SPI no clock or data

[keithco]

I have been struggling trying to communicate with a TMP127-Q1 digital temperature sensor using a ESP32-S3-MINI.
Using my Oscilloscope, I am not seeing clock or data. The error I am getting is this: E (5804824) spi_master: check_trans_valid(684): invalid dev handle
Here is my SPI code.

Code: [Select all] [Expand/Collapse]

1. /*
2.  * temp_SPI-6.c
3.  *
4.  *  Created on: Apr 12, 2023
5.  *      Author: keith
6.  */
7.  
8. #include <stdio.h>
9. #include "freertos/FreeRTOS.h"
10. #include "freertos/task.h"
11. #include "driver/gpio.h"
12. #include "driver/spi_master.h"
13.  
14. #include "temp_SPI-6.h"
15.  
16. #define USE_SPI_MODE
17. #define SPI_BUS       SPI3_HOST
18. #define GPIO_CS         4
19. #define GPIO_SIO        37
20. #define GPIO_CLK        36
21. //#define GPIO_IRQ      2   // IRQ pin
22.  
23. #define TMP127_REG_TEMP     0x01
24.  
25. spi_device_handle_t spi_device;
26. spi_transaction_t *trans_desc;
27.  
28. void tmp127_spi_init()
29. {
30.     spi_bus_config_t bus_cfg = {
31.         .miso_io_num = GPIO_SIO,
32.         .mosi_io_num = -1,
33.         .sclk_io_num = GPIO_CLK,
34.         .quadwp_io_num = -1,
35.         .quadhd_io_num = -1,
36.         .max_transfer_sz = 32,
37.     };
38.  
39.     spi_bus_initialize(SPI3_HOST, &bus_cfg, 1);
40.  
41.     spi_device_interface_config_t dev_cfg = {
42.         .clock_speed_hz = 1000000,          // Clock out at 1 MHz
43.         .mode = 0,                          // SPI mode 0
44.         .spics_io_num = GPIO_CS,            // CS pin
45.         .queue_size = 1,
46. //      .flags = SPI_DEVICE_NO_DUMMY,
47.     };
48.  
49. //    spi_bus_initialize(SPI_BUS, &bus_cfg, 1);
50. //    spi_bus_add_device(SPI_BUS, &dev_cfg, &spi_device);
51.     spi_bus_initialize(SPI3_HOST, &bus_cfg, 1);
52.     spi_bus_add_device(SPI3_HOST, &dev_cfg, &spi_device);
53.     spi_device_acquire_bus(spi_device, portMAX_DELAY);
54.  
55. //    gpio_set_direction(GPIO_CS, GPIO_MODE_OUTPUT);
56. //    gpio_set_direction(GPIO_CLK, GPIO_MODE_OUTPUT);
57. //    gpio_set_direction(GPIO_SIO, GPIO_MODE_INPUT);
58. }
59.  
60. int16_t tmp127_read_temperature()
61. {
62. //    uint8_t tx_data[2] = {TMP127_REG_TEMP, 0};
63. //    uint8_t rx_data[2] = {0, 0};
64.     uint8_t rx_data[2] = {0};
65.     spi_transaction_t trans_desc = {
66. //      .tx_buffer = tx_data,
67.         .rx_buffer = rx_data,
68.         .length = 16,
69.         .flags = SPI_TRANS_USE_RXDATA,
70.     };
71.  
72. //    spi_device_transmit(spi_device, &trans_desc);
73.     spi_device_polling_start(spi_device, &trans_desc, portMAX_DELAY);
74.  
75.     spi_device_polling_transmit(spi_device, &trans_desc);
76.     int16_t temperature = (rx_data[0] << 8) | rx_data[1] >> 4;
77. //    int16_t temperature = (rx_data[1] << 8) | rx_data[2];
78. //    temperature >>= 4;  // Remove lower 4 bits (fractional part)
79. //    temperature = temperature / 128;
80.     return temperature;
81. }

GeSHi © Codebox Plus Extension

[ESP_Sprite]

You are not checking any of your spi driver calls for errors. Either do that manually or use the ESP_ERROR_CHECK macro. That'll likely tell you what fails.

[keithco]

Thank you! I'll give that a try. I forgot to point out that I am using these pins for clock and data. Is this okay?

Code: [Select all] [Expand/Collapse]

1. #define GPIO_CS         4
2. #define GPIO_SIO        37
3. #define GPIO_CLK        36

GeSHi © Codebox Plus Extension

[keithco]

I've implemented the macro call ESP_ERROR_CHECK now. No errors until I add:

Code: [Select all] [Expand/Collapse]

1. ESP_ERROR_CHECK(spi_device_polling_transmit(spi_device, &trans_desc));

GeSHi © Codebox Plus Extension

Still no clock or data... Here is my most recent code.

