I recently finished teaching a class with 15 students (16 lab stations, including mine). At one of the lab stations, when we tried to download the master code, it gave an error message something like, “Please check to see if power is turned on and serial cable is connected.” We tried changing to freshly charged batteries, but nothing would make it work.
We were able to plug the programming cable (same battery, same microcontroller, same cable) into the neighbor’s station and download a short program, but the master code could not be downloaded.
I took that same microcontroller, cable and battery home and had no trouble downloading the master code from my home computer.
Throughout the week, station after station “died”, giving the same error message. We tried using fresh batteries, but once a station died, nothing could revive it. We tried shutting off the power to every other station (each pair of computers shares a power strip) to no avail.
None of the microcontrollers, even on low battery, gave this error message from my home. Because of the finicky nature of the glitch, I suspect that it has something to do with fluctuating power.
maybe a problem with the computer not the microcontroller, did serial ports (would be highly irregular but maybe)?
noise coming from somewhere? (i know that is more so something for radio problems but if there is some kinda of disruption around serial ports it would be nigh impossible but still possible)
computer virus? (at the moment my top guess:rolleyes: because im assuming your computer is not on the station’s networks)
im just throwing stuff out here, this is very weird.
We are running student computers at a college, probably not logged in as an administrator, as the student computers are blocked access from many places (including the control panel)
The serial ports worked one day, then the next day, they wouldn’t download
programs.
I don’t know anything about noise. I don’t think it’s a virus, because the computers go into “cold freeze” and reset every time you restart. We tried turning the computers off and on, but that didn’t help either.
All the same batteries: Vex rechargeables from the Vex power pack.
Wish I could get this figured out. At least next week, I’ll only have 6 students, so we’ll have extra if half of them go bad.
What OS and SP Level are you Lab Stations running?? Do you have any other Serial Devices to check interoperability with? Are these Built In Serial Ports or are they USB to Serial devices??
Make sure that EasyC is using the right port. To check this go into the device manager and look at the USB ports, I don’t remember exactly what the category is called. Then go into easyC open up the terminal and click on the Port drop down menu and make sure the right port is selected. You can also just go through and try selecting ports on that drop down menu until you find one that works, however sometimes it allows you to select that port even if that is not where the cable is plugged in.
If this solves your problem to keep this from happening in the future you need to make sure that you always plug the cable into the same port on the computer.
No it is not. I Login normally as a Power User, the Device Manager Button (option) reminds you that you can not change anything, but you can view the current settings.
Maybe, but moving to a different computer works for a while?
I still want to know if the Serial Ports are Built In, or USB to Serial. I know of an Issue with USB to Serial devices.
I will check these out on Monday at our next class. We use USB ports on the front of the machine. It will be tricky checking the USB ports – I tried downloading photos from a camera via the USB port, and was told that I didn’t have authorization to do that on the college’s computer. Somehow, the system administrator managed to unlock the ports for the purpose of using EasyC for Vex.
I don’t think it’s a problem with the wrong port – when we first attempt to download, whether it be Master code v.7, Default code, or a program, the message “COM port open” flashes in the lower lefthand corner for a few seconds. Then the colored bar appears, as if it’s attempting to get started downloading followed by, “Please be sure the serial cable is connected and power is turned on.” What’s more, when I try to change to a different COM port via the Terminal Window, it gives me an error message much earlier on.
I checked out every one of these stations about a month ago, and I know that I had downloaded a program from the most problematic station. The thing that puzzles me most is that some stations download a simple (3-line) program, but not Master code, Default code, or the Online Window.
One thing I’m planning to try is a set of 6 fresh AA batteries from the blue battery holder. Since they’re 1.5 v each (instead of 1.2 v for the battery pack) it should be clear whether there’s a power problem.
This problem drove me crazy during this past season, and I was not able to find a single cause for the problem. I actually ran into two different issues and I am sure there may be others out there that will affect download reliability.
The first issue was configuring and utilizing the correct USB port. On my notebook I have 4 USB ports so it was a combination of the correct configuration of the port and consistently utilizing the same port everytime.
The other issue which ended up being the primary one, was the power settings for my notebook. While on battery power my notebook switches to low power consumption mode. When this happens I frequently run into the problem of slow program downloads and/or failure to download the master code. It wasn’t until the battery was running low one day, that I plugged it into an AC outlet and the connection and download started working perfectly.
Well, all’s well that ends well. We shut down the power to all stations (had to hard shut off a few), waited 5 minutes before turning back on, and still the same problem – only 3 of 16 stations were capable of downloading anything, and none was capable of downloading the master code. So we shut down all the stations except the functional ones overnight. Next morning, the 3 functional stations were dead, but all the stations that had rested overnight were working! It’s not an issue of restarting the software, because all the computers had been completely powered down for 5 minutes – allowing the computer to completely cool off seems to be the most important factor, which is why the first day, I had 15 out of 16 working stations. Allowing the computers to remain on but sleep overnight also didn’t help – it was making that cold (literally) start that made the difference.
That also explains why the stations all worked when I checked them a month ago – school was out of session and every computer had to be turned on.
I still don’t understand WHY this would make a difference.
Are the USB to Serial device plugged in during all that time, or are you walking up to the warm computer and plugging in the USB to Serial adapter and trying to download the Vex Code?
There might be an issue with the Orange VEX USB to Serial adapters (you are using the Vex Adapters, right??) being plugged in for long periods of time, but I have not experienced that.
iv had the same exact problems at my house im running a dell laptop with windows 7 and it comes up with the same problem i went through all the help forms and the manual but nothin fixed the problem my laptop is 2 years old. now my robot only has part of the program and is going insane along with that it wont lisen to the remote the only segesstion i have is convert the program files to xp manualy if using vista or win 7. the problem cant be with heat my laptop is cool all the time because i shut it off all the time and when i tryed to load the code the computer had just been turnd on from not in use for 3 days
