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Seeeduino Stalker v3.0 discussion

Home Forums Data Loggers Seeeduino Stalker v3.0 discussion

This topic contains 11 replies, has 5 voices, and was last updated by  Richard 2 years, 3 months ago.

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  • #1120

    Sam Atkins
    Participant

    Hi all,

    I am new to the wireless sensor world, and I had a question regarding the Seeeduino Stalker. I noticed while reading the blog posts that Mr. Hicks was staying away from the most recent iteration, v3.0, of the Stalker, and favored the previous version, v2.3, instead.
    As someone with a desk full of jumbled v3 stalker boards, sensor bits, and wifi chips, I’m curious if it will be worth my time to continue attempting to build sensors on this platform, or if they will be rendered un-usable in the near future.
    I remember reading a comment on seeeduino’s site mentioning that the v3 stalker uses more power in sleep mode than the v2.3, but I was wondering how much that would really impact sensor and wireless network performance. Thanks in advance for sharing thoughts and/or experiences.

  • #1127

    Shannon Hicks
    Keymaster

    The Seeeduino Stalker boards are handy because they are one of the few options on the market that have everything you need for a standalone, radio-reporting, solar-powered datalogger. I have been using them for about 4 years now, starting with a dozen of the v2.0 boards in 2011. They were okay, but there were issues with the supercapacitors used to keep the RTC alive, so I had to remove the caps and replace them with small lithium batteries. They also used an obscure RTC chip that didn’t have much library support or documentation. But one of the best features of the board was that the microSD memory card socket was mounted on the edge of the board, making it very easy to access the card, even when a shield was used on top of the Stalker. I still have some of these boards that are still deployed and working fine. Then Seeed released v2.1 and 2.2 the following year to fix a few of the problems, however there were various problems with both of those versions, but they finally got most of it right with v2.3 in early 2012.

    One of the best features of the v2.3 boards is that they used the DS3231 RTC chip, which you might recognize is the same part used in the semi-famous Chronodot. That’s one of the best options for datalogger timekeeping because it is temperature-compensated. Standard RTC chips like the DS1307 (used on the Adafruit datalogger board) and DS1337 will gain or lose time if the temperature varies much. In the case of the 1307, I’ve had outdoor loggers with the Adafruit board get up to 30 minutes behind during the winter. They also lose time in the summer if the logger heats up. So overall, the DS3231 is a big improvement over the DS1307 and 1337 chips, and I think it’s essential that you have accurate timekeeping in an outdoor logger. Unfortunately, the Stalker V3.0 is using the DS1337 chips (it’s like the 1307, it just has some alarms), so anyone using the v3.0 boards outside is going to have problems keeping the correct time on the logger.

    Another criticism of the board from multiple users, that Seeed said last year they would fix but apparently did not, is that the microSD card holder on the Stalkers is very hard to use. They occasionally break off, sometimes the cards don’t get seated properly in the socket, and if you’re using a shield, you have to remove it to access the card. Supposedly they switched to this design a few years ago because it was hard to access the cards when used in their weather-proof enclosures (the ones that the stalker shape was designed to fit inside), but now they’ve changed the shape of the Stalker so it won’t fit in those enclosures, and the card is still hard to access. And apparently no one has found a good enclosure for the new 3.0 boards.

    And then there are some other little annoyances, like their supplied libraries don’t work right, there are a few errors in the board that are complicated to work around, the documentation is spotty and sometimes incorrect. There are at least a dozen things I could think of that should have been addressed with the new version, but either weren’t addressed or were made worse. And some users are reporting that the new boards use 5 times more power in sleep mode than the previous boards, which would be a major problem for the standalone, sleeping loggers I deploy. And as I’m programming more and more options and functionality into my loggers, I’m running out of flash and RAM, so the limited capacity of the processor is another headache.

    So in general, I think the Seeeduino Stalker v3.0 changed or removed several of the features I liked about the old model, they introduced some new problems, and they failed to address a few of the outstanding user requests. There aren’t many other options out there for similar boards, but it really depends on your requirements. Do you need solar power battery charging? Do you need an Xbee socket? Do you need an SD card? How important is accurate time keeping? You can buy all these things separately, (Chronodot, SD card breakout, Xbee adapter), and connect them to something like a Sparkfun ArduinoPro (Uno’s use too much power, even when sleeping and should never be used for a logger). But if you have the time and patience to work through the kinks of the new Stalker v3.0 board, then it may turn out to be okay for you.

  • #1268

    Marko.Kohv
    Participant

    I was inspired by this site to build 27 distance sensors based on Stalker v3 kit.
    The bad things I noticed are:

    the kit contains cylindrical encolsure – no way to attach connectors etc.;

    included solar panel is much weaker than v2.3, it starts charging the lipo battery only under direct sunlight. V2.3 starts to charge much earlier.

