PWMOUT and 18X problem
- Thread starter ashleyps
- Start date
premelec
Senior Member
Hippy... for reliable operation I'll have to disagree with you about floating inputs - especially on solderless breadboards where there is considerable capacitance between adjacent contacts [large area of metal connected to each pin]. This especially true of dynamic situations - i.e. PWMOUT where high speed repetitive events occur. This poster says he can HIGH & LOW the pin but PWMOUT doesn't work... That leads me to conclude that there is possible dynamic effect with the PWMOUT either through the power supply pins or inter-pin capacitance... Whatever.. it seems worth the small effort to clean up this aspect of the breadboard... Floating inputs also pickup AC and RF from the electromagnetically energetic environment almost all of us now live in... With CMOS logic undefined inputs can result in high currents depending on the chip and design. I have many years experience in hardware work - less in programming for which you are certainly expert! Thanks for your continued help to us all... Happy prosperous reliable PICAXE New Year...
BeanieBots
Moderator
premelec,
Whilst I agree that leaving inputs on a PICAXE floating is not a very clever thing to do and will indeed result in higher current draw, it should NOT cause the PICAXE to behave incorrectly unless one of those inputs is either serin or reset. Can also effect readadc values but should not be the issue here.
Try it anyway. One less thing to worry about.
ashleyps,
You say you tested Hippy's code but not what the outcome was.
Have you tried with the LED in both pull-up and pull-down configurations?
Looking closely at your picture, I can see a green? wire going to pin 4, but don't see how that can be connected to the 4k7 pull-up.
Whilst I agree that leaving inputs on a PICAXE floating is not a very clever thing to do and will indeed result in higher current draw, it should NOT cause the PICAXE to behave incorrectly unless one of those inputs is either serin or reset. Can also effect readadc values but should not be the issue here.
Try it anyway. One less thing to worry about.
ashleyps,
You say you tested Hippy's code but not what the outcome was.
Have you tried with the LED in both pull-up and pull-down configurations?
Looking closely at your picture, I can see a green? wire going to pin 4, but don't see how that can be connected to the 4k7 pull-up.
Last edited:
Hi BeanieBots,
I'm not very sure about "LED in both pull-up and pull-down configurations" means (I'm a Newbie) but I made the following:
1.- I have download this code to my picaxe
PwmOut 3 , 249 , 249
Do : Loop
2.- Led+R connected: (Pin9 > Resistor > +Led- > 0V) Result: Led OFF
3.- Led+R connected: (Pin9 > Resistor > -Led+ > +5V) Result: Led ON 100% but is the same result if I connect it to any ouput
I'm trying to be graphical, because my english is a little bit basic
I'm not very sure about "LED in both pull-up and pull-down configurations" means (I'm a Newbie) but I made the following:
1.- I have download this code to my picaxe
PwmOut 3 , 249 , 249
Do : Loop
2.- Led+R connected: (Pin9 > Resistor > +Led- > 0V) Result: Led OFF
3.- Led+R connected: (Pin9 > Resistor > -Led+ > +5V) Result: Led ON 100% but is the same result if I connect it to any ouput
I'm trying to be graphical, because my english is a little bit basic
BeanieBots
Moderator
Well, you understood about the LED connections OK.
The circuit in your 2nd photo is quite different to your first.
Using high & low commands, does the LED work in both connection methods with this program.
do
high 3
pause 500
low 3
pause 500
loop
If this still works for both ways of connecting the LED but the code posted by hippy for PWM does not work, then quite frankly, I have absolutely no idea. (assuming reset & serin are wired correctly).
The circuit in your 2nd photo is quite different to your first.
Using high & low commands, does the LED work in both connection methods with this program.
do
high 3
pause 500
low 3
pause 500
loop
If this still works for both ways of connecting the LED but the code posted by hippy for PWM does not work, then quite frankly, I have absolutely no idea. (assuming reset & serin are wired correctly).
I have tested and work fine in both ways.
BeanieBots
Moderator
Then you have a very unique 18X
Up to date firware (8.6).
Output 3 works fine in both directions.
Programs OK. (No verification error)
Yet PWMout does not work.
Don't see how that can be possible, yet you have one.
You are the ONLY person to have one of those. Makes it valuable.
I'd hang on to it as a collectable but you might want to send it back to your supplier.
Up to date firware (8.6).
Output 3 works fine in both directions.
Programs OK. (No verification error)
Yet PWMout does not work.
Don't see how that can be possible, yet you have one.
You are the ONLY person to have one of those. Makes it valuable.
I'd hang on to it as a collectable but you might want to send it back to your supplier.
Very, very odd. I am bereft of ideas except suggesting a swapout.
I'm sorry to hear that you are having such problems.
Well, it looks like you should buy another PICAXE, preferably 2.
Never buy just one of anything when the cost is so small.
When prototyping you've got to remove as many variables as possible.
This includes duff components and duff handling.
(In this case, having 2 PICAXEs may have saved days of time, and carriage costs too perhaps. This isn't 20/20 hindsight, just a bitta common).
Good luck with sending it back to supplier.
I'm sorry to hear that you are having such problems.
Well, it looks like you should buy another PICAXE, preferably 2.
Never buy just one of anything when the cost is so small.
When prototyping you've got to remove as many variables as possible.
This includes duff components and duff handling.
(In this case, having 2 PICAXEs may have saved days of time, and carriage costs too perhaps. This isn't 20/20 hindsight, just a bitta common).
Good luck with sending it back to supplier.