diff options
Diffstat (limited to 'firmware/src/p2m.c')
| -rw-r--r-- | firmware/src/p2m.c | 152 |
1 files changed, 138 insertions, 14 deletions
diff --git a/firmware/src/p2m.c b/firmware/src/p2m.c index 11fe393..d44a01c 100644 --- a/firmware/src/p2m.c +++ b/firmware/src/p2m.c @@ -6,9 +6,11 @@ #include <LPC17xx.h>
-//#define SPI
-#define IRQ_BLINKY
+//#define IRQ_BLINKY
//#define BLINKY
+//#define BLINKY
+//#define WM8523
+#define SPI
#ifdef DMA
@@ -71,7 +73,7 @@ int main (void) }
-#endif
+#endif/*IRQ_BLINKY*/
#ifdef BLINKY
@@ -90,7 +92,7 @@ int main (void) }
-#endif
+#endif/*BLINKY*/
#ifdef UART
@@ -130,9 +132,9 @@ int main (void) }
}
-#endif
+#endif/*UART*/
-#ifdef SPI
+#ifdef WM8523
#include <cli.h>
#include <wm8523.h>
@@ -145,24 +147,146 @@ int main (void) LED_Init();
- cli_init();
-
- cli_write("init");
-
_delay(1 << 22);
WM8523_init();
- cli_write("pre");
-
_delay(1 << 22);
WM8523_configure();
- cli_write("post");
+ // Indicate that we didn't crash before the end...
+ int i = 0;
+ while(1) {
+ LED_toggle();
+ _delay(1 << 21);
+ i = 1 - i;
+ }
}
-#endif
+#endif/*WM8523*/
+
+#ifdef SPI
+// 1. Introduction
+/*
+ SPI is one of the most used serial interfaces on PCB level. This tutorial
+ explains how to use SPI to read or write data. For SPI the SPI library is
+ required. It can be downloaded from our repository. The library provides
+ commands for communicating over SPI.
+*/
+
+// 2. Includes
+#include <LPC17xx.h>
+//#include "lpc_types.h"
+#include <ssp.h>
+#include <GPIO.h>
+#include <timer.h>
+#include <led.h>
+
+typedef unsigned char uint8_t;
+
+int main (void)
+{
+ LED_Init(); // Bent code
+
+ // 3. Initializing
+ /*
+ SPI uses 4 IO pins, 1 clock, 1 MOSI, data from master to slave, 1 MISO,
+ data from slave to master and one Chip select pin. Every SPI IC has a Chip
+ Select pin, when the pin is low that IC will be selected to communicate
+ with. Every SPI IC that has a high value on the Chip Select pin will ignore
+ all signals on their data pins. 1 normal IO pin is used for the Chip Select,
+ the clock; MOSI and MISO are SPI pins. Any IO pin can be used for Chip
+ Select, For the tutorial pin 0.0 is used.
+ The timer has to be initialized to use it for delays and the GPIO pin for
+ Chip Select has to be initialized as output and made high, the code for
+ that is:
+ */
+ // TimerInit(0, 1000);
+
+ GPIOSetDir(0, 16, 1);
+ GPIOSetValue(0, 16, 1);
+
+ /*
+ There are 2 SPI channels, SSP0 and SSP1. SSP0 uses pin 0.15 for the clock;
+ pin 0.17 for MISO and pin 0.18 for MOSI. SSP1 uses pin 0.7 for the clock;
+ pin 0.8 for MISO and pin 0.9 for MOSI. To initialize a SPI port the
+ command SSP*channelno*init(); is used. To initialize SPI channel 1 the
+ command is:
+ */
+ SSP0Init();
+
+ /*
+ Some variables are also needed. SPI needs 2 array buffers, one for data
+ that has to be send trough the SPI slave and one for data received from
+ the SPI slave. Also its recommended to declare a variable with the value
+ of the SPI channel that is used:
+ */
+ uint8_t src_addr[16]; //16 byte Write buffer
+ uint8_t dest_addr[16]; //16 byte Read buffer
+ uint8_t portnum = 0;
+
+ // 4. Write data to SPI
+ /*
+ First the Chip Select has to be made low with the GPIOSetValue command:
+ GPIOSetValue(0, 0, 0;)
+ The data that has to be written should be placed in the src_addr array that
+ was declared earlier. To write 5 bytes of data (0x48, 0x65, 0x6c, 0x6c,
+ 0x6f the ascii code for Hello) place the hex data in the buffer array:
+ */
+
+ GPIOSetValue(0, 16, 0);
+
+ src_addr[0] = 0x1 << 7;
+ src_addr[1] = 0xff;
+ src_addr[2] = 0xff;
+
+ /*
+ When the data is stored in the array all that is left is start the SPI data
+ transmission with the SSPSend( portnum, (uint8_t *)src_addr, datanumbers);
+ portnum is the used SPI port, (uint8_t *)src_addr is the send buffer,
+ datanumbers is the amount of databytes to be send. The command needed to
+ send the 5 databytes declared above is:
+ */
+ SSPSend(portnum, (uint8_t *)src_addr, 1);
+
+ /*
+ After the data is send the Chip Select pin needs to be made high again with
+ the command GPIOSetValue(0, 0, 1); . Also a small delay can be needed for
+ some SPI IC’s, 1 millisecond is enough most of the time, the command for a
+ small delay is: delayMs(0, 1);
+ */
+ // delayMs(0, 1);
+
+ // GPIOSetValue(0, 16, 1);
+
+ // 5. Read data from SPI
+ /*
+ To read data the Chip Select has to be made low with GPIOSetValue(0,0,0); .
+ To read data from SPI the command SSPReceive(portnum, (uint8_t *)dest_addr,
+ datanumbers); is used. Portnum is the used SPI port, (uint8_t *)dest_addr
+ is the receive buffer, datanumbers is the amount of databytes that have to
+ be read. A command to read 4 databytes is:
+ */
+ // GPIOSetValue(0, 16, 0);
+
+ SSPReceive(portnum, (uint8_t *)dest_addr, 3);
+
+ GPIOSetValue(0, 16, 1);
+ /*
+ The 4 databytes are now stored in dest_addr[0] to dest_addr[3]
+ */
+
+ // Indicate that we didn't crash before the end...
+ int i = 0;
+ while(1) {
+ LED_toggle();
+ _delay(1 << 21);
+ i = 1 - i;
+ }
+}
+
+#endif/*SPI*/
void _delay(uint32_t del)
{
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