Heya!

I'm trying to control different LEDs and PWM with a TLC5940 driver from PD. I'm trying to send strings of values from PD to Arduino via Serial port.
I'm using the comport object and attempting to pack values as shown below:
i.e.
s f s f s
%1,125/

However, it's not parsing on the Arduino side. I think it is because PD adds spaces in. I have tried to compensate for this with the start/end + delimiters on the Arduino side to no avail. Can anyone help me with regards to this? Or had similar problems and found a solution?

Cheers,

Joe

@louija Hello again.

I am sorry, I don't know much about comport, nor the Arduino. Some-one else will undoubtedly reply though. Here is your test patch with a test message at the right hand side.

raw.pd
Comport will not accept # at all
Comport will not accept your characters "joined up"
Comport will accept your characters separated by spaces and without the #

Good luck, David.

Can you post patch and Arduino sketch?

Thanks for all your help David. I'm trying sending messages with spaces and ending '\n' now.

Hello @alexandros have attached PD file and arduino sketch.

pd_joe.pd

test_data.txt

current_read_serial_sketch.ino

This was based on example Arduino code that reads an ASCII string with comma separated values.

The problem is that I can't find a way of sending to Arduino without commas etc. I have tried a number of parse example sketches (one that I successfully used years ago). I have attached this sketch here: pd_read_string_another_version.ino

Also, I am using an external library in Arduino (TLC5940) so not sure about using SMS?!

In ASCII '\n' is 10, which you can prepend to your lists, as Pd won't take \, I'm not sure if your approach will work.
I've made an abstraction that works with the Serial.parseInt() Arduino function. It's called [serial_parseInt] (not very original ) and you can get it here https://github.com/alexandros301/Arduino_println_parseInt_to_from_Pd along with some other abstractions for communication between Pd and Arduino. Let me know if it's helpful for you.

@alexandros thank you -this is very useful. Making good progress today. I have a single value parsing nicely. Will update with any challenges and results when I reach them. Thanks again, Joe.

@alexandros I have it working, but only for sending 2 values/bytes at a time, but for more than that it has a problem. I have attached my working code for any suggestions.

joe_arduino_working.ino
joe_working.pd -> this is using your serial_parseInt.pd abstraction

I'm controlling 2/16 LEDs at any one time so I need to send 4 bytes (LED no. and PWM). I can get away with sending three, as the LEDs fade: pwmVal2=255-pwmVal1.

Any other suggestions/work arounds are very much appreciated.

Thanks! Joe

but you're only making a list with two values, whereas you can make a longer list (with four or more values). Also, in your Arduino code, you're just parsing two bytes. Try to copy the for loop in the println_parseInt.ino Arduino sketch that comes with the [serial_parseInt] abstraction, so that you can get four bytes in Arduino. You'll need of course to make your list longer than that in the Pd patch..

hey @alexandros - sorry I am getting muddled. The one I posted is the working example using just one LED. If I add another value to the list and to the code in Arduino everything stops working. I have attached this below:

original_code_3.ino
pd_original.pd

I have tried the method as you suggested, but that is also not working. It turns the LED on but it gets stuck on and the PWM value doesn't seem to really change. I have attached that here:

arduino_println2.ino
puredata_println2.pd

Also here is the text file: text.txt

The only way I can get a smooth and reliable increase and decrease in PWM is from the patch+sketch in my previous post. But that only works with 1 LED. I have one more idea and that is to alternate the serial messages between the LEDs

i.e. instead of having 1 255 6
using:

1 255
6 255

I am going to try that now, but it does make my text file a little more complex to produce, but with it if it works. Thanks for all your help and guidance.

Thanks, Joe

I have just tried alternating the LED position number values in the txt file attached and using working code. The Arduino just seems to pick one LED and go with it. I tried adding an if != statement into Arduino but that just made random LEDs turn on. I don't understand what's going on!

text.txt

Just tried out the code with the patches, and put the [serial_print] abstraction to see if I can receive the values I send to the Arduino back to Pd.
This code arduino_println2.ino
works with this patch pd_original.pd
Though I had to slow down [metro] to 2000. The [serial_print] abstraction is in the same GitHub page, in case you didn't download it.
This shows that the values do go through to Arduino, and that most likely the Arduino code is not functioning.
Try this code with your patch arduino_println2_corrected.ino
I think that running a for loop was wrong, you were actually writing the values three times, and it might have been causing problems...