    The temperature readings show some strange values even if you copypaste the code from the Seeeduino wiki tutorial. For example, i got readings of -127 degrees. Same code produces correct results with v2.3. Does anyone has suggestion for fix in code? The problem is probably lined to changed RTC chip.

    I need those temp readings to correct distance readings, daily fluctuations during fixed testing were within 2 cm. The correlation with temperature was linear enough and corrections therefore easy to implement if I have the temperature readings.

    In the good side it seems to consume littebit less power than v2.3.

    Attachments:
  • #1384

    Steve Roberts
    Participant

    If you are referring to internal temperature from the rtc chip, there is none on the v3; value of -127 means there is effectively no sensor.

  • #1611

    Richard
    Participant

    Hi guys. I was really impressed with your early Seeduino Stalker ultrasonic water level sensor and I have tried to build one of my own.
    I was not fast enough to get hold of your Mayfly so have used a Seeduino Stalker V3 and I have been struggling to get my code to work.
    I have used a maxbotix 7360 sensor and want to try to record the Serial output as I am trying to achieve 1 mm accuracy.
    Any chance you could share the code you used with your Stalker versions of your project?
    I’m Happy to share what I have so far but as I am not really sure whats wrong with it I don’t really know how to fix it.
    It will only print one sample to the Serial output and to the SD card then goes into a coma.
    Also do you think there will be another run of the mayfly anytime soon?
    Any help you could give would be really appreciated.

  • #1614

    Shannon Hicks
    Keymaster

    I’m not sure why your code didn’t post correctly. Maybe because you attached it as a .ino file. Try just pasting it into the “code snippet” box when you’re typing a reply. Just hit the “Add Code Snippet” button in the row of buttons right above the text box, past your code into the window that pops up and choose “Arduino” from the Language drop-down menu so it formats the code properly.

    Here’s some code that I used a long time ago when using the Maxbotix sensors with a Seeeduino Stalker. In the example, I connected the data line of the sensor to pin D7, then just connect the sensor to ground and its power to 3v3. Communicating with the Maxbotix sensor only uses pin 5, 6, and 7 on the sensor. The sensor outputs a digital string every second when it’s powered continuously. If you only want to take readings periodically, you can power the sensor momentarily with any of the free digital pins on the Stalker since the sensor only uses a few milliamps so the Arduino digital pins can source that. In the following example, it’s powered all the time.

  • #1617

    Richard
    Participant

    Hi
    Thanks for the help, I really appreciate the well commented code as I really have no idea whats going on without it.
    I tried your code and perhaps I was having data issues because Of something I did or because of a different sensor but I was getting quite a few out of sync readings that would throw a spanner in the works for using the data later.
    I have had really good data coming from the code attached here, hopefully between the two options someone may get some benefit out of these options.

  • #1619

    Richard
    Participant

    Ok so I have the sensor reading well with the code above and I have a sample of the seeduino datalogger that also seems to work but I cant seem to embed one code to the other and have it keep working. it just seems to put the poor little arduino into a coma after taking and writing one sample to the SD card.
    Ill attach the datalogger code and hopefully some clever person out there can help.
    this code works well on its own.

    • #1624

      Shannon Hicks
      Keymaster

      Did you put a solder blob across the pads of P3 on the back of the board? You’re using INT0 in the code, so you need to close the pads that connect the RTC interrupt signal to pin D2, and according to the Stalker 3.0 wiki, that is accomplished by shorting out P3. I have not used a Stalker 3.0, but I know on the Stalker 2.3, the board would go to sleep after one reading and never wake up again if I forgot to short that RTC INT0-D2 solder jumper.

  • #1626

    Richard
    Participant

    Hi
    I have just double checked the jumpers I soldered across P2 and P3 as you say to make sure it was not some sort of dry joint problem and all seems well.
    The problem I am having it seems is that the software serial is not playing ball after the first sleep, wake up cycle. I have just tried the re allocating sonar onto pin 8 instead of pin 11 and got totally different behavior so will try some more things and give an update. All of the info I can find pointed to pin 11 being free as was pin 8 so I wonder if I am Missing something.

  • #1627

    Shannon Hicks
    Keymaster

    Pins 10, 11, 12, and 13 on the Stalker are used by the SPIbus, so if you’re want to use the microSD card socket, you can’t use those digital pins for anything else. It’s been awhile since I looked at the specs of the Stalker, but I think there are very few free pins. That’s one of the reasons we stopped using it and created the Mayfly. And the Mayfly’s secondary hardware serial port makes it easier since you can sometime avoid using the SoftwareSerial functions if you just have one serial device to interface with.

    The Mayfly boards should be available again on Amazon by this weekend.

  • #1628

    Richard
    Participant

    Awesome, I will be one of the first to buy one once they are back in stock.
    The 10 11 pin issue is what seems to have made things screwy all along, Now to go find some free pins, using pin 8 seems to make it cycle through the sleep awake about 4 times before getting another sample. It may still be broken but at least it’s different broken 😉

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