Home › Forums › Other Data Loggers › Seeeduino Stalker v3.0 discussion › Reply To: Seeeduino Stalker v3.0 discussion
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.