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/*
* Polling SPI loopback test.
*
* Bob is nowhere to be found, so Alice decides to talk to herself.
*
* Instructions: Connect SPI2 (Alice) to herself (i.e., MISO to MOSI).
* Connect to Alice via SerialUSB. Press any key to start.
*
* Alice will talk to herself for a little while. The sketch will
* report if Alice can't hear anything she says. She'll then start
* talking forever at various frequencies, bit orders, and modes. Use
* an oscilloscope to make sure she's not trying to lie about any of
* those things.
*
* This file is released into the public domain.
*
* Author: Marti Bolivar <mbolivar@leaflabs.com>
*/
#include "wirish.h"
HardwareSPI alice(2);
#define NFREQS 8
const SPIFrequency spi_freqs[] = {
SPI_140_625KHZ,
SPI_281_250KHZ,
SPI_562_500KHZ,
SPI_1_125MHZ,
SPI_2_25MHZ,
SPI_4_5MHZ,
SPI_9MHZ,
SPI_18MHZ,
};
#define TEST_BUF_SIZE 10
uint8 test_buf[TEST_BUF_SIZE] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
void bad_assert(const char* file, int line, const char* exp) {
SerialUSB.println();
SerialUSB.print("ERROR: FAILED ASSERT(");
SerialUSB.print(exp);
SerialUSB.print("): ");
SerialUSB.print(file);
SerialUSB.print(": ");
SerialUSB.println(line);
throb();
}
#undef ASSERT
#define ASSERT(exp) \
if (exp) { \
} else { \
bad_assert(__FILE__, __LINE__, #exp); \
}
void haveConversation(uint32 bitOrder);
void soliloquies(uint32 bitOrder);
void setup() {
pinMode(BOARD_LED_PIN, OUTPUT);
while (!SerialUSB.available())
;
SerialUSB.read();
}
void loop() {
SerialUSB.println("** Having a conversation, MSB first");
haveConversation(MSBFIRST);
SerialUSB.println("** Having a conversation, LSB first");
haveConversation(LSBFIRST);
SerialUSB.println();
SerialUSB.println("*** All done! It looks like everything worked.");
SerialUSB.println();
SerialUSB.println("** Alice will now wax eloquent in various styles. "
"Press any key for the next configuration.");
soliloquies(MSBFIRST);
soliloquies(LSBFIRST);
while (true)
;
}
void printFrequencyString(SPIFrequency frequency);
void chat(SPIFrequency frequency, uint32 bitOrder, uint32 mode);
void haveConversation(uint32 bitOrder) {
for (int f = 0; f < NFREQS; f++) {
for (int mode = 0; mode < 4; mode++) {
chat(spi_freqs[f], bitOrder, mode);
delay(10);
}
}
}
void chat(SPIFrequency frequency, uint32 bitOrder, uint32 mode) {
SerialUSB.print("Having a chat.\tFrequency: ");
printFrequencyString(frequency);
SerialUSB.print(",\tbitOrder: ");
SerialUSB.print(bitOrder == MSBFIRST ? "MSB" : "LSB");
SerialUSB.print(",\tmode: ");
SerialUSB.print(mode);
SerialUSB.print(".");
SerialUSB.print(" [1] ");
alice.begin(frequency, bitOrder, mode);
SerialUSB.print(" [2] ");
uint32 txed = 0;
while (txed < TEST_BUF_SIZE) {
ASSERT(alice.transfer(test_buf[txed]) == test_buf[txed]);
txed++;
}
SerialUSB.print(" [3] ");
alice.end();
SerialUSB.println(" ok.");
}
void soliloquy(SPIFrequency freq, uint32 bitOrder, uint32 mode);
void soliloquies(uint32 bitOrder) {
for (int f = 0; f < NFREQS; f++) {
for (int mode = 0; mode < 4; mode++) {
soliloquy(spi_freqs[f], bitOrder, mode);
}
}
}
void soliloquy(SPIFrequency frequency, uint32 bitOrder, uint32 mode) {
const uint8 repeat = 0xAE;
SerialUSB.print("Alice is giving a soliloquy (repeating 0x");
SerialUSB.print(repeat, HEX);
SerialUSB.print("). Frequency: ");
printFrequencyString(frequency);
SerialUSB.print(", bitOrder: ");
SerialUSB.print(bitOrder == MSBFIRST ? "big-endian" : "little-endian");
SerialUSB.print(", SPI mode: ");
SerialUSB.println(mode);
alice.begin(frequency, bitOrder, mode);
while (!SerialUSB.available()) {
alice.write(repeat);
delayMicroseconds(200);
}
SerialUSB.read();
}
void printFrequencyString(SPIFrequency frequency) {
switch (frequency) {
case SPI_18MHZ:
SerialUSB.print("18 MHz");
break;
case SPI_9MHZ:
SerialUSB.print("9 MHz");
break;
case SPI_4_5MHZ:
SerialUSB.print("4.5 MHz");
break;
case SPI_2_25MHZ:
SerialUSB.print("2.25 MHZ");
break;
case SPI_1_125MHZ:
SerialUSB.print("1.125 MHz");
break;
case SPI_562_500KHZ:
SerialUSB.print("562.500 KHz");
break;
case SPI_281_250KHZ:
SerialUSB.print("281.250 KHz");
break;
case SPI_140_625KHZ:
SerialUSB.print("140.625 KHz");
break;
}
}
// Force init to be called *first*, i.e. before static object allocation.
// Otherwise, statically allocated objects that need libmaple may fail.
__attribute__((constructor)) void premain() {
init();
}
int main(void) {
setup();
while (true) {
loop();
}
return 0;
}
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