I just want to share some of our experiences during the past few years with all the rookie teams. [Robot Acting Differently] Please be aware that the NXT motors are running on battery pack! Just like any computer, the NXT software and CPU on the brick should run consistently every time. Since this is Robotics, beside the computer chip and software, there are also moving parts (motors), sensors (that need adjustment), and hundreds of LEGO pieces (that might come loose). We have a student screaming this Monday "Did someone make any change to the Robot; it was running perfectly when I left on Saturday!" What has happen was that he wrote the program with a half charge battery on Saturday afternoon, and we have fully recharged the battery before they met again on Monday! The fully charged battery will allow the motor to run a bit stronger and will throw off a (precision) program that worked perfectly the day before. Just like any other battery operate power equipment, a fully charge power drill will run differently versus one running on a low charge battery pack! Don't be surprise when the kids have finish all their missions perfectly the Friday night before just to find out nothing run right the next Saturday at the competition! We blame it on the table, lighting and mission models at the competition. But, it can also be that fully charge battery on competition day! It is really tough for a rookie team to deal with all the challenges, we been there and know exactly what you are going thru. As coaches, parents, teachers, we need to stay calm and not stress out as competition day is quickly approaching since the kids are just watching us to see if we will give up and throw in the towel or not! [Block Skipping] Please be aware that the 'Motor' block has a 'Wait for Completion' checkbox, while the 'Move' block has a 'Next Action' selection of 'Brake' or 'Coast' (on v2.0 only). These selections have significant affect on a program. As an example, if you have the 'Motor' block to move an attachment (or a wheel) for 1 rotation, but something is blocking it and the motor cannot turn a full 1 rotation, with the 'Wait for Completion' check, the program will hung since it is still waiting for the motor to complete the 1 rotation before move on to the next block. However, if you don't check the 'Wait for Completion' and the 'Power' setting for the 'Motor' block is not strong enough to lift three loops, the program will just continue with the next program block and continue running like the 'Motor' block never even get executed. [Debugging Program] The best way to debug a program is to use a 'Wait' block (the hour glass icon). Just change the default 'Touch Sensor' to the 'NXT Buttons' by select it from the drop down list box. Now you can make as many copy of this wait block as needed and place them anywhere after any block of code. The robot will stop and wait until you press the 'Enter' button before it continues on to the next block. You can delete these 'Wait' blocks after you are done debugging and the program is ready to go as expected. [Software Versions] Please be aware that there are different version of LEGO Mindstorms NXT Software (v1.0, v1.1, and v2.0), and there are many different version of Firmware (v1.0, v1.05, v1.07, v1.21, v1.26, v1.28) out there. You will need to make sure you have the right version of NXT Software matching up with the right Firmware version. We have discovered it the hard way when our students program on different PCs which have different Mindstorms NXT Software and the brick (having different Firmware). In one case, we have download Firmware v1.28 from a PC with NXT Software v2.0 to a brick, and then download program written on an older NXT Software v1.1 to the same brick. The robot starts acting very strange, and it did even lockup sometime. The following are the best match up that we have found (any additional comments on this are welcome): Mindstorms NXT v2.0 - Firmware v1.28 (best). Mindstorms NXT v1.1 - Firmware v1.05 (okay). Mindstorms NXT v1.0 - Firmware v1.0 (very old). To check the version of the NXT Software, run the NXT programming software, click on HELP and select "About LEGO MINDSTORMS Edu NXT..". It should say "LEGO MINDSTORMS NXT v2.0" or "v2.1" under the robot picture on the right side. There are two way to check the Firmware version. On the brick, when first turn on, press on the right arrow about 4 or 5 times and select 'Settings'. Press the right arrow 2 times and select 'NXT Version'. The first entry in the display 'FW' will tell you the firmware version on the brick. The other way is to connect the brick to the PC running Mindstorms NXT software, then open any program and click on the 'NXT window' icon (it's the one on top of the 'Download' icon). If the brick is connected, the Firmware version is display at the bottom right on top of the 'Close' button. (This is also where you can manage the memory on the brick and delete any unused programs by clicking on the 'Memory' tab.) (For