computer not registering $50 robot

[agold]

Hi,

I've just finished the $50 robot board and was trying to modify the servos, I downloaded the .hex file in the servo modification tutorial but when I tried to upload it (or the photovore code) to the microcontroller it came up with the 'Device missing or unknown' alert.

The device manager in the control panel (that the $50 robot tutorial says to use to check the COM port) doesn't have it in it and the screen to chose the COM port in PonyProg only has 1 COM port that you can select (my printer).

I've checked the battery, which is working and I'm fairly certain that my wiring and soldering is correct

I'm using the serial dongle port programmer without a USB to serial converter

Thanks

Adrian

[Pratheek]

Have you set the target device as Atmega8 in PonyProg?

[agold]

Yep, I've selected AVR micro and ATmega8 in PonyProg

In PonyProg when I click the spanner to select the COM port I am not able to select any as my printer was the only thing there and it's off.

[agold]

I've rechecked all the wiring and voltages at the I/O ports and it outputs the correct voltage
Could it be my ATMega8 thats stopped working?

Another quick question, the tutorial said that the microcontroller was static sensetive can it also stop working through static while in the socket in the circut board?

Thanks

Adrian

[agold]

Hi all,

I ordered another ATMega8 and it finally arrived a few days ago so I've been rechecking my board and the only unusual thing I found was a resistance of ~5.5K ohms between the ground and +5v output of the voltage regulator (it's a LM7805C 5v voltage regulator) is this normal?

So far I've checked the voltages at the sensor and servo ports and also checked the resistances between points to ensure that there are no shorts and both of those tests have been fine, what else should I test before I insert the ATMage8?

Thanks for the help

Adrian

[Soeren]

I found was a resistance of ~5.5K ohms between the ground and +5v output of the voltage regulator (it's a LM7805C 5v voltage regulator) is this normal?

The value should be changing while you measure, as there should be capacitors from +5V to ground.
Hopefully you didn't measure with the controller in the circuit.

[agold]

Soeren,

The value should be changing while you measure, as there should be capacitors from +5V to ground.

Are you sure there should be a cap between +5v and ground? on the tutorial there is only a cap (between the two battery inputs)

Hopefully you didn't measure with the controller in the circuit.

no, I didn't measure it with the chip installed I'm looking for things to test before hand as I somehow blew my other chip (I think).

With the smoke test, do I just connect a multimeter set to amps in series with the board and connect it to a variable power supply?

Thanks for the help,

Adrian

[corrado33]

Another quick question, the tutorial said that the microcontroller was static sensetive can it also stop working through static while in the socket in the circut board?

I don't think so.  Yes the MCUs are static sensitive, but if it's just sitting in it's socket, it should be fine.  I find it hard to believe you blew up your AtMega8.  I've done some pretty bad things to mine and it still works wonderfully.

And the caps that Soeren is talking about are simply to give you a nice stable power supply.  Adding caps between the battery terminals somewhat stabilizes the power from the battery, while adding caps between +5V and ground somewhat stabilize any power spikes that your circuit could draw.  Are they always required for something to work?  No.  Should you have them anyway?  Yes.  If you followed the tutorial correctly when building the $50 dollar robot, your circuit should be fine, but for other applications/robots, you should probably include more power stabilization items (like caps between +5V and GND).

I don't know if "power and stabilization" are the best words to describe what I'm talking about, but the general idea is correct. 

With the smoke test, if nothing smokes,  you should be fine.  I generally just test voltages when I test my circuits.  I check and make sure that certain voltages appear where they are supposed to, and they don't appear anywhere else. 

It almost seems like your computer isn't recognizing the programmer more than something is wrong with your MCU.  Did you try using the serial port your printer is connected to instead? 

[agold]

It almost seems like your computer isn't recognizing the programmer more than something is wrong with your MCU.  Did you try using the serial port your printer is connected to instead? 

yes that's what I thought as well but seeing as the ATMega8 is about $3 and I couldn't find anything else that was wrong with the board I decided to try with a new chip.

I have the serial dongle port programmer so I don't think the computer should be recognising that by itself should it?

The printer doesn't use a serial port (it uses USB) so no I haven't tried it with that port.
Is there a simple way to test if the serial port is working or not?

Thanks for putting up with all my questions,

Adrian

[Soeren]

Hi,

Another quick question, the tutorial said that the microcontroller was static sensetive can it also stop working through static while in the socket in the circut board?

I don't think so.  Yes the MCUs are static sensitive, but if it's just sitting in it's socket, it should be fine.  I find it hard to believe you blew up your AtMega8.  I've done some pretty bad things to mine and it still works wonderfully.

