Alexander Knochel on Nostr: My problem is that the Micro:Bit serial output does not seem to sink enough current ...

My problem is that the Micro:Bit serial output does not seem to sink enough current to pull the LoRa Board RX down to 0V. The same module works when driven by a Raspberry Pico (shown on oscilloscope). Does the micro:bit have such a high output impedance, or the Seeed Wio E5 such small pullup resistors?