timer-log.py

import machine, utime
log = []
def add_log(t):
    global log
    log.append((utime.ticks_us() & 0xffffffff) + 1000 - t.compare_register())

times = 1000
tim = machine.Timer(3)
tim.init(period=1000,mode=tim.PERIODIC,callback=lambda t:add_log(t))

while(tim.counter() < times + 1):
    pass

tim.deinit()

for i in range(min(log),max(log) + 1):
    print(i, log.count(i))