It could have been zapped before going into the PCB, or the controller might have high impedance pins unterminated.
Lots of bad stuff of the ESD variety can happen to a full board - there's a reason for expensive antistatic (clear/silver) bags and conducting (black) bags, of which only the latter type is good. With ESD, you'll never really know for sure what happened or when.
ESD can do damage akin to The Secret Kung-Fu Delayed Death Punch^(TM) that kills you after precisely one year (allways wondered why those hit didn't just nail the bastisch good within that year  ), only with a less predictable outcome, it might run perfect for several years and then die screaming, or it may run erratically but with inconsistency, making such an error nearly impossible to find - the only sensible thing to do if ESD damage is a likely offender is, to swap the parts and if that helps, hit the old parts with a very large hammer, so that you won't use it again at a later date by mistake.

And the caps that Soeren is talking about are simply to give you a nice stable power supply.  Adding caps between the battery terminals somewhat stabilizes the power from the battery, while adding caps between +5V and ground somewhat stabilize any power spikes that your circuit could draw.  Are they always required for something to work?  No.  Should you have them anyway?  Yes.  If you followed the tutorial correctly when building the $50 dollar robot, your circuit should be fine, but for other applications/robots, you should probably include more power stabilization items (like caps between +5V and GND).

If you wanna tell other people what I'm on about, at least get it correct

Caps are allways required with a voltage regulator to avoid oscillations!
Caps are allways required with a controller, as high speed digital circuits draw current in sharp pulses, so they need the caps as local buffers for the supply, both to be able to draw the current and to do so without swamping the power bus with noise.

With the smoke test, if nothing smokes,  you should be fine.

I'll have to disagree here.
The "smoke test" is an old term from back when most components actually smoked when they died from over-current, but semiconductor (eg. a transistor or a controller) will die quite smokeless most of the time. These days, the term is just a leftover and "initial run" would be a more descriptive term to use.

The smoke test is just the first run when you're absolutely (99.999%) sure there's no errors in neither the design nor the layout.
You use the term on software (and even totally smoke-unrelated stuff) as well.

It almost seems like your computer isn't recognizing the programmer more than something is wrong with your MCU.  Did you try using the serial port your printer is connected to instead? 

Yes, first step is to get the OS to recognize the port.
No program will gain access to ports that the system doesn't know of.

[agold]

Hi Soeren,

Thanks for all the information I think I understand most of it but please tell me if I'm correct.

Caps are always required with a voltage regulator to avoid oscillations!
Caps are always required with a controller, as high speed digital circuits draw current in sharp pulses, so they need the caps as local buffers for the supply, both to be able to draw the current and to do so without swamping the power bus with noise.

by oscillations do you mean variation in supply voltage?
I realised that there is another cap in the $50 board that I forgot when I posted my other question - the ceramic disc is what would have given me that 5k ohm reading isn't it?

I'll have to disagree here.
The "smoke test" is an old term from back when most components actually smoked when they died from over-current, but semiconductor (eg. a transistor or a controller) will die quite smokeless most of the time. These days, the term is just a leftover and "initial run" would be a more descriptive term to use.

The smoke test is just the first run when you're absolutely (99.999%) sure there's no errors in neither the design nor the layout.
You use the term on software (and even totally smoke-unrelated stuff) as well.

so what do you suggest I look for when doing smoke tests?
I had a go with a smoke test and the current draw stayed below 6mA and the voltage was correct at the sensor and servo ports so referring to the tutorial I assume that's fine.

It almost seems like your computer isn't recognizing the programmer more than something is wrong with your MCU.  Did you try using the serial port your printer is connected to instead? 

Yes, first step is to get the OS to recognize the port.
No program will gain access to ports that the system doesn't know of.

I'm using the serial dongle port programmer so I think that I need a board connected for the computer to notice it - is that right?

Thanks,

Adrian

[corrado33]

If you wanna tell other people what I'm on about, at least get it correct

Caps are allways required with a voltage regulator to avoid oscillations!
Caps are allways required with a controller, as high speed digital circuits draw current in sharp pulses, so they need the caps as local buffers for the supply, both to be able to draw the current and to do so without swamping the power bus with noise.

Man I really need to read up on my electronics    Honestly though, that's what I meant... I promise...

Oh and about smoking... I know that a lot of parts die without smoking anymore, but don't you usually smell it?  Every time I've ruined something electronic it's smelled a very distinct smell.

[agold]

Hi,

Sorry I've been busy and haven't had time to post again before now
So does it seem like I'm all set to insert the Mega8?
apologies for repeating this question but it seems to have been forgotten amidst all my other questions-is there a simple way to test the serial port without a device that uses a serial port?

