[FTC]: Samantha? Like it or hate it?

[emmell]

I'm sorry to hear about the problems in New York and St. Louis. I was the FTA for the Kell Robotics FTC Qualifier in Georgia and we saw none of those problems. This was the first qualifier for our state and so we had to flash each of the Samanthas with the configuration for the FTC_FIELD and FTC_PIT routers. Out of the 11 teams, we only had 2 problems with Samanthas in getting the flash to work properly (the FTC_FIELD worked, FTC_PIT didn't). So those two teams had to be tethered in the pits to practice. But no one had any problems communicating with the FTC_FIELD router.

We did have 2 issues during our qualification matches. One team got hit hard and Samantha dropped communications. The other, the NXT locked up and wouldn't respond to anything (we saw that happen with Bluetooth as well). Samantha stayed connected to the FCS during the lockup, so I don't know what happened there.

One thing that was great was that we didn't have any problems getting the teams back up and running for matches 2 through the end when they reported back to the field. The teams put the robots on the field and turned them on and the FCS found them right away and we were ready to start the next match. As a tournament organizer, I find that to be the best leap in progress with working with these robots with a centralized FCS. So, don't be too hard on Samantha yet.

So, a couple of tips that the teams and organizers should know:
1) Teams: Do not bring your routers to the competition. Keep the wifi to a minimum to keep it open for the competition.
2) Organizers: Make sure you set up the FTC_FIELD on one channel of the WiFi spectrum and FTC_PIT on a different one. Having them on the same channel will just confuse things.
3) Teams: Make sure your Samantha is not buried in the bowels of your robot. It's best to mount it vertically and with the red button on the top (the actual antenna is on top of the unit).
4) Teams: Get a small 1 foot USB extension cord and plug that into the Samantha unit and zip tie that securely to Samantha and the bot. You can then plug your USB cable from the NXT into the extension cord. Then, when the organizers need to flash Samantha, you can just disconnect the USB cable from the extension cord and plug the flash drive into it. Then flash Samantha and reconnect the cable. This will also relieve any stress that directly affects the Samantha unit. Also, get a small USB A-B cord (1'-1.5' feet). Secure these cables to the robot with zip ties.
5) Teams and Organizers: If you do have two routers (FTC_FIELD and FTC_PIT), make sure you wait 30-40 seconds during the flashing process to get both network's information loaded onto the Samantha. The Red, White, Blue lights should light up in succession twice (once for the FTC_FIELD and the second time for FTC_PIT). Then connect to the FTC_PIT router while in the pits to test out the bot. When you come to the field for the first time, you may have to press the red button on Samantha to sync. Then you'll be set for the day.
6) Teams: Make sure you compile and download the Samostat program to your brick. You can find it two folders under the Program Files\Samantha Field Control System folder. One for LABView and the other for ROBOTC. Pick the appropriate one for your system and install it on the brick. FTAs will use that program to see your configuration status for Samantha and make sure you can talk to the field and pit routers respectively.

I hope this will help you. Good luck to all the teams and all event organizers out there.

[jamie_1930]

I just realized something about what may have happened at Clarkson. When you went through the final phase of inspection and did the testing match, the FTA working the pit loaded the samantha wifi configuration. This configuration must have been the FTC_FIELD configuration, because it's the same configuration we used on the field. emmel said that at georgia the had a FTC_FIELD router and FTC_PIT router, meaning that if you were testing in the pit you would have to load the pit configuration and if you went onto the field you would load the field configuration. Now at Clarkson we had an area to test your robot with samantha in the pit, but never had to change configuration if we were on the field and then went to the pit and vice versa. Meaning that we had two seperate routers running the same configuration, while the matches were carefully looked over it was almost like it was free rein in the pit. If you wanted to run a test match you just need a field tech to come over and start the match. I feel like every time I came out of a match I saw people on that pit field. So what I'm trying to say is that at Clarkson we had two routers running the same configuration, and sometimes running matches at the same time, this seems exactly the kind of situation that could lead to the problems we saw.

[ssi]

Actually, the Samantha holds TWO configurations at one time. It can know how to connect both to an FTC_FIELD and an FTC_PIT at the same time. That is why they did not have to load a separate configuration for each area.

[emmell]

Originally Posted by ssi

Actually, the Samantha holds TWO configurations at one time. It can know how to connect both to an FTC_FIELD and an FTC_PIT at the same time. That is why they did not have to load a separate configuration for each area.

Exactly right. David beat me to replying.

[wilsonmw04]

Just coming back form the Richmond Regional, I have to say that Samantha worked much better than the Bluetooth solution from last year. Matches all ran smoothly throughout the day. There were 4 communication issues my team encountered today. Twice, our NXT froze in the middle of matches after sustaining a shock during normal game play. Samantha stayed connected on both occasions. Second, one of our alliance partners lost communications with the field. The cause of the disconnection was a poor power connection. The last was a miscommunication with the field staff about which controller set my team was using during an elimination round. None of these were do to the Samantha module.

[Andrew Schuetze]

the later posts in this thread seem to validate that the Samantha unit is working but we do need to learn what causes large scale crashes to improve on the best practices for tournament organizers and team behaviors. I think the post by emmell is a must read at this point for everyone either competing in or running FTC events.

[JesseK]

I don't think the posts in this thread are indicative of a 'lack' of problems that were experienced.

