DEV Community

Cover image for Day 6: This multi-blog post, processing

Day 6: This multi-blog post, processing

Ok, before I dropped off to sleep, I found the following article which is pretty much what I need to connect arduino to processing and have them sending data between them.

  • board -> processing : data from accelerometer
  • processing -> board : bitmap image generated from accelerometer data

So that's today's goal, at least get processing picking up data from accelerator.

Before that happens, a little side-track

I wanted to see if I can get the accelerometer data in m/s instead of the raw data, and print it to the TFT.

Here's the bit of code that retrieves the data in m/s^2


Enter fullscreen mode Exit fullscreen mode

I set the background of TFT to be black (ST77XX_BLACK).

Now when I write to the TFT, the text just writes on top of each other makine a mess after awhile. Did a little search on refreshing text on TFT, and all I needed to do was print the text with its text colour plus the background colour (in this case is black).

tft.setTextColor(color, ST77XX_BLACK);
Enter fullscreen mode Exit fullscreen mode

Saved, compiled and uploaded the code and that did the trick.

Also played around setting the text size, if you are curious, this is what I used:


Enter fullscreen mode Exit fullscreen mode

Now I have my data in m/s, let's get processing talking to it

I'm going to initially send over the X value.

Created my processing code and got this exception

RuntimeException: Error opening serial port /dev/cu.usbmodem14101: Port busy
Enter fullscreen mode Exit fullscreen mode


Over lunch I asked Mick that I couldn't connect to the serial port via Processing. He mentioned if I closed my Arduino IDE. đŸ˜ŗ

Yep, very DOH! moment there.

So after lunch I closed Arduino IDE, modified the code on Processing a little and lo and behold... it worked!

Alt Text

Ok, I can read text, I want to read values now.

Before I do that, I'm ditching my PyProcessing code from before and changing to pure Processing now.

So do the same thing (easily replicated from the official tutorial docs drawing the grayscale image), and I wanted to save() the image as bitmap and exit() the programme, which was all fine.

Now I was looking at drawing simple shapes and lines, and have it randomised (colours between 0 and 255) and the X/Y co-ordinates in-between 240x240.

After a bit of reading through shapes and PShapes, I stuck with primative shapes, I wanted lines and various sized ellipses in various colours generated before the time lapses and gets saved to a bitmap file.

Here's a sample of the generated bitmap from Processing:

Alt Text

Top comments (0)