8000 stm32: Add PulseOut support · gregdavill/circuitpython@611ef27 · GitHub
[go: up one dir, main page]
Skip to content

Commit 611ef27

Browse files
hierophecthierophect
committed
stm32: Add PulseOut support
Matches the implementations of the NRF and Atmel ports. TIM7 is used as it does not have a tied pin. Contains some register micromanagement since HAL support for the TIM7 timer is limited.
1 parent 1b33cd1 commit 611ef27

File tree

4 files changed

+157
-4
lines changed

4 files changed

+157
-4
lines changed

‎ports/stm32f4/common-hal/pulseio/PWMOut.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -163,7 +163,7 @@ pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
163163
} else if (var_freq_mismatch) {
164164
mp_raise_ValueError(translate("Cannot vary frequency on a timer that is already in use"));
165165
} else {
166-
mp_raise_ValueError(translate("Invalid pins"));
166+
mp_raise_ValueError(translate("Invalid pins for PWMOut"));
167167
}
168168
}
169169

‎ports/stm32f4/common-hal/pulseio/PulseOut.c

Lines changed: 153 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -35,21 +35,172 @@
3535
#include "shared-bindings/pulseio/PWMOut.h"
3636
#include "supervisor/shared/translate.h"
3737

38+
#include "stm32f4xx_hal.h"
39+
#include "common-hal/microcontroller/Pin.h"
40+
#include "tick.h"
41+
42+
// A single timer is shared amongst all PulseOut objects under the assumption that
43+
// the code is single threaded.
44+
STATIC uint8_t refcount = 0;
45+
46+
STATIC uint16_t *pulse_array = NULL;
47+
STATIC volatile uint16_t pulse_array_index = 0;
48+
STATIC uint16_t pulse_array_length;
49+
50+
//Timer is shared, must be accessible by interrupt
51+
STATIC TIM_HandleTypeDef t7_handle;
52+
pulseio_pulseout_obj_t *curr_pulseout = NULL;
53+
54+
STATIC void turn_on(pulseio_pulseout_obj_t *pulseout) {
55+
// Turn on PWM
56+
HAL_TIM_PWM_Start(&(pulseout->pwmout->handle), pulseout->pwmout->channel);
57+
}
58+
59+
STATIC void turn_off(pulseio_pulseout_obj_t *pulseout) {
60+
// Turn off PWM
61+
HAL_TIM_PWM_Stop(&(pulseout->pwmout->handle), pulseout->pwmout->channel);
62+
// Make sure pin is low.
63+
HAL_GPIO_WritePin(pin_port(pulseout->pwmout->tim->pin->port),
64+
pin_mask(pulseout->pwmout->tim->pin->number), 0);
65+
}
66+
67+
STATIC void start_timer(void) {
68+
// Set the new period
69+
t7_handle.Init.Period = pulse_array[pulse_array_index] - 1;
70+
HAL_TIM_Base_Init(&t7_handle);
71+
72+
// TIM7 has limited HAL support, set registers manually
73+
t7_handle.Instance->SR = 0; // Prevent the SR from triggering an interrupt
74+
t7_handle.Instance->CR1 |= TIM_CR1_CEN; // Resume timer
75+
t7_handle.Instance->CR1 |= TIM_CR1_URS; // Disable non-overflow interrupts
76+
__HAL_TIM_ENABLE_IT(&t7_handle, TIM_IT_UPDATE);
77+
78+
}
79+
80+
STATIC void pulseout_event_handler(void) {
81+
if (curr_pulseout->pwmout == NULL) {
82+
return; //invalid interrupt
83+
}
84+
85+
HAL_GPIO_WritePin(pin_port(2),pin_mask(6), 1);
86+
HAL_GPIO_WritePin(pin_port(2),pin_mask(6), 0);
87+
88+
pulse_array_index++;
89+
90+
// No more pulses. Turn off output and don't restart.
91+
if (pulse_array_index >= pulse_array_length) {
92+
turn_off(curr_pulseout);
93+
return;
94+
}
95+
96+
// Alternate on and off, starting with on.
97+
if (pulse_array_index % 2 == 0) {
98+
turn_on(curr_pulseout);
99+
} else {
100+
turn_off(curr_pulseout);
101+
}
102+
103+
// Count up to the next given value.
104+
start_timer();
105+
}
38106

39107
void pulseout_reset() {
108+
__HAL_RCC_TIM7_CLK_DISABLE();
109+
refcount = 0;
40110
}
41111

