commit ebcaec6086118627e36090fb482b5c0546d7ed7f
parent 44defb82561a08db184f8849d382d87557ef57a9
Author: Martin Kloeckner <mjkloeckner@gmail.com>
Date: Sun, 22 Mar 2026 19:01:35 -0300
Usar UART con DMA para enviar comandos al sensor DS18B20
Diffstat:
2 files changed, 97 insertions(+), 6 deletions(-)
diff --git a/firmware/app/inc/ds18b20.h b/firmware/app/inc/ds18b20.h
@@ -51,10 +51,15 @@ extern "C" {
typedef enum {
ST_DS18B20_READY,
+ ST_DS18B20_BUSY_SENDING_RESET,
+ ST_DS18B20_BUSY_SENDING_SKIP_ROM,
+ ST_DS18B20_BUSY_SENDING_CONV_T,
+ ST_DS18B20_BUSY_SENDING_READ_SCRATCHPAD,
ST_DS18B20_BUSY_WAITING_CONV,
ST_DS18B20_BUSY_WAITING_DMA
} DS18B20_st_t;
+
void DS18B20_Init(void);
void DS18B20_Update(void);
diff --git a/firmware/app/src/ds18b20.c b/firmware/app/src/ds18b20.c
@@ -24,7 +24,7 @@ volatile bool b_DS18B20_Received_data;
static uint8_t g_DS18B20_Received_data_buffer[8];
const uint8_t g_buffer[8] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
static bool b_DS18B20_Received_data_LSB;
-DS18B20_st_t g_DS18B20_state;
+DS18B20_st_t g_DS18B20_state, g_DS18B20_prev_state;
uint32_t g_DS18B20_tick;
uint16_t g_DS18B20_temp;
@@ -95,7 +95,7 @@ void DS18B20_Init(void)
LOGGER_INFO("Temperature sensor initialized successfully");
}
DS18B20_SetResolution(9);
- g_DS18B20_state = ST_DS18B20_READY;
+ g_DS18B20_state = g_DS18B20_prev_state = ST_DS18B20_READY;
g_DS18B20_tick = G_TEMP_PERIOD_MS;
g_DS18B20_update_count = 0;
g_DS18B20_DMA_error_count = 0;
@@ -124,6 +124,28 @@ void DS18B20_Write(uint8_t data)
HAL_UART_Transmit(&huart1, buffer, 8, 100);
}
+uint8_t g_DS18B20_TX_buffer[8];
+bool b_DS18B20_DMA_done = false;
+
+void DS18B20_Write_DMA(uint8_t data)
+{
+ for (uint8_t i = 0; i < 8; ++i)
+ {
+ if (data & (1 << i))
+ {
+ g_DS18B20_TX_buffer[i] = 0xFF;
+ }
+ else
+ {
+ g_DS18B20_TX_buffer[i] = 0x00;
+ }
+ }
+
+ b_DS18B20_DMA_done = false;
+ HAL_UART_Transmit_DMA(&huart1, g_DS18B20_TX_buffer, 8);
+}
+
+
void DS18B20_Start_conv(void)
{
// Send start temp conversion command
@@ -142,21 +164,56 @@ void DS18B20_Update(void)
case ST_DS18B20_READY:
if (0 == g_DS18B20_tick)
{
- DS18B20_Start_conv();
- g_DS18B20_state = ST_DS18B20_BUSY_WAITING_CONV;
- g_DS18B20_tick = G_DS18B20_CONV_TIME_MS;
+ // DS18B20_Start_conv();
+ g_DS18B20_prev_state = g_DS18B20_state;
+ g_DS18B20_state = ST_DS18B20_BUSY_SENDING_SKIP_ROM;
l_DS18B20_DMA_error_count = 0;
+ DS18B20_Reset(); // Blocking ~500us
+ DS18B20_Write_DMA(0xCC); // Send 'Skip ROM' command
}
else
{
g_DS18B20_tick--;
}
break;
+ case ST_DS18B20_BUSY_SENDING_SKIP_ROM:
+ if (true == b_DS18B20_DMA_done)
+ {
+ switch (g_DS18B20_prev_state)
+ {
+ case ST_DS18B20_READY:
+ g_DS18B20_prev_state = g_DS18B20_state;
+ g_DS18B20_state = ST_DS18B20_BUSY_SENDING_CONV_T;
+ DS18B20_Write_DMA(0x44); // Send 'Convert T' command
+ break;
+ case ST_DS18B20_BUSY_WAITING_CONV:
+ g_DS18B20_prev_state = g_DS18B20_state;
+ g_DS18B20_state = ST_DS18B20_BUSY_SENDING_READ_SCRATCHPAD;
+ DS18B20_Write_DMA(0xBE); // Send 'read scratchpad' command
+ break;
+ default:
+ g_DS18B20_state = ST_DS18B20_READY;
+ break;
+ }
+ }
+ break;
+ case ST_DS18B20_BUSY_SENDING_CONV_T:
+ if (true == b_DS18B20_DMA_done)
+ {
+ g_DS18B20_state = ST_DS18B20_BUSY_WAITING_CONV;
+ g_DS18B20_tick = G_DS18B20_CONV_TIME_MS;
+ }
+ break;
case ST_DS18B20_BUSY_WAITING_CONV:
if (0 == g_DS18B20_tick)
{
DS18B20_Reset();
- DS18B20_Write(0xCC); // Send 'Skip ROM' command
+ DS18B20_Write_DMA(0xCC); // Send 'Skip ROM' command
+
+ g_DS18B20_prev_state = g_DS18B20_state;
+ g_DS18B20_state = ST_DS18B20_BUSY_SENDING_SKIP_ROM;
+
+ /*
DS18B20_Write(0xBE); // Send 'read scratchpad' command
HAL_UART_Transmit_DMA(&huart1, g_buffer, 8);
@@ -165,6 +222,7 @@ void DS18B20_Update(void)
b_DS18B20_Received_data_LSB = true;
g_DS18B20_state = ST_DS18B20_BUSY_WAITING_DMA;
g_DS18B20_tick = G_DS18B20_DMA_TIMEOUT_MS;
+ */
}
else
{
@@ -173,6 +231,18 @@ void DS18B20_Update(void)
break;
+ case ST_DS18B20_BUSY_SENDING_READ_SCRATCHPAD:
+ if (true == b_DS18B20_DMA_done)
+ {
+ HAL_UART_Transmit_DMA(&huart1, g_buffer, 8);
+ HAL_UART_Receive_DMA(&huart1, g_DS18B20_Received_data_buffer, 8);
+
+ b_DS18B20_Received_data_LSB = true;
+ g_DS18B20_state = ST_DS18B20_BUSY_WAITING_DMA;
+ g_DS18B20_tick = G_DS18B20_DMA_TIMEOUT_MS;
+ }
+ break;
+
case ST_DS18B20_BUSY_WAITING_DMA:
// Process received byte if any
if (true == b_DS18B20_Received_data)
@@ -257,6 +327,22 @@ void DS18B20_Update(void)
}
}
+void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
+{
+ if (huart->Instance == USART1)
+ {
+ switch (g_DS18B20_state)
+ {
+ case ST_DS18B20_BUSY_SENDING_SKIP_ROM:
+ case ST_DS18B20_BUSY_SENDING_CONV_T:
+ case ST_DS18B20_BUSY_SENDING_READ_SCRATCHPAD:
+ b_DS18B20_DMA_done = true;
+ break;
+ default: break;
+ }
+ }
+}
+
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart->Instance == USART1)
