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watterott / CO2-Ampel

CO2-Ampel / CO2-Traffic-Light to measure and show the carbon dioxide concentration in a room, based on Sensirion SCD30/SCD4x sensor and Microchip SAMD21 microcontroller
https://learn.watterott.com/breakouts/co2-ampel/
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No values detected on serial link until I flashed the v10+ firmware #7

Closed olberger closed 3 years ago

olberger commented 3 years ago

Is there a known issue (undocumented ?) on standard device which could become silent over serial ?

I seem to had proper serial config with cutecom and /dev/ttyACM0 (9600, 8-N1 etc.) but couldn't detect anything on the serial line. Leds were working fine (supposedly, changing to green when getting fresh air, etc.)

After I flashed the v11 firmware, it suddenly started to report sensor values.

Also I couldn't figure out how to detect which version of firmware was running initially as shipped from the store... but that's probably another issue ;-)

awatterott commented 3 years ago

With v10 the USB detection was changed and previously flow control was used via Arduino Serial functions, which only works directly with the Arduino IDE. https://github.com/watterott/CO2-Ampel/blob/master/arduino/samd/libraries/CO2-Ampel/examples/CO2-Ampel/CO2-Ampel.ino#L1284 There is currently no command to receive the version of the firmware.

olberger commented 3 years ago

Uh, sorry but I fail to understand if the above response is supposed to explain why I couldn't see any traffic on the USB serial... Could you explain for someone without knowledge of Arduino stuff ?

awatterott commented 3 years ago

If the firmware/CO2-Ampel does not detect a USB host device, then no data will be sent via the USB serial port.