42112
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t* self,
43113
const pulseio_pwmout_obj_t* carrier) {
44-
mp_raise_NotImplementedError(translate("PulseOut not yet supported"));
114+
// Add to active PulseOuts
115+
refcount++;
116+
117+
// Calculate a 1 ms period
118+
uint32_t source, clk_div;
119+
source = HAL_RCC_GetPCLK1Freq(); // TIM7 is on APB1
120+
clk_div = RCC->CFGR & RCC_CFGR_PPRE1;
121+
// APB quirk, see See DM00031020 Rev 4, page 115.
122+
if (clk_div != 0) {
123+
// APB prescaler for this timer is > 1
124+
source *= 2;
125+
}
126+
127+
uint32_t prescaler = source/1000000; //1us intervals
128+
129+
__HAL_RCC_TIM7_CLK_ENABLE();
130+
HAL_NVIC_SetPriority(TIM7_IRQn, 4, 0);
131+
HAL_NVIC_EnableIRQ(TIM7_IRQn);
132+
133+
// Timers 6 and 7 have no pins, so using them doesn't affect PWM availability
134+
t7_handle.Instance = TIM7;
135+
t7_handle.Init.Period = 100; //immediately replaced.
136+
t7_handle.Init.Prescaler = prescaler - 1;
137+
t7_handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
138+
t7_handle.Init.CounterMode = TIM_COUNTERMODE_UP;
139+
t7_handle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
140+
141+
HAL_TIM_Base_Init(&t7_handle);
142+
t7_handle.Instance->SR = 0;
143+
144+
// The HAL can't work with const, recast required.
145+
self->pwmout = (pulseio_pwmout_obj_t*)carrier;
146+
147+
turn_off(self);
45148
}
46149

47150
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t* self) {
48-
return true;
151+
return self->pwmout == NULL;
49152
}
50153

51154
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t* self) {
155+
if (common_hal_pulseio_pulseout_deinited(self)) {
156+
return;
157+
}
158+
turn_on(self);
159+
self->pwmout = NULL;
160+
161+
refcount--;
162+
if (refcount == 0) {
163+
__HAL_RCC_TIM7_CLK_DISABLE();
164+
}
52165
}
53166

54167
void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t* self, uint16_t* pulses, uint16_t length) {
168+
pulse_array = pulses;
169+
pulse_array_index = 0;
170+
pulse_array_length = length;
171+
curr_pulseout = self;
172+
173+
turn_on(self);
174+
175+
// Count up to the next given value.
176+
start_timer();
177+
178+
// Use when debugging, or issues are irrecoverable
179+
// uint32_t starttime = supervisor_ticks_ms64();
180+
// uint32_t timeout = 10000;
181+
while(pulse_array_index < length) {
182+
// Do other things while we wait. The interrupts will handle sending the
183+
// signal.
184+
RUN_BACKGROUND_TASKS;
185+
186+
// Use when debugging, or issues are irrecoverable
187+
// if ((supervisor_ticks_ms64() - starttime ) > timeout ) {
188+
// mp_raise_RuntimeError(translate("Error: Send Timeout"));
189+
// }
190+
}
191+
//turn off timer counter.
192+
t7_handle.Instance->CR1 &= ~TIM_CR1_CEN;
193+
}
194+
195+
void TIM7_IRQHandler(void)
196+
{
197+
// Detect TIM Update event
198+
if (__HAL_TIM_GET_FLAG(&t7_handle, TIM_FLAG_UPDATE) != RESET)
199+
{
200+
if (__HAL_TIM_GET_IT_SOURCE(&t7_handle, TIM_IT_UPDATE) != RESET)
201+
{
202+
__HAL_TIM_CLEAR_IT(&t7_handle, TIM_IT_UPDATE);
203+
pulseout_event_handler();
204+
}
205+
}
55206
}

‎ports/stm32f4/common-hal/pulseio/PulseOut.h

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -34,7 +34,7 @@
3434

3535
typedef struct {
3636
mp_obj_base_t base;
37-
const pulseio_pwmout_obj_t *pwmout;
37+
pulseio_pwmout_obj_t *pwmout;
3838
} pulseio_pulseout_obj_t;
3939

4040
void pulseout_reset(void);

‎ports/stm32f4/supervisor/port.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -35,6 +35,7 @@
3535
#include "common-hal/busio/SPI.h"
3636
#include "common-hal/busio/UART.h"
3737
#include "common-hal/pulseio/PWMOut.h"
38+
#include "common-hal/pulseio/PulseOut.h"
3839

3940
#include "stm32f4/clocks.h"
4041
#include "stm32f4/gpio.h"
@@ -60,6 +61,7 @@ void reset_port(void) {
6061
spi_reset();
6162
uart_reset();
6263
pwmout_reset();
64+
pulseout_reset();
6365
}
6466

6567
void reset_to_bootloader(void) {

0 commit comments

Comments
 (0)
0