Limit PI-SPI-DIN 8AI SPI frequency to 100kHz

Author: optlink

src/pi_spi_din_8ai.c

@@ -1,25 +1,21 @@
 #include <spi.h>
-#include <wiringPi.h> 
-//#include <wiringPiSPI.h>
 
 #include "pi_spi_din.h"
 
+#define MAX_SPI_FREQ	100000
+
 uint16_t pi_spi_din_8ai_read_single(enum chip_enable ce, uint8_t channel)
 {
 	channel = channel > 7 ? 7 : channel;
 
 	uint8_t data[3] =
 	{
-		0x06 | (channel >> 2 & 0x01),
-		channel << 6 & 0xC0,
+		0x06 | ((channel >> 2) & 0x01),
+		(channel << 6) & 0xC0,
 		0
 	};
 
-	/*digitalWrite(chip_enable, LOW);
-	wiringPiSPIDataRW(0, data, 3);
-	digitalWrite(chip_enable, HIGH);*/
-	
-	spi_open(ce, 500000);
+	spi_open(ce, MAX_SPI_FREQ);
 	spi_transfer(data, 3);
 
 	return (((uint16_t)data[1] & 0x0F) << 8) | data[2];