Thanks,

Adrian

[agold]

Hi,

I found this way to test a serial port only it has different pins to connect depending on the type of port (RS-232, RS-485, RS-422) how do I know what type I have? I checked the users manual and couldn't find it there

Thanks,

Adrian

[Soeren]

232

[dunk]

hey Adrian,
so just to confirm,
your operating system is only seeing 1 serial port and that's the one for your printer right?
the printer plugged into an actual serial port or is is a USB one emulating a serial port?

it sounds to me like you are missing a serial port.

you are talking about COM ports so i presume you are using windows.
what COM ports show up in device manager?
if again it's only your printer, try checking you have your serial port hardware enabled in BIOS.



to test a serial port, open your default terminal software (Hyperterminal in windows) and connect to that COM port. skip past any settings about phone numbers, etc.

now connect pins 2 and 3 on your COM port.
this creates a loopback. any data that is transmitted out pin 3 gets sent straight back into pin 2.
the effect of this is you should see anything you type in Hyperterminal appear back on the screen.


dunk.

[agold]

your operating system is only seeing 1 serial port and that's the one for your printer right?
the printer plugged into an actual serial port or is is a USB one emulating a serial port?

My printer is plugged into a usb port but that port came up as COM3 in PonyProg

what COM ports show up in device manager?
if again it's only your printer, try checking you have your serial port hardware enabled in BIOS.

As far as I can tell no COM ports are in device manager

I tried a loopback test but when I went to select the communication type I wasn't able to select a com port the only option was 'TCP/IP (winsock)' and I couldn't select the COM port, Any ideas what might be happening?

[dunk]

i'm fairly sure windows does not know about your COM port.
it's been years since i used windows but i think you should have the full list of available COM ports where you are only seeing 'TCP/IP (winsock)'.

the COM port should be in device manager somewhere if it exists. even if it has errors you should see a malfunctioning device.
i'm afraid i can't be much more help as my windows knowledge is very limited. maybe someone else on here can help.


one thing you should try is make sure the serial port is enabled in BIOS.
another possibility is that you only have a DB9 plug on the back of your PC case and it is not connected to anything inside the case. (i've seen stranger things...)


dunk.

[agold]

Dunk,

one thing you should try is make sure the serial port is enabled in BIOS.

I have absolutely no idea how to do that do I open a program and change which ports can be used?

Thanks,

Adrian

[dunk]

no.
when you first boot your computer, before windows loads, it should be possible to enter a menu to change some very low level hardware settings on your computer.
the exact process varies depending on you PCs motherboard make, model, etc.

a common setup is you will see "Press ESC to enter Setup" or something like that shortly after you switch on *before* your computer starts loading windows off the hard drive.

providing you work out how to enter the BIOS setup utility there will be an option somewhere that mentions Serial ports.
make sure yours is switched on and then save and exit. (be careful not to change any settings you don't know what are...)


can i just confirm something,
you are trying to use a serial port on your PC right?
on all home PCs less than 10 years old this will be a male 9 pin "D" shaped connector called a DB9.
like this: http://images.google.ie/images?q=db9+connector


good luck,

dunk.

[agold]

Hey Dunk,

Thanks for your help, the startup screen flashes so quickly that I haven't found out how to enter setup yet.

can i just confirm something,
you are trying to use a serial port on your PC right?
on all home PCs less than 10 years old this will be a male 9 pin "D" shaped connector called a DB9.
like this: http://images.google.ie/images?q=db9+connector

yes that's the one I've got.

for the last few days I've been setting up a computer to use specifically for robotics (that's why I haven't replied till now) and it has two serial ports on it and the loopback test worked fine on them and I was able to connect the board (with the ATmega I thought I'd blown I might add ) to it so I'm now modifying the servos which is coming along fine.

Even though it's no longer so important I'd like to get my other serial port working, any other ideas to find how to get to Bios?

Thanks

Adrian

[Soeren]

Hi,

[...] any other ideas to find how to get to Bios?

Usually, you use either DEL or a function key, F12, F10 and F5 seems to be the most used, but try them all until you get lucky.
At start up, just pump the selected key rapidly until you either get into BIOS or get past the point, at which point the on/off/restart button will give you a new try faster that booting it entirely.

You could try to find it on the web, by Googling "enter bios xxxx", where xxxx is the name and model of your PC or your motherboard - If you still have the mobo manual, that would be the place to find it.

[agold]

You could try to find it on the web, by Googling "enter bios xxxx", where xxxx is the name and model of your PC or your motherboard - If you still have the mobo manual, that would be the place to find it.

I didn't think of that because I didn't realise that it was actually the motherboard but that makes sense I suppose.

I'm going to research a bit more before I actually try it but I now know how to get there.

I asked the IT expert at my school and he said that normally serial ports can't be disabled and that most likely something had blown - does that make sense?

Thanks,

Adrian

[dunk]

I asked the IT expert at my school and he said that normally serial ports can't be disabled and that most likely something had blown - does that make sense?

not true. it is possible to disable serial ports on some (but not all, maybe 75%) of motherboards.
i'm not saying that this is definitely your problem is but it is one of the things i would check on a computer with the symptoms yours has.


dunk.

[agold]

Hi all,

Thanks for the help, I finally got around to going into BIOS and checking it out, it took about five minutes

I set it to 'auto' as there was no 'enabled' setting and it works fine.

Thanks again,

Adrian