pulldown on output?
- Thread starter kakolon
- Start date
Post the circuit.
Tell us the PIC.
Give us a clue.
My car won't start... why not?
Help us. Our crystal balls are bursting. And Uri Geller is on holiday.
In many cases a PIC will have more variety of I/O on pins.
Without more information it is impossible to define whether an equivalent PICAXE can act as a direct substitute.
Tell us the PIC.
Give us a clue.
My car won't start... why not?
Help us. Our crystal balls are bursting. And Uri Geller is on holiday.
In many cases a PIC will have more variety of I/O on pins.
Without more information it is impossible to define whether an equivalent PICAXE can act as a direct substitute.
inglewoodpete
Senior Member
I have used a PICAXE as a pseudo open collector output by adding a diode in series with the output (cathode towards the PICAXE output).
However, this will only work properly if the whole circuit is switched off the same power supply (the PICAXE can keep running from power from the pullup resistor).
However, this will only work properly if the whole circuit is switched off the same power supply (the PICAXE can keep running from power from the pullup resistor).
Ok ok ! Don't be such a comedian! will you, Dippy. You end up being rude
To be honest, I thought that the matter would be simple to understand without adding too much information.
By the way I figured out the problem myself. I was doing some bad measures on the circuit, the outputs work just as they have to.
Next time just say "Please add more information to help us understand", that’s it. Leave the other comments to yourself, nobody forces you to help.
Best regards,
Kakolon
To be honest, I thought that the matter would be simple to understand without adding too much information.
By the way I figured out the problem myself. I was doing some bad measures on the circuit, the outputs work just as they have to.
Next time just say "Please add more information to help us understand", that’s it. Leave the other comments to yourself, nobody forces you to help.
Best regards,
Kakolon
Post the circuit.
Tell us the PIC.
Give us a clue.
My car won't start... why not?
Help us. Our crystal balls are bursting. And Uri Geller is on holiday.
In many cases a PIC will have more variety of I/O on pins.
Without more information it is impossible to define whether an equivalent PICAXE can act as a direct substitute.
I was teasing you.
OK then; "Please add more information to help us understand",
The reason I say this is twofold.
1. You asked "How can the PIC send to 0v the outputs".
Note (based on years on this Forum): Many people say "PIC" when referring to "PICAXE".
To make a PIC "send" 0V to an output , for most Port.pIns, you have to set the TRISx register, switch off the ADC where appropriate, and then set the specific Potx.bit to zero.
To make a PICAXE "send" 0V to an output depends on WHICH PICAXE you use.
You may have to set the direction first, or not, depending on which PICAXE and then use a Low command.
These methods, in effect, ground the desired pin. i.e. "send 0v".
2. The "electronic device". There are dozens of different PICs , there are not so many PICAXEs. Some PICAXEs have fixed Output and Input pins. Unless you are experienced with Poking your choice may be limited and even then, I believe, the option to change is not universal. So, without the information we can't suggest a PICAXE equivalent.
Without telling us the desired I/O pins of this "electronic device" it is IMPOSSIBLE to say 100% whether you can directly swap out with a PICAXE.
It could be dead easy...
So, let me be precise;
1. What PIC is in this "electronic device". e.g. 16F88.
2. Which PIC pins are connected to these pullups that you wish to set Low?
3. And these particular pins; are they definitely pulled up by external components? Resistors? Logic?
4. Or are they pulled up by the internal PIC 'weak pullups'?
5. Or are the pins set High by the PIC?
If 'Yes' to either Q3 or Q4 then it implies that the pins might also be set to 'Input' more by the PIC's code. Sometimes referred to as tri-stating.
The solution may be dead easy, but without more information we are in guessing territory.
If someone just says "yeah, just stick in a such and such" and it went POP you'd be a little annoyed.
OK then; "Please add more information to help us understand",
The reason I say this is twofold.
1. You asked "How can the PIC send to 0v the outputs".
Note (based on years on this Forum): Many people say "PIC" when referring to "PICAXE".
