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Design flaws
12/19/2014 at 05:21 • 0 commentsI have discovered a few problems with the MDM board. 1. Missing pull up on tx out pin on the rs485 driver. I discovered that when the ~re (receive enable) pin on the 485 driver goes high, the tx out pin goes low. This high to low transition will appear as a start bit and cause a character interrupt on the xmega. By pulling up th tx out pin the line will stay high when the receiver is turned off. 2. The chip select lines for all six motor drivers are connected together but are not connected to the xmega. -
Board testing
12/13/2014 at 15:21 • 0 commentsI finally got around to building up the MDM board. I populated 1 motor driver IC and the rs485 driver. I had a problem where the package I used from Kicad for my Atxmega was too small so I had to create another Atxmega break out PCB and wire that to the original MDM board. Long story short I have lab view on the PC sending messages via rs485 to the xmega which is driving PWM to the motor driver that drives the motor with a propeller attached. The motor draw less than an amp at full speed when unloaded and about 3 amps when submerged in water. -
MDM PCB
09/12/2014 at 03:22 • 0 commentsI got the MDM PCB from OSH Park a couple of weeks ago. I started to assembly the board tonight, but I relized that the ATXMEGA128D3 was too large for the footprint I had put on the board. I selected the TQFP64 footprint from Kicad, but didn't verify the dimensions against the data sheet.
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System Design Diagram
08/20/2014 at 04:23 • 0 commentsThis diagram shows the ArduSub connected to the Internet, on-board electronics, sensors and thrusters.
https://github.com/HoferTech/ArduSub_Docs/blob/master/Docs/system_diagram.pdf?raw=true
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Entry Video
08/20/2014 at 04:17 • 0 commentsUploaded entry video. It was very hard to describe all the details I wanted in two minutes. I did manage to show the board from KiCAD 3D viewer in luie of waiting for my board to ship.
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PCBs
08/17/2014 at 13:42 • 0 commentsMDM pcb is on its way should be here on Monday. Working on code, I wanted to demo board for my entry video but I don't think I will have enough time.
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MDM Hardware Block Diagram
08/09/2014 at 16:49 • 2 comments -
ArduSub Communication Spec
08/09/2014 at 15:30 • 0 commentsWorking on this document, describes the messages that go from one board to another. Will post soon.
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PCBs
08/09/2014 at 15:01 • 0 commentsI ordered the MDM PCB from OSH Park 3 copies of the MDM for $80.15.
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08-07-2014 3:20 PM
08/07/2014 at 20:20 • 0 commentsAdded MDM Gerbers
ArduSub
A solar powered autonomous submarine that explores and measures the ocean at night, and posts the results to Twitter and Facebook by day.