warpigs330
Active member
I am testing SPI with the teensy 4.1 with the goal of using the DAC7554 with it. I have not actually hooked them up together yet, as I have just been investigating the SPI signals from the Teensy. I noticed the fall time of the chip select seemed really slow compared to the clock and data, to the point where I would be surprised if it worked. I tried connecting to other pins and just pulling them low, and they all respond this way, even the pins that are currently sending clock and data.
Here is the script I am using, as well as an image from the oscilloscope.
Here is the script I am using, as well as an image from the oscilloscope.
Code:
#include <SPI.h>
int value1 = 0x8026;
int value2 = 0x0801;
int value3 = 0x8027;
int value4 = 0x0000;
void setup (void)
{
Serial.begin (9600);
Serial.println ("Starting");
digitalWrite(SS, HIGH); // ensure SS stays high for now
// Put SCK, MOSI, SS pins into output mode
// also put SCK, MOSI into LOW state, and SS into HIGH state.
// Then put SPI hardware into Master mode and turn SPI on
SPI.begin ();
// Slow down the master a bit
SPI.setClockDivider(SPI_CLOCK_DIV8);
} // end of setup
void loop (void)
{
// enable Slave Select
digitalWrite(SS, LOW);
SPI.transfer (1); // initiate transmission
SPI.transfer (11);
SPI.transfer (22);
SPI.transfer (33);
SPI.transfer (44);
// disable Slave Select
digitalWrite(SS, HIGH);
delay (1);
}