1.) The FTC organizers need to send out something official to all of the teams in TIMS about best practices in mounting the modules. Go to an FTC event and ask around about ChiefDelphi ... very few (rarely ever a first-year team) have heard of the website.
2.) Telling students their battery voltage dipped during the match (which is why the module dropped out), yet not allowing the students to see how bad the drop was (length of time, amount) in order to determine whether or not to return a brand new 13.7V battery back to the mfr. is not the way an FTA MVP should treat people he wants to sustain within his program long term
3.) If we're expected to have proper battery voltage meters, SEND IT OUT IN AN OFFICIAL UPDATE. As 'smart' as the mentors are, we are incredibly dumb about the many things we can't even fathom postulating, let alone knowing we need the something. (The flip side it true as well)
4.) Fact: if we ever change communications modules again in FTC, we will forgo the FTC program. Sure the 4 teams we have are nobodys, but we've gone through this exact experience twice now. A robot sitting still on the field doing nothing is not a way to 'Celebrate' the accomplishments of the students. We are tired of being an 'experiment' for the lowest bidder. It is very obvious the Samantha modules were not shock tested one bit. Even with a proper USB attachment to the frame, I could thump the thing and reset it.

[emmell]

I just want to make some suggestions about the previous post:

Originally Posted by JesseK

1.) The FTC organizers need to send out something official to all of the teams in TIMS about best practices in mounting the modules. Go to an FTC event and ask around about ChiefDelphi ... very few (rarely ever a first-year team) have heard of the website.

I beg to differ. FTC has sent out something official. Read all of the Team Email blasts that have been sent. The blast on 11/18 had a link for a white paper with a diagram of how best to mount the Samantha module. You can find the email blasts here: http://www.usfirst.org/roboticsprogr....aspx?id=18132

Originally Posted by JesseK

2.) Telling students their battery voltage dipped during the match (which is why the module dropped out), yet not allowing the students to see how bad the drop was (length of time, amount) in order to determine whether or not to return a brand new 13.7V battery back to the mfr. is not the way an FTA MVP should treat people he wants to sustain within his program long term
3.) If we're expected to have proper battery voltage meters, SEND IT OUT IN AN OFFICIAL UPDATE. As 'smart' as the mentors are, we are incredibly dumb about the many things we can't even fathom postulating, let alone knowing we need the something. (The flip side it true as well)

I won't comment on what the FTA told you at your event, however you don't need a voltage meter at a competition. Your NXT will tell you what your battery levels are and so will the FCS if you are running it with the FTC_PIT configuration. If your NXT is >7.5 volts, then you're good. Anything less than 7.0 volts will probably not work well. For your TETRIX battery, anything greater than 11.0 volts is good and < 9.0 volts will not run. The FCS will light with Red, Yellow, and Green in the team box for these conditions. This is documented in the FCS manual.

I won't comment on the 4th item. Just pointing out the facts. The key for all the mentors and teams out there - READ EVERYTHING THAT YOU GET. It's important information and will help you be better prepared for your next event.

Good luck teams!

[PSHRobotics]

The biggest problem I personally found in how the regional in St. Louis occurred was the determination if a match should replayed. This is nothing against the referees as they were forced to make decisions on the spot in order to make sure the competition continued to run smoothly. This, I feel, is more a problem of the rules.
The referees decided to only replay one match throughout the day. The reasoning for replaying this match was because the referees felt that there had been a "significant" impact to the outcome of the round. The rules need to be rewritten to account for factors such as this to avoid confusion and make it easier for the referees. There were many tempers that were ignited because of this specific round being replayed, while others had not been replayed - a rule would redirect anger away from referees who already have other frustrations pointed in their direction.

[l0jec]

Originally Posted by PSHRobotics

The reasoning for replaying this match was because the referees felt that there had been a "significant" impact to the outcome of the round.

I beleive the reasoning was because that signifigant impact to the match was determined by the FTA to be a direct result of the field. The other matches which were not replayed were not determined to be caused by a field fault.
Of course we can argue all day whether certain communication issues where because of the field control system or because of individual issues such as loose wiring on samathas, but and the end of the day, I think the refs and FTAs already make their decisions as best they can based on what they have available to them in a fair manner.
Perhaps there simply needs to be better communication to teams when such decisions are made?

[EthanMiller]

New information from an informant at Clarkson shows that some of the problems may have resulted from poor setup on Clarkson's part - I don't know the details of it, but it sounds like not quite everything was set up right and/or tested realistically.

[Random Dude]

In terms of router naming, one issue I ran into when running a scrimmage out in Oregon, was the school I was at already had a router named "FTC_FIELD", which I didn't know at the time. I think it got turned on part way through the morning, and I suddenly had 1/2 my teams complaining they couldn't connect.
Once I tracked that down, I decided to put custom names on all my competition routers. That way if someone accidentally turns on a FTC_FIELD router at a competition, my network won't collapse. I also plan on running around with a WiFi scanner and disabling any rogue access points.

[Shadowfl]

I honestly can't say much about this question because it is my rookie year in FTC. but from what i know from technological evolution i conclude that the Samantha system does its job pretty well for its first year of mainstream FTC competitions.

[aklego]

I just FTA'ed at a small regional and we had two of the problems mentioned here: Signal drops and NXT lock ups.

Excepting the occasional loose wire, the signal drops were caused by low 12v batteries. However, I'm reluctant to blame that on the teams. The FCS uses essentially open circuit voltage to determine the state of charge. That is problematic, as a moderately discharged battery can still show green. Then, as soon as a load is applied, the voltage drops below the Samantha minimum and the module resets. We were fortunate in that our tournament had a 3-hr built in break. During this time, all the teams fully charged their batteries and the problem vanished. Teams that did all their practice and testing using tethering or bluetooth would never see this issue until their tournament. And teams that use many heavily loaded dc motors will be much more vulnerable to dropouts.

An inelegant fix for next season is to run samantha off of an independent battery.

NXT lock ups were the other issue. The only pattern I saw was that some robots never had the problem; the robots that did, however, had it repeatedly (but not consistently).