If you really need to print the values, you can use the standard Pd way of converting a signal to a message using [snapshot~], e.g.: you can connect each of them like this:
[loadbang]
|
[metro 50]
| [adc~ 3]
|/
[snapshot~]
|
[print]
However, on Bela you can use the Bela scope by sending a signal to dac~ channels 27-30 and visualise it in your browser:
[adc~ 3]
|
[dac~ 27]
Then open a browser tab at 192.168.7.2/scope to visualize the output while the patch is running