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Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   Over the weekend the remaining parts arrived and I finished populating the board.  I found a few more problems and will document them here.  Normally I don't document problems unless they are somehow unique and instead give the final state but for this project I am going to publish warts and all.   Here is the populated board next to a dAISy receiver.& ...
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   The PCBs arrived today but unfortunately I was slow in ordering the more obscure parts for the design and they have not yet arrived.  This blog post will describe populating the board with the parts I have on hand and first impressions of what will be needed for the next revision.   Here is a photo of the board as it currently stands: It looks pretty spa ...
Last summer my 5 year old grandson spent the week with me and I promised his mother it would be educational and him that it would be fun.  Early in the week we wired up LEDs, beepers and switches, learned about polarity, etc.  We played with a simple robot that could be programmed to run a route.  I kept it to only a couple of hours a day and allotted  time to do other stuff.  The highlight was a project we did at the end of the week.   My objective with the projec ...
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   With the schematic complete it was time to design a PCB.  This blog entry will outline the PCB design and layout along with the primary considerations. The "L" shape of the PCB is a direct result of the enclosure that will be used and is necessary to avoid interference with other components already inside the case.  The dAISy radio receiver will reside un ...
fmilburn

AIS Alarm - Schematic

Posted by fmilburn Top Member Jan 12, 2018
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   The breadboard prototyping and first pass at firmware are sufficient to proceed to hardware design.  After exchanges with the developer of dAISy and some early layout I have modified the pins used by the microcontroller and foresee the need to refactor the firmware.  At this point though no show stoppers are foreseen.  This post will describe the prelim ...
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   The prototype now receives AIS messages from the dAISy module and stores them in a persistent FRAM ring buffer.  The ring buffer will be described in this post and code to test the concept by emptying the ring buffer and displaying it implemented.   The ring buffer uses an algorithm presented by Jack Ganssle in Embedded Muse 110 and published in 2005.  I ...
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   The prototype now receives AIS messages from the dAISy module and stores them in a persistent FRAM ring buffer.  My intention today was to test the ring buffer but I discovered lots of bounce with the button used to push the buffer contents to UART.  This post will outline a software debounce scheme that makes use of the millisecond counting ISR already in t ...
Project Objective: Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range   The prototype is now receiving AIS messages from the dAISy module.  In this post a method for storing the messages in a persistent FRAM ring buffer will be described.  This is important to the project because persistent storage means the messages will not be lost when the device is unplugged from power.   The screen shot below taken from the CCS debug vi ...