propeller not found :[
ohVaNiLLaGoRiLLa
Posts: 33
I have recently gotten a propeller quickstart but when i try to program it the propeller tool does not see it. It says that "no propeller chip found on any serial port" I have tried all the usb ports on my computer and even a different usb cable. When I plug it in the computer recognizes it and makes the usual sound when you plug in a usb device. The green light on the quick start is on also. When I go to edit the ports in the propeller tool and plug it in com 15 pops up and is ready to be used, it is black and not gray. So it seems to see something is there but just wont recognize it.
what do you think the problem is?:[
what do you think the problem is?:[
Comments
Have you got this figured out?
One problem I've had a couple of times is I've left the terminal window open and it automatically engages with the com port as soon as the QS is plugged in. I need to remember to click the "Disable" before the Prop Tool will see the QS. Although I think this isn't normally the case. I've deselected the "Automatically disable . . ." option.
Another thing to try is to use the QS on a different computer (if one is available).
Let us know if you still need help.
When the board is powered by USB cable only, the pin "VIN" only gets up to 3V, and "3.3V" pin only goes to 2V. Interestingly RESn pin goes high. (brown-out protection?) So the propeller wasn't able to respond to IDE at all.
So I traced the schematic, it seems that the diode "D12" drops "5V_USB" to 3V. So I replaced the diode and now it is working fine.
(When I removed the broken D12, I verified that there is only 40mA current going through this branch. So probably nothing wrong with the rest of the board.)
In that case you probably shorted the 5V USB after the diode at some point and normally the diodes can either go dead short or fail in some other manner such as you have observed.
BTW, the RESn should be high normally but I think you may have meant low since you mentioned brown-out which would be correct.
Another thing is that not all USB cables are "charger" cables, they might be fine for unpowered data connections but fail miserably when it comes to supplying power as the power "wires" might not be anything more than a flimsy copper foil thread much like cheap earphone cables (shock horror surprise when I pulled one apart). I have a test setup where I load up the device end with 25 ohms (200ma @5V) and measure the voltage drop. Since there are so many things that are powered from the USB port I wonder why all USB ports don't supply a slightly higher voltage (5.2) to compensate for voltage drops or allow for device end voltage sensing.
Searching the net, finds this is a widespread issue, and one person claimed 5.15v was the magic level S7 needed to see - and I guess they also do a droop test as well.
The HP charger + Cable is fine, so it must do as you suggest, and start > 5.15V