Support SPI example. (#19)

* Support SPI example.

* Minor update

* Add ISR Usage

* Update SPI example

* Update ISR exmaple

* Minor update

* Minor update

Author: DanielHo-BS

examples/c/README.md

@@ -45,10 +45,33 @@ I2C_BUS means the supported I2C bus on ROScube platform, which starts from 0.
 ```
 
 # PWM
-`./pwm` can set the value to period of pwm.
+`./pwm <PWM_PIN> <PWM_FREQ>` can set the value to period of pwm.
 
 ```bash
 # For example, your pin of pwm is 22, and you want to set the period of pwm to 200us
 ./pwm 22 200
 # To exit, using ctrl + c
+```
+
+# SPI 
+`./spi <SPI_BUS> <SPI_FREQ>` can set the value to spi.
+
+Take MAX7219 chip with LED Matrix as example.  
+Display set of patterns on MAX7219 repeately.
+
+Note that we are using `/dev/spidev0.0`.
+
+```bash
+# For example, your spi_device is 0, and you want to set the speed to 100000 hz.
+./spi 0 100000
+# Press Ctrl+C to exit
+```
+
+# GPIO ISR
+`./gpio_advanced.c <PIN>` can configure GPIO pin for interruption.
+
+```bash
+# For example, configure Pin 5 for interruption.
+./gpio_advanced.c 
+# Press Ctrl+C to exit.
 ```

examples/c/gpio_advanced.c

@@ -6,8 +6,8 @@
  *
  * SPDX-License-Identifier: MIT
  *
- * Example usage: Configures GPIO pin for interrupt and waits 30 seconds for the isr to trigger
- *
+ * Example usage: Configures GPIO pin for interrupt.
+ *                Press Ctrl+C to exit.
  */
 
 /* standard headers */
@@ -16,46 +16,57 @@
 
 /* mraa header */
 #include "mraa/gpio.h"
+#include "mraa/led.h"
+
+/* GPIO default */
+#define GPIO_PIN1 5
 
-#define GPIO_PIN 6
+int count = 0;
 
-void
-int_handler(void* args)
-{
-    fprintf(stdout, "ISR triggered\n");
+void int_handler(void *arg) {
+    mraa_gpio_context gpio = (mraa_gpio_context)arg;
+    count += 1;
+    printf("pin %d = %d\n",mraa_gpio_get_pin(gpio),  mraa_gpio_read(gpio));
+    printf("count = %d\n", count);
 }
 
-int
-main()
-{
+int main(int argc, char *argv[]) {
     mraa_result_t status = MRAA_SUCCESS;
     mraa_gpio_context gpio;
+    int gpio_pin1;
+    gpio_pin1 = (argc >= 2)?atoi(argv[1]):GPIO_PIN1;
 
     /* initialize mraa for the platform (not needed most of the times) */
     mraa_init();
 
     //! [Interesting]
     /* initialize GPIO pin */
-    gpio = mraa_gpio_init(GPIO_PIN);
+    gpio = mraa_gpio_init(GPIO_PIN1);
+    /* Wait for the GPIO to initialize */
+    usleep(5000);
     if (gpio == NULL) {
-        fprintf(stderr, "Failed to initialize GPIO %d\n", GPIO_PIN);
+        fprintf(stderr, "Failed to initialize GPIO %d\n", GPIO_PIN1);
         mraa_deinit();
         return EXIT_FAILURE;
     }
 
-    /* set GPIO to input */
+    /* set GPIO1 to input */
     status = mraa_gpio_dir(gpio, MRAA_GPIO_IN);
+    usleep(5000);
     if (status != MRAA_SUCCESS) {
+        fprintf(stderr, "Failed to set GPIO1 to input\n");
         goto err_exit;
     }
 
     /* configure ISR for GPIO */
-    status = mraa_gpio_isr(gpio, MRAA_GPIO_EDGE_BOTH, &int_handler, NULL);
+    status = mraa_gpio_isr(gpio, MRAA_GPIO_EDGE_BOTH, &int_handler, (void *)gpio);
