Hi
I am newbie to embedded system. Need input on how configure a gpio pin on microcontroller. Our micro controller's gpio pin is connected to an external circuit pin which is configured as active low when there is an interrupt. This line act as interrupt line. My question is whether I need to configure gpio pin as pullup or pulldown. if i configure it as level triggered what should be the interrupt polarity.

 

Welcome to AAC!

I am newbie to embedded system. Need input on how configure a gpio pin on microcontroller.

The first thing we need to know is what microcontroller.

Our micro controller's gpio pin is connected to an external circuit pin which is configured as active low when there is an interrupt. This line act as interrupt line. My question is whether I need to configure gpio pin as pullup or pulldown. if i configure it as level triggered what should be the interrupt polarity.

Is this homework?

 

Welcome to AAC.

Does it occur to you that we might need to know what μC type or number you are using?

 

Hi
I am newbie to embedded system. Need input on how configure a gpio pin on microcontroller. Our micro controller's gpio pin is connected to an external circuit pin which is configured as active low when there is an interrupt. This line act as interrupt line. My question is whether I need to configure gpio pin as pullup or pulldown. if i configure it as level triggered what should be the interrupt polarity.

If the interrupt pin is ACTIVE-LOW, you need a pull-up resistor, external or on-chip.

 

The 12f series of Picmicro has a input that can be set to either INT on Hi or Low transition, others Interrupt on Change.
Max.

 

Welcome to AAC!
The first thing we need to know is what microcontroller.
Is this homework?

Microcontroller is Maxim 32550

 

Welcome to AAC.

Does it occur to you that we might need to know what μC type or number you are using?

Microcontroller is Maxim 32550

 

Nobody here has the datasheet for it.

Fill the NDA and get the whole datasheet.

 

Hi
I am newbie to embedded system. Need input on how configure a gpio pin on microcontroller. Our micro controller's gpio pin is connected to an external circuit pin which is configured as active low when there is an interrupt. This line act as interrupt line. My question is whether I need to configure gpio pin as pullup or pulldown. if i configure it as level triggered what should be the interrupt polarity.

So your a newbie? is this a newbie to micro's in general or just hacking ATM machines?
BTW its old tech,also they got wise to fake inserts, you wont trigger a card read. TBH its alot easier to hire a fork lift truck and rip the thing out the wall.

 

So your a newbie? is this a newbie to micro's in general or just hacking ATM machines?
BTW its old tech,also they got wise to fake inserts, you wont trigger a card read. TBH its alot easier to hire a fork lift truck and rip the thing out the wall.

How did you know OP is hacking ATM's ?

 

How did you know OP is hacking ATM's ?

Ages ago crooks placed an insert into ATM machines, you would put your card in and pin number. the machine would tell you it had a fault and you would go to another machine. The way it worked was by pulling the line low it invoked a false fault condition on the machine, but the card reader (the thing they inserted) had read your details for cloning the card, had it not given a fault response then the ATM would know the card was being read etc.

Thats the rough explanation, actually the other give away is the language used. Real noobs dont have as much tech knowledge as pull ups and pull downs etc. What the OP really wanted to know was, how do you know when to twiddle the line without causing an alarm condition. I suspect they tried one and found the machine went into lock down.

How do I know about it? Their is rumoured to be places on internet where videos from black hat reside, these videos are not the ones that make you tube.

Actually if you want the full datasheet it isnt that hard to find! The OP is also out of date, the hole was closed a long time ago, you need a matched pair now, your card pairs with every ATM it enters.

 

How did you know OP is hacking ATM's ?

My guess comes from the Maxim 32550 data sheet, first paragraph:

General Description
DeepCover® embedded security solutions cloak sensitive
data under multiple layers of advanced physical security
to provide the most secure key storage possible.

 

My guess comes from the Maxim 32550 data sheet, first paragraph:

General Description
DeepCover® embedded security solutions cloak sensitive
data under multiple layers of advanced physical security
to provide the most secure key storage possible.

Yes but the toggle question only applies to ATM's .

The chip is also used in POS systems, but with POS you buy something so someone else is present....... ATM's are the only place that pin comes into play.

 

Without a datasheet we can't do more than speculate on solutions or motivations. We are not going to get the datasheet because it can't be disclosed in public. It is unfair to imply that the TS has ulterior motives. Given all of that it is pointless to continue so this thread is closed.