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Use new style SPI::beginTransaction() api, make SPI_CLOCK configurable, select hardware or software SPI based on SPI_CLOCK.

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This commit is contained in:
Peter Van Hoyweghen 2015-07-14 23:06:54 +02:00
parent 50f9e539d8
commit 89184a3668
1 changed files with 44 additions and 18 deletions
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62
build/shared/examples/11.ArduinoISP/ArduinoISP/ArduinoISP.ino
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@ -54,12 +54,32 @@
#define LED_PMODE 7
#define PROG_FLICKER true
#if !defined(ARDUINO_ARCH_SAM) and !defined(ARDUINO_ARCH_SAMD)
// Configure SPI clock.
// E.g. for an attiny @128 kHz:
// (pulseWidth should be > 2 cpu cycles, so take 3 cycles:)
// #define SPI_CLOCK (128000/3)
//
// A clock slow enough for an attiny85 @ 1MHz, is a reasonable default:
#define SPI_CLOCK (1000000/3)
// Select hardware or software SPI, depending on SPI clock.
// Currently only for AVR, for other archs (Due, Zero,...),
// hardware SPI is probably too fast anyway.
#if defined(ARDUINO_ARCH_AVR)
#if SPI_CLOCK > (F_CPU / 128)
#define USE_HARDWARE_SPI
#endif
#endif
#ifdef USE_HARDWARE_SPI
#warning hw spi !!!
#else
#warning NOT usung hw spi
#endif
// Configure the serial port to use.
//
@ -96,27 +116,34 @@ void pulse(int pin, int times);
#ifdef USE_HARDWARE_SPI
#include "SPI.h"
#define SPI_CLOCK_DIV_MAX SPI_CLOCK_DIV128
#else
#define SPI_CLOCK_DIV_MAX 255
#define SPI_MODE0 0x00
class SPISettings {
public:
// clock is in Hz
SPISettings(uint32_t clock, uint8_t bitOrder, uint8_t dataMode) : clock(clock){
(void) bitOrder;
(void) dataMode;
};
private:
uint32_t clock;
friend class BitBangedSPI;
};
class BitBangedSPI {
public:
void setDataMode(uint8_t dataMode) {
(void) dataMode;
}
void setBitOrder(uint8_t bitOrder) {
(void) bitOrder;
}
void setClockDivider(uint8_t clockDiv) {
(void) clockDiv;
void beginTransaction(SPISettings settings) {
pulseWidth = 1000 / (settings.clock / 1000);
if (pulseWidth == 0)
pulseWidth = 1;
}
void begin() {
// slow enough for an attiny85 @ 1MHz
// (pulseWidth should be > 2 cpu cycles, so take 3 cycles:)
pulseWidth = 3;
pinMode(MISO, INPUT);
pinMode(RESET, OUTPUT);
@ -148,10 +175,9 @@ static BitBangedSPI SPI;
void setup() {
SERIAL.begin(19200);
SPI.setDataMode(0);
SPI.setBitOrder(MSBFIRST);
// Select the slowest possible clock
SPI.setClockDivider(SPI_CLOCK_DIV_MAX);
SPI.beginTransaction(SPISettings(SPI_CLOCK, MSBFIRST, SPI_MODE0));
pinMode(LED_PMODE, OUTPUT);
pulse(LED_PMODE, 2);
pinMode(LED_ERR, OUTPUT);