Code: [Select all] [Expand/Collapse]

1. /*
2.  * temp_SPI-6.c
3.  *
4.  *  Created on: Apr 12, 2023
5.  *      Author: keith
6.  */
7.  
8. #include <stdio.h>
9. #include "freertos/FreeRTOS.h"
10. #include "freertos/task.h"
11. #include "driver/gpio.h"
12. #include "driver/spi_master.h"
13. #include "esp_log.h"
14.  
15. #include "temp_SPI-6.h"
16.  
17. #define USE_SPI_MODE
18. #define SPI_BUS       SPI2_HOST
19. #define GPIO_CS         4
20. #define GPIO_SIO        37
21. #define GPIO_CLK        36
22.  
23. #define TMP127_REG_TEMP     0x01
24.  
25. spi_device_handle_t spi_device;
26. spi_transaction_t *trans_desc;
27.  
28. void tmp127_spi_init()
29. {
30.     spi_bus_config_t bus_cfg = {
31.         .miso_io_num = GPIO_SIO,
32.         .mosi_io_num = -1,
33.         .sclk_io_num = GPIO_CLK,
34.         .quadwp_io_num = -1,
35.         .quadhd_io_num = -1,
36.         .max_transfer_sz = 32,
37.     };
38.  
39.     // Initialize the SPI bus
40.     ESP_ERROR_CHECK(spi_bus_initialize(SPI2_HOST, &bus_cfg, 1));
41.  
42.     spi_device_interface_config_t dev_cfg = {
43.         .clock_speed_hz = 1000000,          // Clock out at 1 MHz
44.         .mode = 0,                          // SPI mode 0
45.         .spics_io_num = GPIO_CS,            // CS pin
46.         .queue_size = 1,
47. //      .flags = SPI_DEVICE_NO_DUMMY,
48.     };
49.  
50.     ESP_ERROR_CHECK(spi_bus_add_device(SPI2_HOST, &dev_cfg, &spi_device));
51.     ESP_ERROR_CHECK(spi_device_acquire_bus(spi_device, portMAX_DELAY));
52.  
53. }
54.  
55. int16_t tmp127_read_temperature()
56. {
57. //    uint8_t tx_data[2] = {TMP127_REG_TEMP, 0};
58.     uint8_t rx_data[2] = {0};
59.     spi_transaction_t trans_desc = {
60. //      .tx_buffer = tx_data,
61.         .rx_buffer = rx_data,
62.         .length = 32,
63.         .flags = SPI_TRANS_USE_RXDATA,
64.     };
65.  
66. //    ESP_ERROR_CHECK(spi_device_transmit(spi_device, &trans_desc));
67. //    ESP_ERROR_CHECK(spi_device_polling_start(spi_device, &trans_desc, portMAX_DELAY));
68.     ESP_ERROR_CHECK(spi_device_polling_transmit(spi_device, &trans_desc));
69.     int16_t temperature = (trans_desc.rx_data[0] << 4);
70.  
71.     return temperature;
72. }

GeSHi © Codebox Plus Extension

[ESP_Sprite]

Are you sure your code calls tmp127_spi_init before tmp127_read_temperature is first called?

[keithco]

Hello ESP_Sprite,

You nailed it. I forgot that I had commented out the function call "tmp127_spi_init".
There were several other issues but now are reliably reading from the TMP127-Q1 digital temperature sensor.
Thanks for your help...

Here is the working code:

Code: Select all

/*
 * temp_SPI-6.c
 *
 *  Created on: Apr 12, 2023
 *      Author: keith
 */

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "esp_log.h"

#include "temp_SPI-6.h"

#define USE_SPI_MODE
#define SPI_BUS       SPI3_HOST
#define GPIO_CS       	4
#define GPIO_SIO       	37
#define GPIO_CLK       	36

#define TEMP_FACTOR    0.118 //
#define TMP127_REG_TEMP     0x01

spi_device_handle_t spi_device;
spi_transaction_t *trans_desc;

void tmp127_spi_init()
{
    spi_bus_config_t bus_cfg = {
        .miso_io_num = GPIO_SIO,
        .mosi_io_num = -1,
        .sclk_io_num = GPIO_CLK,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
        .max_transfer_sz = 32,
    };

    // Initialize the SPI bus
    ESP_ERROR_CHECK(spi_bus_initialize(SPI3_HOST, &bus_cfg, 0));

    spi_device_interface_config_t dev_cfg = {
        .clock_speed_hz = 1000000,          // Clock out at 1 MHz
        .mode = 0,                          // SPI mode 0
        .spics_io_num = GPIO_CS,            // CS pin
        .queue_size = 1,
		.flags = SPI_DEVICE_NO_DUMMY,
    };

    ESP_ERROR_CHECK(spi_bus_add_device(SPI3_HOST, &dev_cfg, &spi_device));
    ESP_ERROR_CHECK(spi_device_acquire_bus(spi_device, portMAX_DELAY));
}

int16_t tmp127_read_temperature()
{
    uint8_t tx_data[2] = {TMP127_REG_TEMP, 0};
    uint8_t rx_data[2] = {0,0};
    spi_transaction_t trans_desc = {
		.tx_buffer = tx_data,
		.rx_buffer = rx_data,
        .length = 16,
    };

    ESP_ERROR_CHECK(spi_device_polling_transmit(spi_device, &trans_desc));

    int16_t temperature = (rx_data[0] << 8) | rx_data[1];
    temperature >>= 4;  // Remove lower 4 bits
    return temperature;
}

[ESP_Sprite]

You're welcome, glad you got it to work!