@Roberthh: Thank you for your support!
I think it's time to use your logic analyzer
➝ I ordered an LA104, will take a week or so.
➝ I'll attend a hackerspace meeting tomorrow. Maybe I'll get learnings there.
With additional external power supply (EPS): stable 3.28V idle and during tests. However, results still depend on both, i2c frequency and i2c.status() poll delay. I resoldered the board pins: no improvement. I tried the spare PN532 board: same results.
PN532 test with connected EPS (
board 1):
Code: Select all
delay=0.40 (real:0.4167s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=50_000: [[36], [36], [36], [], [36], [36], [36], [], [36], [36], [36], []]
delay=1.60 (real:1.6667s) freq=50_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.2500s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=100_000: [[36], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=0.80 (real:0.8333s) freq=100_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.5833s) freq=100_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.2500s) freq=100_000: [[36], [36], [36], [], [], [], [], [], [], [], [], []]
delay=6.40 (real:6.4167s) freq=100_000: [[36], [36], [], [36], [36], [36], [36], [36], [36], [], [36], [36]]
delay=0.40 (real:0.4167s) freq=200_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=200_000: [[36], [], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.5833s) freq=200_000: [[36], [], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.1667s) freq=200_000: [[], [36], [], [], [], [], [], [], [], [], [], []]
delay=6.40 (real:6.4167s) freq=200_000: [[], [], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=400_000: [[36], [36], [], [], [], [], [], [], [], [], [], []]
delay=0.80 (real:0.8333s) freq=400_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.5833s) freq=400_000: [[36], [36], [], [36], [36], [], [36], [36], [36], [], [36], [36]]
delay=3.20 (real:3.2500s) freq=400_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=400_000: [[36], [36], [], [], [], [], [], [], [], [], [], []]
PN532 test with disconnected EPS, breadboard power supply board still mounted (3.27–3.29V during test,
board 1):
Code: Select all
delay=0.40 (real:0.4167s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=50_000: [[36], [36], [36], [], [36], [36], [36], [], [36], [36], [36], []]
delay=1.60 (real:1.6667s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.1667s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.5000s) freq=50_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=100_000: [[36], [36], [], [36], [], [36], [36], [36], [36], [], [36], [36]]
delay=0.80 (real:0.7500s) freq=100_000: [[36], [], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.6667s) freq=100_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.1667s) freq=100_000: [[36], [36], [36], [36], [], [], [], [], [], [], [], []]
delay=6.40 (real:6.4167s) freq=100_000: [[36], [36], [], [36], [36], [], [36], [36], [36], [], [36], [36]]
delay=0.40 (real:0.3333s) freq=200_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=200_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.6667s) freq=200_000: [[], [], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=3.20 (real:3.1667s) freq=200_000: [[36], [36], [], [], [36], [], [], [], [36], [], [], []]
delay=6.40 (real:6.4167s) freq=200_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=400_000: [[36], [36], [], [], [], [], [], [], [], [], [], []]
delay=0.80 (real:0.8333s) freq=400_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.5833s) freq=400_000: [[36], [36], [], [36], [36], [], [36], [36], [36], [], [36], [36]]
delay=3.20 (real:3.1667s) freq=400_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=400_000: [[36], [36], [], [], [], [], [], [], [], [], [], []]
PN532 test with disconnected EPS, breadboard power supply board still mounted (
board 1 resoldered):
Code: Select all
delay=0.40 (real:0.4167s) freq=50_000: [[], [36], [36], [36], [36], [36], [], [], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=50_000: [[], [], [36], [36], [36], [36], [36], [36], [], [], [], []]
delay=1.60 (real:1.6667s) freq=50_000: [[], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=3.20 (real:3.1667s) freq=50_000: [[], [], [36], [], [36], [36], [], [36], [], [36], [36], []]
delay=6.40 (real:6.5000s) freq=50_000: [[36], [36], [36], [36], [36], [36], [], [], [], [], [], [36]]
delay=0.40 (real:0.4167s) freq=100_000: [[], [36], [36], [], [36], [36], [], [36], [36], [], [36], [36]]
delay=0.80 (real:0.8333s) freq=100_000: [[], [36], [36], [36], [36], [36], [36], [36], [], [], [36], [36]]
delay=1.60 (real:1.5833s) freq=100_000: [[36], [36], [], [36], [36], [], [36], [36], [], [36], [36], []]
delay=3.20 (real:3.2500s) freq=100_000: [[], [], [], [36], [36], [36], [], [], [], [], [36], [36]]
delay=6.40 (real:6.4167s) freq=100_000: [[36], [36], [36], [36], [36], [36], [], [], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=200_000: [[36], [], [36], [36], [], [36], [36], [], [36], [36], [], [36]]