To make a PIC "send" 0V to an output , for most Port.pIns, you have to set the TRISx register, switch off the ADC where appropriate, and then set the specific Potx.bit to zero.
To make a PICAXE "send" 0V to an output depends on WHICH PICAXE you use.
You may have to set the direction first, or not, depending on which PICAXE and then use a Low command.
These methods, in effect, ground the desired pin. i.e. "send 0v".
2. The "electronic device". There are dozens of different PICs , there are not so many PICAXEs. Some PICAXEs have fixed Output and Input pins. Unless you are experienced with Poking your choice may be limited and even then, I believe, the option to change is not universal. So, without the information we can't suggest a PICAXE equivalent.
Without telling us the desired I/O pins of this "electronic device" it is IMPOSSIBLE to say 100% whether you can directly swap out with a PICAXE.
It could be dead easy...
So, let me be precise;
1. What PIC is in this "electronic device". e.g. 16F88.
2. Which PIC pins are connected to these pullups that you wish to set Low?
3. And these particular pins; are they definitely pulled up by external components? Resistors? Logic?
4. Or are they pulled up by the internal PIC 'weak pullups'?
5. Or are the pins set High by the PIC?
If 'Yes' to either Q3 or Q4 then it implies that the pins might also be set to 'Input' more by the PIC's code. Sometimes referred to as tri-stating.
The solution may be dead easy, but without more information we are in guessing territory.
If someone just says "yeah, just stick in a such and such" and it went POP you'd be a little annoyed.
Kakolon: Learn to handle comments my friend, they are all well meant, take this senstence from Dippy....
That is SO TRUE is it not... common, you came here for help, like I also do and I do it a lot more it seems (you - 50 posts, me - 500+ posts) and 499 of mine were questions... I have learnt to think about my question and to provide AS MUCH AS POSSIBLE info to the forum. You know what ? Even then the guys says "what about this..... that...." which I did not include as info. It is VITAL that we supply that info in order to get a good answer, otherwise we are just wasting every body's time, including your own (less important) but the forum experts are loaded with questions already, they do us newbies (you included) a BIG FAVOUR, see it in that light and ESPECIALLY LEARN how to handle Dippy's remarks, he must be one of the BETTER educators out there as he tries to teach "how to think" to a world that DOES NOT THINK anymore..... I mean, take google for instance.... this just in defence for the guys that helped me so much already.......If someone just says "yeah, just stick in a such and such" and it went POP you'd be a little annoyed
I’m 100% with you on providing the information needed to answer the question, as I said, I thought the answer could be simple, It was just the way he answered me that annoyed me. That's it.
I'm a silent reader of this forum for more than 4 years, I don't frequently post because every time I got a question, searching on the forum lets me get the information that was already asked and responded, and I don't replay questions, because I'm below the technical knowledge that most of the guys that make reply have.
Best regards,
kakolon
I'm a silent reader of this forum for more than 4 years, I don't frequently post because every time I got a question, searching on the forum lets me get the information that was already asked and responded, and I don't replay questions, because I'm below the technical knowledge that most of the guys that make reply have.
Best regards,
kakolon
Kakolon: Learn to handle comments my friend, they are all well meant, take this senstence from Dippy....
That is SO TRUE is it not... common, you came here for help, like I also do and I do it a lot more it seems (you - 50 posts, me - 500+ posts) and 499 of mine were questions... I have learnt to think about my question and to provide AS MUCH AS POSSIBLE info to the forum. You know what ? Even then the guys says "what about this..... that...." which I did not include as info. It is VITAL that we supply that info in order to get a good answer, otherwise we are just wasting every body's time, including your own (less important) but the forum experts are loaded with questions already, they do us newbies (you included) a BIG FAVOUR, see it in that light and ESPECIALLY LEARN how to handle Dippy's remarks, he must be one of the BETTER educators out there as he tries to teach "how to think" to a world that DOES NOT THINK anymore..... I mean, take google for instance.... this just in defence for the guys that helped me so much already.......