Features under Test

Feature under test FUT_TIMER

Test proposals
- Clock dividers, timers
  - stimuly: TENTACLE_MCU generates pulse or PWM on SIGNAL_TRIGGER1/2.
  - expected: TENTACLE_DAQ_SALEAE verifies this pulse.

Feature under test FUT_I2C

Electrical setup
- Exacly one TENTACLE_MCU connects to SIGNAL_DATA1/2.
- Exactly one TENTACLE_DEVICE_POTPOURRY connects to SIGNAL_DATA1/2. This tentacle must provide the I2C pull ups.
Test proposals
- Datatransfer
  - stimuly: TENTACLE_MCU acts as a I2C-controller and the TENTACLE_DEVICE_POTPOURRY as a I2C-target.
  - expected: meaningful data
- Errors
  - See comments below

Feature under test FUT_UART

Electrical setup
- Exacly one TENTACLE_MCU connects to SIGNAL_DATA1/2 and SIGNAL_TRIGGER1/2.
  - The TX pin of TENTACLE_MCU / TENTACLE_DEVICE_POTPOURRY requires a serial 1k resistor. This allows the TENTACLE_DAQ_SALEAE to destroy the signal.
- Exactly one TENTACLE_DEVICE_POTPOURRY connects to SIGNAL_DATA1/2.
Test proposals
- Timing test sequence:
  - stimuly:
    - TENTACLE_MCU: SIGNAL_TRIGGER1 low->high
    - TENTACLE_MCU: SIGNAL_DATA1 send 3 characters
    - TENTACLE_MCU: SIGNAL_TRIGGER1 high->low
  - expected:
    - This tests allows various timing aspects. For example [uart.flush()](https://github.com/micropython/micropython/issues/13377)
  - variants:
    - Test hardware UART vs software UART.
    - Test syncio vs asyncio.
- Errors
  - See comments below

Feature under test FUT_ONEWIRE

Electrical setup
- Exacly one TENTACLE_MCU connects to SIGNAL_DATA1.
- Exactly one TENTACLE_DEVICE_POTPOURRY connects to SIGNAL_DATA1. This tentacle must provide the onewire pull up.
Test proposals
- OneWire scan without response
  - stimuly: TENTACLE_MCU: scan for sensors. No sensor is connected by opening the ONEWIRE relay and closing the I2C-SCL relay.
  - expected: No response after some timeout.
- OneWire scan
  - stimuly: TENTACLE_MCU: scan for sensors.
  - expected: 2 sensors found.
- OneWire communication
  - stimuly: TENTACLE_MCU: reads serial number from one sensors.
  - expected: serial number
- OneWire communication with error
  - See comments below

Feature under test FUT_I2C/FUT_UART/FUT_ONEWIRE: Communication errors

Test proposals
- Recovering from errors
  - stimuly: I2C/UART/ONEWIRE communication. Now TENTACLE_DAQ_SALEAE tentacle overrides SIGNAL_DATA1/2 to provoke errors.
  - expected: Error and recover.
  - challenge
    - How to introduce errors without introducing flakyness?
    - How to provoke data integrity errors (CRC)?
    - How to provoke protocol errors (timeouts, start/stop bit missing)?

How to electrically override SIGNAL_DATA1/2:

I2C/ONEWIRE: SIGNAL_DATA1/2 are pulled up. TENTACLE_DAQ_SALEAE may just override these outputs.

UART: The TX-signals outputs have low impedance. A serial 1k resitor is added (see TENTACLE_MCU_x/TENTACLE_DEVICE_x) which then allows TENTACLE_DAQ_SALEAE to override both TX-signals.