+    /* Wait for the ISR to configure */
+    usleep(5000);
     if (status != MRAA_SUCCESS) {
+        fprintf(stderr, "Failed to configure ISR\n");
         goto err_exit;
     }
 
-    /* wait 30 seconds isr trigger */
     sleep(30);
 
     /* close GPIO */

examples/c/spi.c

@@ -22,7 +22,10 @@
 #define SPI_BUS 0
 
 /* SPI frequency in Hz */
-#define SPI_FREQ 400000
+#define SPI_FREQ 100000
+
+/* SPI bits per word*/
+#define SPI_BIT 16
 
 uint16_t pat[] = { 0xaa01, 0x5502, 0xaa03, 0x5504, 0xaa05, 0x5506, 0xaa07, 0x5508 };
 uint16_t pat_inv[] = { 0x5501, 0xaa02, 0x5503, 0xaa04, 0x5505, 0xaa06, 0x5507, 0xaa08 };
@@ -45,69 +48,89 @@ main(int argc, char** argv)
     mraa_result_t status = MRAA_SUCCESS;
     mraa_spi_context spi;
     int i, j;
+    unsigned int tx_data[2];
+    int spi_bus, spi_freq, spi_bit;
+    spi_bus = (argc >= 2)?atoi(argv[1]):SPI_BUS;
+    spi_freq = (argc >= 3)?atoi(argv[2]):SPI_FREQ;
+    printf("Will set SPI BUS to %d, frequency to %d hz .\n", spi_bus, spi_freq);
 
     /* initialize mraa for the platform (not needed most of the times) */
     mraa_init();
+    usleep(50000);
 
     //! [Interesting]
     /* initialize SPI bus */
-    spi = mraa_spi_init(SPI_BUS);
+    spi = mraa_spi_init(spi_bus);
+    usleep(50000);
     if (spi == NULL) {
         fprintf(stderr, "Failed to initialize SPI\n");
         mraa_deinit();
         return EXIT_FAILURE;
     }
 
     /* set SPI frequency */
-    status = mraa_spi_frequency(spi, SPI_FREQ);
-    if (status != MRAA_SUCCESS)
+    status = mraa_spi_frequency(spi, spi_freq);
+    usleep(50000);
+    if (status != MRAA_SUCCESS){
         goto err_exit;
+    }
+        
 
     /* set big endian mode */
     status = mraa_spi_lsbmode(spi, 0);
+    usleep(50000);
     if (status != MRAA_SUCCESS) {
         goto err_exit;
     }
 
-    /* MAX7219/21 chip needs the data in word size */
-    status = mraa_spi_bit_per_word(spi, 16);
+    /* set the data in word size */
+    status = mraa_spi_bit_per_word(spi, SPI_BIT);
+    usleep(50000);
     if (status != MRAA_SUCCESS) {
-        fprintf(stdout, "Failed to set SPI Device to 16Bit mode\n");
+        fprintf(stdout, "Failed to set SPI Device to 16 Bit mode\n");
         goto err_exit;
     }
 
     /* do not decode bits */
     mraa_spi_write_word(spi, 0x0009);  //0x9 is for Decode mode, an 8x8 LEDs should be set to 0x00
-
+    usleep(50000);
+    
     /* brightness of LEDs */
     mraa_spi_write_word(spi, 0x050a);  //0xA is for intersity, could be set from 0x0 to 0xF and 0xF is the brightest.
+    usleep(50000);
+    
 
     /* show all scan lines */
     mraa_spi_write_word(spi, 0x070b);  //0xB is for Scan, means how many EEPROM you want to open. 
+    usleep(50000);
 
     /* set display on */
     mraa_spi_write_word(spi, 0x010c); //0xC: set to 0x0 for shutdown, 0x1 for open.
+    usleep(50000);
 
     /* testmode off */
     mraa_spi_write_word(spi, 0x000f); //0xF is for test mode, if set to 0x0 every LED will set bright.
+    usleep(50000);
 
     while (flag) {
         /* set display pattern */
