RP2040 USB HOST CDC

Hello all,

I am working with raspberry pi pico, rp2040, in HOST CDC mode, using the reference "host_cdc_msc_hid" project (without the msc and hid), I validate it mounts another microcontroller in device CDC mode.

Callbacks for mounted and unmounted work perfectly while debugging, and sending data from HOST to DEVICE is ok too.

My problem is when reading data coming from Device CDC, when I checked the buffer variable with function "tuh_cdc_read" it is always empty. Also, the function "tuh_cdc_rx_cb" is never triggered which is weird ( and just to mention that even if I can send data from the host to the device, the "tuh_cdc_tx_complete_cb" is never triggered).

Any suggestions ?? or maybe I should enable any extra IRQ that I ignore, that is the final step to begin my project I will really appreciate the help. I am using TinyUSB library.

Thanks.

baldengineer over 2 years ago

Did you remember to call cdc_task(); in your main event loop?
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gabofienco over 2 years ago in reply to baldengineer

Yes, but something weird just happen, using stm32 (as device) and pico (as host) doesn't trigger the callbacks in the host RX and cdc_task() detects the mounted device in the conditionals (if......), but no data in the buffer with the read functions.

Now, I tested device/host with two PICOS, and I validate it works!, sending and receiving in both directions.

Does it make sense ? or stm32 has some restrictions or specific arguments when it comes to sending data to another device that makes it not compatible ??.. I though the problem was the rp2040 TinyUSB lib.

Thanks
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baldengineer over 2 years ago in reply to gabofienco

I think it is more likely an issue of how tinyUSB is implemented for a platform versus a hardware PHY issue.

It's a fantastic library, but the word "tiny" in the name means some shortcuts were taken.
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gabofienco over 2 years ago in reply to baldengineer

that makes sense, thanks for your feedback.
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