pin tests
I ran various pin tests on edge pins, digital out, in,INPUT_PULLUP, analog in, pwm out, attachinterrupt . Most things are OK, but i had two
anomalies.
1) nothing on pin 9 for PWM ??
2) A3 sees 3v3 ok, but to GND, reads 1021 and not 0 ????
EDIT A3 is pin 17 which is used by core printf,
ok.
Most MCU's with floating input to analog input read "random" values, T4 floating analog are pretty steady... FWIW
Measured internal INPUT_PULLUP resistors at about 23K ohms.
Pin 13 in INPUT_PULLUP mode measures 1.68v as a result of resistor-LED on pin 13.
EDIT: pin 9, me thinks definition is wrong in
hardware/teensy/avr/cores/teensy4/pwm.c, pins 8 and 9 have same config??
Code:
{1, M(2, 2), 1, 2}, // FlexPWM2_2_A 8 // B0_10
{1, M(2, 2), 1, 2}, // FlexPWM2_2_B 9 // B0_11
FIX: change to
{1, M(2, 2), 2, 2}, // FlexPWM2_2_B 9 // B0_11
and pin 9 PWM works
EDIT: 2nd beta unit, all edge pin tests OK 1/10/19
With T4 breakout board (1/15/19) confirmed backside pins worked, digitalIO worked, PWM worked (no waveform inversion), and Serial 1-8 worked Rx-to_Tx