Week 13: NETWORK COMMUNICATIONS
This week for HTM(A)A, our task was to build a wired &/or wireless network with at least two nodes. Given the fact that I have a ton of finals to worry about, I decided to stick with the basic Bus demo and learn from that.
The way it works, is that you have a main board (bridge), and then several accompanying boards (nodes). The main board communicates to the computer via serial FTDI/USB. A user can send a "1" in a serial monitor interface, and all boards should blink their LEDS, but Node 1 should blink twice. "2" would do the same but make Node 2 blink twice. Etc
As you might of guessed by the confused monkey metaphor, I failed at this task like a confused monkey metaphor.
To save time I combined all three boards into one traces / outlines file. This way I don't have to constantly be changing end mills. Feel free to download the png's, they're full size!
Sorted the components while these bad boys were cutting.
So.. during literally the last 5 seconds of cutting out Node 2, the double sided sticky tape got loosened upwards, causing the 1/32" endmill to scrape across a portion of the board and mess up some of the traces..great!
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Luckily thanks to Seto's extra board, I didn't have to remill the node.
Stuffing went fine.We did not have or 2 x 2 6 pin headers available in the Arch Fablab..so we made due with reusing materials from old boards and 2 x 3 headers.
Programming went good! No problems. I thought the rest was going to be cake, right? Wrong!
For some reason I could not get Linux, Mac OS X, or PC to pick up the usb port from the ftdi cable. The light from the main bridge device might (at first plug-in ) turn on, but then quickly shut off . I could not get past this step, where you would grab the usbserial ID to talk to the device via term.py. All that it would say is:
"No such file or directory".
The crazy thing is that I had it working fine in inputs week, by following Kelly Shaw's tutorial (from previous year) on getting pyserial to run on mac os x. Both me and Manto had this issue. Looks like I'll have to waive the white flag on this one. My guess is one of the following, but what do I know..check below for the error screenshot as well.
- Too much power is being drawn from the usb, causing system to shut down the port
- Not enough power is being withdrawn, port is not recognized.