Mac user check out this blog for installing NXT v1.1. and NXT v2.0: http://foresthillslego.blogspot.com/2009/10/mindstorm-nxt-20-installation-on -mac.html) [Dead Battery] If you insert a fully charge battery, but the brick will not turn on. Remove the battery and check the spring where it's making contact to the positive and negative posts of the battery. Sometime they are bent, and will not make full contact. Just adjust it a little and this might fix the problem. We also have a dead battery where it displays fully charge but just not working at all. You can only test this by putting the re-chargeable battery in another NXT brick. This is where 6 'AA' batteries come into play, but be aware that the weight of the batteries can throw off a programs on the robot that been programmed with the re-chargeable battery. [Dead Brick] We have encountered a few problems with dead brick. When download the firmware, make sure the PC and the NXT brick's batteries are fully charge. If the firmware download failed during update for some reason, the brick is dead and will not turn on. To fix this the brick will need to be reset (by pushing the hardware reset button with a paper clip) and download the firmware again. If your NXT is clicking when you insert batteries, push the hardware reset button for five seconds before you insert the USB cable. This will ensure that the brick initializes correctly for the firmware download. [The hardware reset button is located within the LEGO TECHNIC hole below the USB connector on the NXT brick.] Best wishes, T. (Curt) Tran 2007, Coach Team #3563, Rabid Llama Lords. 2008, Coach Team #324, Scitobor. -----Original Message----- From: First Lego League in Virginia and DC [mailto:[log in to unmask]] On Behalf Of Phil Smith III Sent: Tuesday, November 03, 2009 3:16 PM To: [log in to unmask] Subject: Re: [VADCFLL-L] more problems I'm sorry you're so frustrated. I can certainly believe it, especially this close to Regionals! At the risk of being called a Pollyanna (or worse), let me suggest that you make this into a learning exercise for the team: - What could (not *should*) they have done to avoid/plan for this? ("Have a spare brick" being the obvious, if not necessarily practical, answer) - What can they do *now* to get around it? (Do any of them own a brick? Can you buy one and then return it once this one is fixed? Have you called LEGO for support?) - Could it be a battery issue? Have you recharged it since the problem? - Can you try it on a PC instead of a Mac? FLL is all about solving problems. This is beyond the level of problem they SHOULD have to deal with, of course, but that doesn't mean they can't be encouraged to step up and try to figure it out. And I hope you'll come to competition anyway -- the table runs are 1/4 of the points, and the whole point is the experience, not "winning". In fact, they might find another team with an idea, or a spare brick to lend... -- Phil Smith III Virginia State Judge Advisor, 2007, 2008, 2009 Judge Advisor, Northern Virginia Regional tournaments, 2007, 2008, 2009 Division 1 Judge Advisor, Virginia State tournament, 2006 Coach, The Capital Girls, Oak Hill (retired) Team 1900 (2002) Team 2497 (2003) Team 2355 (2004) Team 1945 (2005) -----Original Message----- From: First Lego League in Virginia and DC [mailto:[log in to unmask]] On Behalf Of Sherene Silverberg Sent: Tuesday, November 03, 2009 2:38 PM To: [log in to unmask] Subject: [VADCFLL-L] more problems Lee Hilt kindly sent me a picture that showed us how to find the reset button. My son depressed the button (I was unable to see it with my old eyes) and now the brick refuses to switch on or to stop clicking so we can't reload the drivers. I have to say that I went into this FLL League with great excitement. I am now totally turned off by the entire experience. Buggy equipment, buggy programs, drivers download pages hidden so well that unless you are given the exact page, even Google's spiders struggle to find it. I have received 6 emails in the half an hour since I sent my original email. All these people are experiencing the self same problems as we are experiencing with the programs that run, not resembling the programs that were downloaded. This is the most appalling situation I have ever experienced. Lego needs to get their act together and sell equipment that works. Driver and firmware updates should be easily found. This is an exceedingly expensive exercise and for this money, I expect far better service and equipment. My team has spent more work trying to fix Lego issues than they have on developing their programs. It is most frustrating for my team to write a program, have it run perfectly 3 times and then on the 4th time have to execute a program that does not resemble the one that ran perfectly 3 times prior. Now we have a dead brick just because we attempted to reset it. Just in case you haven't realized it yet, I am fuming. Sherene -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.