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[POTM] dAISy - A Simple AIS Receiver

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Have you consider using Molex's Eurostyle 39501 and 39502 series connectors? (search on eBay for 3.5mm pluggable screw terminal block connector)

 

What's the status of dAISy BoosterPack?

 

Thanks for the Molex SKUs and Ebay query. 3.5mm terminal blocks look like a very common, standardized format with plenty of cheap options from various vendors.

 

The BoosterPack is a bit on the back burner right now. While it's nice as a breakout for the Si446x family of radio ICs, using it is pretty complex, particularly if you want to do more than just replicate dAISy on a F5529 LaunchPad.

 

I'm thinking about adding a G2553 onto the BoosterPack to abstract away the receiver part. Then an Energia library could receive the AIS messages via serial (or I2C??) and provide more convenient interfaces to build applications on top.

 

Also thinking about more popular form factors, e.g. a RasPi Hat or Arduino Shield.

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I didn't think about using NAND gates as an inverter. Good alternative to the transistor solution above.

 

Re Bluetooth, I guess your idea is to use 2 Bluetooth modules, UART serial on dAISY's side and RS232 on the NMEA device side.

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I did it(first step). Example "WiFiTelnetToSerial" is a good platform for this purpose. ESP-01 - 3.3V 50 mA.

PS GPS is connected directly to ESP-01. OpenCPN shows where I am situated by wifi (192.168.1.42:23).

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ESP01 consumes too much current. So WiFi is good but USB is better.However,

 

I made upgrade NASA ENGINE3. I inserted the GPS shield with 9600 baud and the Arduino nano (for chenging 9600 to 4800) in ENGINE3. ENGINE3 can insert GPS string with 4800 in 34800 ENGINE3 sending by COM port. I inserted step down converter 12V->3.3V and ESP01 in ENGINE3. ESP01 sends summary signal in WiFi telnet port (23). So there is a new ENGINE3. 

 

 

NEW .................If to add  GPS shield we can get a alarm device of dangerous closing.... It`s a alarm device of dangerous closing (module with generic  STM32f103c8).  (12V 150 mA)

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Find code for dAISy and the TMC123G and F5529 LaunchPads with a CC3100 BackPack to send data to MarineTraffic using Energia here: https://github.com/fmilburn3/dAISy_marinetraffic

 

Note that for the F5529 it is necessary to increase the serial ring buffer size in Energia (HardwareSerial.cpp) to get stable operation, e.g. #define SERIAL_BUFFER_SIZE 512.  The TMC123G runs without any modifications to Energia.  It should also work with the CC3200 although I haven't been able to test it with this latest version of the code.

 

And here is a screen capture...

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Hi!

 

First i need to thank you for your excelent work! It is amazing!

 

Now to my question. I'm interested in building a dAISy by myself. You made much efforts in optimizing dAISy, but the published schematics are two years old. So i would like to kindly ask, if you could update the schematics in the github project. I would be so thankful.  :)

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@@pppt Yes, I should post at least the schematic of my BoosterPack on GitHub. I simply didn't have time yet to also adapt the published code to support it. But I'm happy to share what I have in private. I will send you a PM.

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By the by, a friend just pointed out another chip family that might be coaxed into receiving/transmitting AIS.

 

The Spirit1 by ST covers the right frequency range. It is also significantly cheaper than the SiLabs Si446x family, at least in volumes > 100 pcs. Good availability, Mouser and Digi-Key have stock.

 

Not sure how well it would cope with the non-standard preambles that AIS has due to the NRZI encoding scheme.

 

http://www.st.com/web/en/catalog/sense_power/FM1968/CL1976/SC1845/PF253167#

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Hi, it's a great project. I'm interested in making my own AIS receiver too, but can you tell me why do we need to use the decoupling capacitors and the 220pF capacitor before the LNA?

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@@meynarddanam Apologies for the slow response.

 

Which 220pF capacitor or what part of the circuit are you referring to?

 

I was experimenting with a separate LNA here:

http://forum.43oh.com/topic/4833-potm-daisy-a-simple-ais-receiver/?p=53200

 

But in the end it didn't make a difference, or was even counterproductive. The radio itself is very sensitive and the main challenge is to keep interference from unwanted frequencies down.

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@@meynarddanam Apologies for the slow response.

 

Which 220pF capacitor or what part of the circuit are you referring to?

 

I was experimenting with a separate LNA here:

http://forum.43oh.com/topic/4833-potm-daisy-a-simple-ais-receiver/?p=53200

 

But in the end it didn't make a difference, or was even counterproductive. The radio itself is very sensitive and the main challenge is to keep interference from unwanted frequencies down.

the one after the antenna? It's not part of the LNA, is it? and why do we need to use decoupling capacitors after the power supply?

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You will have to post a picture or a link to what circuit you're referring to regarding the 220pF capacitor.

 

The are decoupling caps near the radio IC to remove noise from the power rail. That's good practice and implemented as recommended in the radio's datasheet or a related app note.

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