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chicken

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Everything posted by chicken

  1. Hi Sven, I think the MSP430 side is ok. It looks like your setup is able to configure the radio, and something is received. Sync indicates, that the packet handler ISR found preamble and start flag. Did you already try the regular branch? The 4463 branch is quite stale, and it looks like I did a few changes to radio configuration and packet handler on master after the branch. Regards, Adrian
  2. Yes, message type 24 is supported. dAISy itself is not really aware of the AIS message contents. It will forward all valid AIS messages it receives. You may see fewer Class B messages than expected because: Class B transponders are much weaker than Class A, and therefore more prone to noise interference. Especially for long messages like static data. Class B messages are typically sent less frequently than Class A
  3. Happy to hear that, and thank you for the review on Tindie! I had to lookup how a Jon boat looks like With that low height, I'm surprised of the 7 miles range.
  4. Here's something new in the "I would like to play with that" category: A pico-projector in the form factor of a BeagleBone Black cape. At $99, the price isn't too bad either. http://www.ti.com/tool/dlpdlcr2000evm#0
  5. @nazmibojan your radio IC may be toast by now, so you may have to replace it. @longjohn119 thank you for the detailed report. My own knowledge about antennas is very basic. It's definitely much noisier around here in suburban Seattle. Also always interested how the receivers compare to SDRs, as basically it's a very specialized SDR. For a fairer comparison, you could try to add a bandpass filter in front of the SDRs. My 1-channel dAISy has a discrete LC filter built from SMT components, and it holds up surprisingly well to the SAW filter used on other models. In real world tests
  6. I usually have the check for the CCA condition turned off as well. It only did make sense for single-channel receivers where RSSI level can be used for more intelligent channel hopping (didn't make much of a difference). I still suspect noise to be your main issue.
  7. Excessive power would be my guess if the receiver doesn't work anymore. The radio IC is only rated to an absolute max of 10 dBm, equivalent to 10mW. You can somewhat protect the radio with two parallel PIN diodes from RF to ground. One with cathode to GND and the other the opposite way. This clamps the signal to a maximum of less than +/- 0.7V, the equivalent of 10dBm. Though not sure how long that would help when directly connecting the receiver to an AIS transponder.
  8. Hi Rian, Is this repeatable? I.e., when you reboot dAISy it works again for a few minutes?
  9. Regarding your range problem: I program the firmware on my HATs with the debugger on the MSP430F5529 launchpad. If I don't power cycle (unplug and reconnect USB) after programming and before testing, I see elevated noise levels. I don't know the exact reason, but suspect that the JTAG traffic on USB introduces noise. Maybe there's a similar issue with the Discovery boards.
  10. Hmm, it's a while since I looked at it in detail. Channel spacing is 50KHz. If I remember correctly, bandpass was set to 20 or 15KHz. I stay away from building a transponder as there's a real risk of disrupting AIS traffic if done wrong. But if you want to go down that avenue, check out this project: https://github.com/peterantypas/ais_transponder
  11. I apologize for the slow response. Besides configuration, severely limited range can be a noise issue. You may introduce noise to the radios with the wires connecting over to the STM32. The radio_config.h for the Si4362 should be a good starting point as the EzRadioPRO chips are compatible. You can generate the radio_config files for the Si4467 with the WDS tool from Silabs: https://www.silabs.com/products/development-tools/software/wireless-development-suite Seems like they changed the file format since the last time I used it. The attached project file can be loaded with
  12. Hi John, Quite an impressive setup you have here. I will have to dig through your blog when I have more time. As for your questions: You are correct, the HAT can be run standalone and connected to a PC with a FTDI cable. You also can power the HAT over USB by connecting the respective wire to a 5V pad on the HAT. Serial 1 duplicates the connection that goes to the Raspberry Pi and you can connect it to any other "host" device, including an Arduino. The baud rate of Serial 1 is fixed to 38400 baud. And you are also correct regarding the I2C header. It's a straight breakout o
  13. Look at the pinout in the datasheet. With the G2553, TAxCLK is only available on P1.0. I compiled a table for a few MSP430s for my CounterLib here: https://github.com/astuder/CounterLib-Energia/blob/master/README.md
  14. Good progress and tidy prototyping. Interesting observation about the beam being too narrow. I wouldn't have expected that problem with bare LEDs. Angling will be tricky without visual verification.
  15. That's a nice mock-up. Took me a while to realize that the keypad and display just sit on top of a tin box.
  16. Hi Jens, The breakout while primitive will work as well as the Si446x modules from Ebay/AliExpress. Both will get you started if in line of sight of AIS targets. But I should publish the BoosterPack sometime and update the Github project accordingly. The bandpass filter increases the number of messages received. Range can be better or slightly worse depending on your RF environment. The Si4467 does perform better than the older gen chips (e.g. Si4362-B1B). In real world scenarios the difference can be minor to significant, depending on how marginal AIS reception is. I
  17. Now here's a set of fancy booster packs! It's a fully integrated automotive radar. http://www.ti.com/lsds/ti/sensing-products/mmwave-sensors/awr/awr-tools-software.page#tools Those rectangles on the right with wiggly traces to the IC are the radar antenna. RF magic! The "CAUTION HOT SURFACE" warning label also promises excitement. Too bad they will cost $299 according to the press release. Posting in the ARM sub-forum as the radar IC features an R4F ARM core. Though the booster packs probably work with beefier MSP430 LaunchPads too. Edit: Here's the mmWave la
  18. For a bit of background: Atmel AVR (the chip in the original Arduino) has a Harvard Architecture, which separates program memory (i.e. Flash) from data (i.e. RAM). It uses special assembly commands to read program memory. That's why you need to tell the compiler if you want to store a variable in Flash or access data that's stored in Flash. Most other MCUs have a Von Neumann architecture with a unified address space for all types of memory. All access to memory can use the same commands and the compiler decides on where to put things, depending on whether a variable is read-only (Fla
  19. Unless you care about portability to Atmel Arduinos, there's no need to use progmem with Energia. The compiler will put anything that's declared as const into flash memory.
  20. Depending on you environment NULL may not be defined. You can use 0 as alternative. E.g. if ( bar == 0 )
  21. I guess the forward diode is to bypass the 10k resistor when the MCU draws more than 70uA. That's a great trick to remember.
  22. Hi @wanliban Datasheet numbers are hard (impossible?) to hit, especially when the signal comes from a real world target rather than a piece of lab equipment. But you should definitely be able to achieve better than -70 dBm. First thing: What does -70 dBm mean in your setup? The level at which you are able to receive any valid messages? Level at which you receive 50% of all messages? 80%? Real world targets or controlled signal from an RF generator? You can find my radio_config file and software on GitHub: https://github.com/astuder/dAISy Hardware wise, keeping noise out is
  23. I wonder if there's some aggressive compiler optimization going on. The compiler wouldn't know what's happening inside the ROM functions and may put function calls out of order. Maybe worth a try to see if it works with straight calls to the driver lib (i.e. dropping the MAP_ prefix). PS: The reference manual says, that CRC result is available after 1 clock cycle. Also no mention of CRC issues in the errata.
  24. I don't try to convince anybody. I'm way too busy myself to unlearn bare metal C. But I thought the video will be relevant for people that venture down the rabbit hole.
  25. Here's some more C++ magic which seems applicable to embedded programming. I think he optimized for speed instead of space (using tons of mov instead of a loop to initialize sprite bitmaps). But a lot of impressive optimization by the compiler. On the downside, I didn't understand half the constructs he was using. I guess I need to relearn C++ via embedded.fm podcast
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