No Propeller Chip found. Is my chip dead?
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Hi folks,
I'm trying to get an LED to blink on my breadboard propeller setup. When I try to download the Spin file or click the "identify Hardware" button, I get the following message: "No propeller chip found on any serial port. Scanned COM7". My PropPlug briefly flashes blue when I click that button, or when I type text into the Parallax Serial Terminal, which suggests to me that my PC is indeed sending the right signals down my USB cable. My suspicion is that my propeller is failing to respond. Here are the possibilities as I see them, based off what I've read about similar problems in these forums:
1. My chip is dead.
2. The chip is fine, but I messed up my Tx/Rx connections.
3. The chip is fine, but it's not getting power.
4. The problem lies with the software (drivers, etc).
As I said, option 4 seems unlikely. I've quintuple checked the Tx/Rx connections, and they seem fine. I checked with a multimeter that the chip is getting 3.3V. Soooo, it looks like option 1 might be it. Which would suck. Before I buy a new chip, I'd like to be sure that this chip is actually dead. Is there any simple way to test that? Also, does anyone have any other troubleshooting suggestions? Thanks in advance for any responses!
I'm trying to get an LED to blink on my breadboard propeller setup. When I try to download the Spin file or click the "identify Hardware" button, I get the following message: "No propeller chip found on any serial port. Scanned COM7". My PropPlug briefly flashes blue when I click that button, or when I type text into the Parallax Serial Terminal, which suggests to me that my PC is indeed sending the right signals down my USB cable. My suspicion is that my propeller is failing to respond. Here are the possibilities as I see them, based off what I've read about similar problems in these forums:
1. My chip is dead.
2. The chip is fine, but I messed up my Tx/Rx connections.
3. The chip is fine, but it's not getting power.
4. The problem lies with the software (drivers, etc).
As I said, option 4 seems unlikely. I've quintuple checked the Tx/Rx connections, and they seem fine. I checked with a multimeter that the chip is getting 3.3V. Soooo, it looks like option 1 might be it. Which would suck. Before I buy a new chip, I'd like to be sure that this chip is actually dead. Is there any simple way to test that? Also, does anyone have any other troubleshooting suggestions? Thanks in advance for any responses!
Comments
Do both Rx and Tx LEDs blink at some point when trying "Identify Hardware" ?
There are lots of posts on this subject and I have recently learned a couple of new tricks to address it - down to Windows rather than the Prop. The experts will be along in a short while...
I have given many Prop chips lots of (quite extreme) abuse and they have survived.
Hugh
This is just about the most common problem that new users run into. So you will find a lot of discussion about it. But it generally is just part of the learning curve to sort out three things: [a] software installed on the computer correctly; the Propeller is wired to the serial port correctly, [c] you are providing power to the Propeller.
Even when I switch from Propeller Tool to other software, the process starts all over. I have had to sort out Brad's Spin Tool, Catalina C, and SimpleIDE.
So you might help us help you by providing a few details about the context.
Jazzed: No, I don't think that both Tx and Rx were blinking. One is red and one is blue, right? My recollections is that when I first plug in the PropPlug into the USB port, both lights blink, but when I click the "Identify Hardware" button, only the blue light blinks.
Hugh: I'm curious, what sort of abuse can the chips survive? I was extremely careful with the power supply. I'm using a 9V battery, and then a LM317 voltage regulator circuit on my breadboard to bring down the voltage to around 3.3V. I repeatedly checked with my multimeter, and the voltage was around 3.5V every time, which is close enough (according to the datasheet, the propeller will take 2.7-3.6V). My worst fear is that, in principle, I could have switched + and -. But I put a simple LED circuit in parallel with the chip, just to make sure that A. I wasn't putting in too much voltage and B. I had correctly identified + and -, and yes, it all looks correct. Has anyone ever accidentally reversed the polarity or given too much voltage? Did the chip survive? Also, do I need to worry about how much current I'm sending through the chip? I think the datasheet said that 300mA was the preferred current, I'm not quite sure how much I gave the chip.
Loopy: Here is what I can tell you about the context: I'm running Windows 7. I reinstalled the Propeller tools and the drivers, just to make sure everything was up to date. The installation proceeded fine. I looked under Control Panel/Devices, and a COM port appears when I plug in the ProPlug and disappears when I pull it out, suggesting that the computer recognizes the device.
Most problems of this sort are due to the reasons Loopy Byteloose noted. The blinky lights sound correct. The first flashing of both is when Windows finds the USB adapter and configures it. The blue flashing later is when the Propeller Tool (or whatever) asks whether there's a Propeller there. Is the Propeller powered when that happens? What kind of Propeller board are you using? If not, how do you have the Propeller connected? Details are important.
Here is a list of common abuses that some claim not to matter, but Parallax would prefer you didn't ask for a repair or refund if you intentionally choose to pursue.
1. Over-clocking -- some people run faster crystals with the Propeller for higher performance, mostly video generation. The faster clock creates more heat and more current.
2. Using 5 volt devices directly with 3.3v without protecting the Propeller i/o. There is a huge debate about what size resistor will protect the Propeller. I opt for 3.9K ohms, which is conservative and supported by Beau Schwab. (He usually gets things right.)
3. DIY serial interfaces of various sources.
4. Not providing grounding and 3.3v to all the pins that provided on the Propeller for such (not a good idea)
5. Not providing by-pass capacitors between al 3.3v pins and ground.
6. Expecting a USB port to provide all the power to a Propeller project. In some cases, a Propeller board with run from a USB port, but the USB port was never intended to provide more than 500ma of current. In many case the USB cable won't properly deliver even 500ma. So don't expect such a support to drive much more than a few blinking LEDs.
7. Powering the Propeller with more than 3.3 volts
8. Providing a Vin voltage beyond the boards specified limits because the voltage regulator claims it will work up to 30 or so volts.
There are other abuses that are unintentional.
Reverse polarity to the power connections is the most common beginner's mistake and usually means sudden and complete death to the Propeller or to an LCD display. On the other hand, many voltage regulators actually include protection against reverse polarity.
Negative voltage to a Propeller i/o will likely damage that particular i/o chip.
Lack of by-pass capacitors or complete voltage supply wiring has been know to damage the PLL section of the Propeller, but the device will still operate in modes that don't require it.
There's a long list of trouble shooting steps to take and unfortunately having the Propeller on a breadboard makes the list even longer than when using a QuickStart or other ready made board.
I know there are a lot of fans of the breadboard version of the PEK but I personally think there are enough ways to get this wrong without adding DIY hardware to the mix.
It would probably help if you take a high resolution photo of how the chip is wired.
I agree with others that the Propeller can survive a good amount of abuse but I know I've personally killed over six chips (it's probably closer to a dozen).
HI.
The PropPlug leds should flash one after the other almost simultaneously with "Identify Hardware" as blue then red. If only the blue LED blinks with Identify Hardware, then there is a problem with the propeller or a connection from P30 or P31 to the PropPlug.