-        for(i=0;i<sizeof(pat);i++)
+        for(i= 0 ; i < sizeof(pat); i++)
         {
             mraa_spi_write_word(spi, pat[i]);
+            usleep(50000);
         }
-        sleep(2);
+        sleep(1);
 
         /* set inverted display pattern */
-        for(i=0;i<sizeof(pat_inv);i++)
+        for(i = 0; i < sizeof(pat_inv); i++)
         {
             mraa_spi_write_word(spi, pat_inv[i]);
+            usleep(50000);
         }
-        sleep(2);
+        sleep(1);
 
         /* clear the LED's */
-        for(i=0;i<sizeof(pat_clear);i++)
+        for(i = 0; i < sizeof(pat_clear); i++)
         {
             mraa_spi_write_word(spi, pat_clear[i]);
         }
@@ -116,18 +139,20 @@ main(int argc, char** argv)
         for (i = 1; i <= 8; i++) {
             for (j = 0; j < 8; j++) {
                 mraa_spi_write_word(spi, i  + (1 << (j+8)));
-                sleep(1);
+                usleep(50000);
             }
             mraa_spi_write_word(spi, i << 8);
         }
     }
 
     /* stop spi */
     mraa_spi_stop(spi);
+    usleep(50000);
 
     //! [Interesting]
     /* deinitialize mraa for the platform (not needed most of the times) */
     mraa_deinit();
+    usleep(50000);
 
     return EXIT_SUCCESS;
 
@@ -136,9 +161,10 @@ main(int argc, char** argv)
 
     /* stop spi */
     mraa_spi_stop(spi);
+    usleep(50000);
 
     /* deinitialize mraa for the platform (not needed most of the times) */
     mraa_deinit();
-
+    usleep(50000);
     return EXIT_FAILURE;
 }

examples/python/README.md

@@ -52,4 +52,28 @@ python3 i2c.py 0 0x50
 # For example, your pin of pwm is 22, and you want to set the period of pwm to 200us
 python3 pwm.py 22 200
 # To exit, using ctrl + c
+```
+
+# SPI
+
+`python3 spi.py <SPI_Num> <SPI_Speed>` can set the value to the SPI.
+
+Take MAX7219 chip with LED Matrix as example.  
+Display set of patterns on MAX7219 repeately.
+
+Note that we are using `/dev/spidev0.0`.
+
+```bash
+# For example, your spi_device is 0, and you want to set the speed to 100000 hz.
+python3 spi.py 0 100000
+# Press Ctrl+C to exit
+```
+
+# GPIO ISR
+`python3 spi.py <GPIO_PIN>` can triggers ISR upon GPIO state change.
+
+```bash
+# For example, configure Pin 5 for interruption.
+python3 gpio_advanced.py 5.
+# Press ENTER to stop
 ```

examples/python/gpio_advanced.py

@@ -19,11 +19,12 @@ class Counter:
 # inside a python interrupt you cannot use 'basic' types so you'll need to use
 # objects
 def isr_routine(gpio):
-    print("pin " + repr(gpio.getPin(True)) + " = " + repr(gpio.read()))
     c.count += 1
+    print("pin " + repr(gpio.getPin(True)) + " = " + repr(gpio.read()))
+    print("count = ", c.count)
 
 # GPIO
-pin = 6;
+pin = 5 if len(sys.argv) < 2 else int(sys.argv[1])
 
 try:
     # initialise GPIO
@@ -36,7 +37,7 @@ def isr_routine(gpio):
     x.isr(mraa.EDGE_BOTH, isr_routine, x)
 
     # wait until ENTER is pressed
-    var = raw_input("Press ENTER to stop")
+    var = input("Press ENTER to stop\n")
     x.isrExit()
 except ValueError as e:
-    print(e)
+    print(e)