hi,

On 07/23/2014 03:02 AM, dougall wrote:

Hi,

Thanks for your great tutorial on writing Puredata externals. It had me up and running in no time.

great to hear

I found a small bug.The pan~ example code doesn't assign the pan_tilde_free function pointer in the pan_tilde_setup function. It is explained clearly in the document but the example code itself doesn't match.

thanks, i'll fix it asap.

Perhaps you can answer a question for me. I've been writing some externals to read data from analog sensors on an i2c device. I have a separate thread and use sys_lock() and sys_unlock() to output to the data to pd from inside the thread. Is this best practice? I've seen a number of different approaches to this situation.

first of all, the best place to ask such questions is the pd-dev mailinglist [1].

imho, the best practice is:

• setup a clock-callback that converts the data from your representation

to an atom-list and then outputs the data.

• in your reading thread trigger the clock in a protected way:

  sys_lock(); clock_delay(x->x_clock, 0); sys_unlock();

• this will call the clock asap within the main thread of Pd.

fmadsr IOhannes

[1] http://lists.puredata.info/listinfo/pd-dev