delay=0.80 (real:0.7500s) freq=200_000: [[36], [], [36], [], [36], [], [36], [], [36], [], [36], []]
delay=1.60 (real:1.6667s) freq=200_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [], [], []]
delay=3.20 (real:3.1667s) freq=200_000: [[36], [36], [36], [36], [36], [36], [], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=200_000: [[36], [], [36], [], [36], [], [36], [], [36], [], [36], []]
delay=0.40 (real:0.4167s) freq=400_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=400_000: [[], [], [], [], [], [], [], [], [], [], [], []]
delay=1.60 (real:1.5833s) freq=400_000: [[], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=3.20 (real:3.1667s) freq=400_000: [[], [36], [36], [36], [36], [], [36], [], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=400_000: [[], [], [], [], [], [], [], [], [], [], [], []]
PN532 test with disconnected EPS, but breadboard power supply board still mounted (3.31–3.35V during tests,
board 2):
Code: Select all
delay=0.40 (real:0.4167s) freq=50_000: [[], [36], [36], [36], [36], [36], [], [], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=50_000: [[], [], [36], [36], [36], [36], [36], [36], [], [], [], []]
delay=1.60 (real:1.6667s) freq=50_000: [[], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=3.20 (real:3.2500s) freq=50_000: [[], [], [36], [], [36], [36], [], [36], [36], [], [36], []]
delay=6.40 (real:6.4167s) freq=50_000: [[], [], [], [36], [36], [36], [36], [36], [36], [], [], []]
delay=0.40 (real:0.4167s) freq=100_000: [[36], [36], [], [36], [36], [], [36], [36], [], [36], [36], []]
delay=0.80 (real:0.8333s) freq=100_000: [[36], [36], [36], [36], [], [], [36], [36], [36], [36], [36], [36]]
delay=1.60 (real:1.5833s) freq=100_000: [[], [36], [36], [], [36], [36], [], [36], [36], [], [36], [36]]
delay=3.20 (real:3.2500s) freq=100_000: [[36], [], [], [], [36], [36], [36], [], [], [], [], [36]]
delay=6.40 (real:6.4167s) freq=100_000: [[36], [36], [], [], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.40 (real:0.4167s) freq=200_000: [[36], [], [36], [36], [], [36], [36], [], [36], [36], [], [36]]
delay=0.80 (real:0.8333s) freq=200_000: [[36], [], [36], [], [36], [], [36], [], [36], [], [36], []]
delay=1.60 (real:1.5833s) freq=200_000: [[36], [36], [36], [36], [36], [36], [36], [36], [36], [], [], []]
delay=3.20 (real:3.1667s) freq=200_000: [[36], [36], [36], [36], [36], [], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=200_000: [[], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=0.40 (real:0.4167s) freq=400_000: [[], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36], [36]]
delay=0.80 (real:0.8333s) freq=400_000: [[36], [36], [36], [], [], [], [], [], [], [], [], []]
delay=1.60 (real:1.5833s) freq=400_000: [[], [36], [], [36], [], [36], [], [36], [], [36], [], [36]]
delay=3.20 (real:3.2500s) freq=400_000: [[], [36], [36], [36], [36], [], [36], [36], [36], [36], [36], [36]]
delay=6.40 (real:6.4167s) freq=400_000: [[], [], [], [], [], [], [], [], [], [], [], []]
Same test with another I2C board show flawless i2c.scan() results, as expected (VCNL4040 proximity sensor):
Code: Select all
delay=0.40 (real:0.5000s) freq=50_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.80 (real:0.8333s) freq=50_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=1.60 (real:1.5833s) freq=50_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=3.20 (real:3.2500s) freq=50_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=6.40 (real:6.4167s) freq=50_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.40 (real:0.4167s) freq=100_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.80 (real:0.8333s) freq=100_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=1.60 (real:1.6667s) freq=100_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=3.20 (real:3.1667s) freq=100_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=6.40 (real:6.4167s) freq=100_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.40 (real:0.4167s) freq=200_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.80 (real:0.8333s) freq=200_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=1.60 (real:1.5833s) freq=200_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=3.20 (real:3.2500s) freq=200_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=6.40 (real:6.4167s) freq=200_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.40 (real:0.4167s) freq=400_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=0.80 (real:0.7500s) freq=400_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=1.60 (real:1.5833s) freq=400_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=3.20 (real:3.2500s) freq=400_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]
delay=6.40 (real:6.4167s) freq=400_000: [[96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96], [96]]