL_MV
+#define battery_low_mv BATTERY_LOW_MV
+#define battery_ok_mv BATTERY_OK_MV
+#else
+static uint16_t battery_critical_mv;
+static uint16_t battery_low_mv;
+static uint16_t battery_ok_mv;
+#endif
 
 /**
  * Initializes the system battery moitor.
  */
 void pbsys_battery_init() {
+    #if PBDRV_CONFIG_BATTERY_ADC_TYPE != 1
+    if (pbdrv_battery_get_type() == PBDRV_BATTERY_TYPE_LIION) {
+        battery_critical_mv = LIION_CRITICAL_MV;
+        battery_low_mv = LIION_LOW_MV;
+        battery_ok_mv = LIION_OK_MV;
+    } else {
+        battery_critical_mv = BATTERY_CRITICAL_MV;
+        battery_low_mv = BATTERY_LOW_MV;
+        battery_ok_mv = BATTERY_OK_MV;
+    }
+    #endif
+
     pbdrv_battery_get_voltage_now(&avg_battery_voltage);
     // This is mainly for the Technic Hub. It seems that the first battery voltage
     // read is always low and causes the hub to shut down because of low battery
     // voltage even though the battery isn't that low.
-    if (avg_battery_voltage < BATTERY_CRITICAL_MV) {
-        avg_battery_voltage = BATTERY_OK_MV;
+    if (avg_battery_voltage < battery_critical_mv) {
+        avg_battery_voltage = battery_ok_mv;
     }
+
     prev_poll_time = clock_time();
 }
 
@@ -58,15 +87,15 @@ void pbsys_battery_poll() {
     avg_battery_voltage = (avg_battery_voltage * (BATTERY_PERIOD_MS - poll_interval)
         + battery_voltage * poll_interval) / BATTERY_PERIOD_MS;
 
-    if (avg_battery_voltage <= BATTERY_CRITICAL_MV) {
+    if (avg_battery_voltage <= battery_critical_mv) {
         pbsys_status_set(PBSYS_STATUS_BATTERY_LOW_VOLTAGE_SHUTDOWN);
-    } else if (avg_battery_voltage >= BATTERY_LOW_MV) {
+    } else if (avg_battery_voltage >= battery_low_mv) {
         pbsys_status_clear(PBSYS_STATUS_BATTERY_LOW_VOLTAGE_SHUTDOWN);
     }
 
-    if (avg_battery_voltage <= BATTERY_LOW_MV) {
+    if (avg_battery_voltage <= battery_low_mv) {
         pbsys_status_set(PBSYS_STATUS_BATTERY_LOW_VOLTAGE_WARNING);
-    } else if (avg_battery_voltage >= BATTERY_OK_MV) {
+    } else if (avg_battery_voltage >= battery_ok_mv) {
         pbsys_status_clear(PBSYS_STATUS_BATTERY_LOW_VOLTAGE_WARNING);
     }
 }
