manitou
Senior Member+

Yay! SCK to GND solved it! The two raspberry pi forum articles I had both had SCK unconnected. sigh. many thanks

I have tried 3v3 and 5v, and behavior is the same. I even tried DC power jack on ZERO instead of USB power. Still misbehaves.

EE help needed for I2S DAC. I have successfully tested adafruit I2S DAC UDA1334A, with Teeeny 3.2/3.6/4.0 and Arduino ZERO. Tested sine wave with ear-buds and scope to DAC line out. DAC is wired with (3v3, GND,...

as my example shows (and the reference manual dictates), you must "set" the status bit to clear it.

you need to clear the interrupt flag in the ISR, otherwise the interrupt will fire again as soon as you exit the ISR ... the black hole. you also need asm volatile ("dsb"); in the isr to keep ISR from firing twice.. ...

The pins that T4 GPT uses are defined in table 52-2 of the reference manual. Look at the T4.0 and T4.1 schematics to determine which pins are actually available for the teensy PCBs. You'll need...

Using rpi pico, I've run some circuitpython/micropython tests and run a few C benchmarks via cmake and SDK (-O3 gcc 6.3.1). Here are some coremark plots Compile options iterations/sec @125MHz, -Os 144.606175,...

The T4 configures the GPT and PIT to clock at 24mhz, if you configure for 150mhz it will break the interval timer (PIT). here is example of GPT running at 150mhz...