platform/technic_hub: init all adc channel params

The STM32L4Cube HAL was updated via upstream MicroPython and contains significant changes to the ADC code. Apparently, this code is less forgiving of zero-values for certain parameters. This fixes the issue by ensuring that we initialize all parameters to a valid value. Fixes: pybricks/support#665
pybricks · Jun 11, 2022 · 2cf9bca · 2cf9bca
1 parent 4fc6f9d
commit 2cf9bca
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,8 +6,10 @@
 
 ### Fixed
 - Fixed motor not stopping at the end of `run_until_stalled` ([support#662]).
+- Fixed incorrect battery current reading on Technic hub ([support#665]).
 
 [support#662]: https://github.com/pybricks/support/issues/662
+[support#665]: https://github.com/pybricks/support/issues/665
 
 ## [3.2.0b1]
 

diff --git a/lib/pbio/platform/technic_hub/platform.c b/lib/pbio/platform/technic_hub/platform.c
@@ -579,8 +579,22 @@ const uint32_t MSIRangeTable[12] = {
 };
 
 void HAL_ADC_MspInit(ADC_HandleTypeDef *hadc) {
-    GPIO_InitTypeDef gpio_init = { };
-    ADC_ChannelConfTypeDef adc_ch_config = { };
+    GPIO_InitTypeDef gpio_init = {
+        .Pin = 0, // variable
+        .Mode = GPIO_MODE_ANALOG_ADC_CONTROL,
+        .Pull = GPIO_NOPULL,
+        .Speed = GPIO_SPEED_FREQ_LOW,
+        .Alternate = 0, // not used
+    };
+
+    ADC_ChannelConfTypeDef adc_ch_config = {
+        .Channel = 0, // variable
+        .Rank = 0, // variable
+        .SamplingTime = ADC_SAMPLETIME_640CYCLES_5,
+        .SingleDiff = ADC_SINGLE_ENDED,
+        .OffsetNumber = ADC_OFFSET_NONE,
+        .Offset = 0, // not used
+    };
 
     // clocks are enabled in SystemInit
     assert_param(__HAL_RCC_TIM6_IS_CLK_ENABLED());
@@ -592,32 +606,25 @@ void HAL_ADC_MspInit(ADC_HandleTypeDef *hadc) {
     // PC1, battery voltage
 
     gpio_init.Pin = GPIO_PIN_1;
-    gpio_init.Mode = GPIO_MODE_ANALOG_ADC_CONTROL;
-    gpio_init.Pull = GPIO_NOPULL;
     HAL_GPIO_Init(GPIOC, &gpio_init);
 
     adc_ch_config.Channel = ADC_CHANNEL_2;
     adc_ch_config.Rank = ADC_REGULAR_RANK_1;
-    adc_ch_config.SamplingTime = ADC_SAMPLETIME_640CYCLES_5;
     HAL_ADC_ConfigChannel(hadc, &adc_ch_config);
 
     // PC2, battery current
 
     gpio_init.Pin = GPIO_PIN_2;
-    gpio_init.Mode = GPIO_MODE_ANALOG_ADC_CONTROL;
-    gpio_init.Pull = GPIO_NOPULL;
     HAL_GPIO_Init(GPIOC, &gpio_init);
 
     adc_ch_config.Channel = ADC_CHANNEL_3;
     adc_ch_config.Rank = ADC_REGULAR_RANK_2;
-    adc_ch_config.SamplingTime = ADC_SAMPLETIME_640CYCLES_5;
     HAL_ADC_ConfigChannel(hadc, &adc_ch_config);
 
     // internal, temperature
 
     adc_ch_config.Channel = ADC_CHANNEL_TEMPSENSOR;
     adc_ch_config.Rank = ADC_REGULAR_RANK_3;
-    adc_ch_config.SamplingTime = ADC_SAMPLETIME_640CYCLES_5;
     HAL_ADC_ConfigChannel(hadc, &adc_ch_config);
 }
 

diff --git a/pybricks/common/pb_type_battery.c b/pybricks/common/pb_type_battery.c
@@ -32,6 +32,17 @@ STATIC mp_obj_t battery_current(void) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(battery_current_obj, battery_current);
 
+#include "stm32l4xx_hal.h"
+
+STATIC mp_obj_t battery_reg(void) {
+    mp_obj_t adc1[2];
+    adc1[0] = mp_obj_new_bytes((const byte*)ADC1, sizeof(ADC_TypeDef));
+    adc1[1] = mp_obj_new_bytes((const byte*)ADC1_COMMON, sizeof(ADC_Common_TypeDef));
+
+    return mp_obj_new_tuple(MP_ARRAY_SIZE(adc1), adc1);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(battery_reg_obj, battery_reg);
+
 #if !PYBRICKS_HUB_MOVEHUB
 
 STATIC mp_obj_t battery_type(void) {
@@ -63,6 +74,7 @@ STATIC const mp_rom_map_elem_t battery_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__),    MP_ROM_QSTR(MP_QSTR_battery)        },
     { MP_ROM_QSTR(MP_QSTR_voltage),     MP_ROM_PTR(&battery_voltage_obj)    },
     { MP_ROM_QSTR(MP_QSTR_current),     MP_ROM_PTR(&battery_current_obj)    },
+    { MP_ROM_QSTR(MP_QSTR_reg),     MP_ROM_PTR(&battery_reg_obj)    },
     #if !PYBRICKS_HUB_MOVEHUB
     { MP_ROM_QSTR(MP_QSTR_type),        MP_ROM_PTR(&battery_type_obj)       },
     { MP_ROM_QSTR(MP_QSTR_temperature), MP_ROM_PTR(&battery_temperature_obj) },