ATtiny85 putting out low current on PB4

does anyone know why my attiny is putting out low current on one pin
Im trying to build a solar tracker with an ATtiny85 got the circuit built
It looks ok and works ok except it starts sputtering when PB4 is activated
I measured the current with NOTHING connected and PB4 puts out 6.5ma
and PB1 is putting out 46ma i tried three diffrent ATtiny’s and getting close
to the same current readings…Here is the program I wrote

/*
 * ------------------------------------------------------use-ATtiny25/4585------------------------
 *---------------------------------------------------WORKS-FOR-LINEAR-ACTUATORS--------------------
 *--------------------------------------------This-would-work-as-small-as-an-ATtiny25--------------
 *------------------------------------------ NEEDs--Hbridge--to-control--linear-actuator-----------
 *
 * -------Arduino-is-the-outter-most-pins------
 *----------- ATtiny13/25/45/85-pinout---------
 * ------------RESET--OO     O-------VCC-------
 * --POT--3----A3/PB3-O      O--PB2/-SCK/A1---2--LDRs
 * --OUT--4----A2/PB4-O      O--PB1/-MISO-----1--OUT
 * -------------GND----O      O--AREF/MOSI-----0--5Vref
 * 
 * ---For-AREF-use-LM336Z-5.0--pretty-accurate!
 * 
 */
float read_POT;//POT read-2-to-adjust-threshold-for-light-level
float read_LDRs;//LDR read-7-to make decision of which way to turn
float Vthresh = .050;// Add 30 millivolts works but can be changed 

void setup() 
{
//no need to make analog pins inputs analogRead takes care of that 
analogReference(EXTERNAL);
pinMode(1,OUTPUT);
pinMode(4,OUTPUT);
}

void loop() 
{

read_POT =  analogRead(A3) * (5.0 / 1023.0);
read_LDRs = analogRead(A1) * (5.0 / 1023.0);

//---------------------------MAKE-DECISIONS-BASED-ON-READINGS-----

if(read_LDRs < (read_POT - Vthresh)){digitalWrite(1,HIGH);digitalWrite(4,LOW);}
else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

if(read_LDRs > (read_POT + Vthresh)){digitalWrite(1,LOW);digitalWrite(4,HIGH);}
else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

if(PORTB == 0b00010010){PORTB = 0b00000000;}//--if pins PB1 and PB4 are high automaticly shuts them off 

//------------------------------------------------------------------
}

What kind of load are you trying to drive? The pins don't put out current, current is drawn by the load. What are you trying to do and maybe we can help.

well Im supplying plenty of current to the 85 ..three 7805s ....Im having this problem even with the uC not in the circuit ..I tried three different attiny85s and get very close to the same results ..That leads me to believe
The problem is in my my program..even when i have it on a breadboard The PB4 LED glows dim
and the PB1 LED will blind you ....does anyone see any faults in the program ?

bandmwhitt2013:
does anyone see any faults in the program ?

On nearly every line. But let’s start with hardware. You should NOT measure “current provided by pin” in a way you probably did - connect one probe of DMM to the pin and the other to GND (or 5V). It will short circuit the pin with good chance to damage it. Also you should not connect heavy load to a pin. 5 mA from a pin is OK, 10mA is not so bad but more than 20mA - only if you know what you are doing.
You should NEVER connect LED to the pin without current limiting resistor - unless you know what you are doing (and even in that case something else must provide current limiting for the LED).

read_POT = analogRead(A3) * (5.0 / 1023.0);

is poor - if possible you should not use floats, you should keep it in integer (avoid /1023 and multiple treshold with 1023 instead; 1024 is faster than 1023 because it is power of 2 and in some sense it is more “correct”). It is only minor nuisance making your code slightly slower.

if(read_LDRs < (read_POT - Vthresh)){digitalWrite(1,HIGH);digitalWrite(4,LOW);}
else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

if(read_LDRs > (read_POT + Vthresh)){digitalWrite(1,LOW);digitalWrite(4,HIGH);}
else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

is the real problem. Let assume read_LDRs<(read_Pot-Vthresh). Then pin 1 is set HIGH and pin 4 LOW. In a moment the other if is executed and the condition is false - so both pins are written LOW - pin 1 was HIGH only briefly. Then loop jumps to the beginning. Pot and LDR is read (it takes LOT of time) and (complicated) calcuclations are made. All the time both pins are LOW. After this the first if is executed, condition is true and pin 1 is written HIGH until the second if is executed… The result is pin 1 is written HIGH for only very short time and then iit is written LOW again.
On the other hand if read_LDRs>(read_Pot+Vthresh) the pin 4 is written HIGH and stays HIGH for all the looong time analog reads are taken and calculations are made. Then else condition of first if takes it LOW briefly and it is again written HIGH.

Did you measure current from 5V to pin 1 and pin 4? From the previous this current should be high all the time on pin 1 (with little effect of LDR and POT value) but low on pin 4 while read_LDRs>(read_Pot+Vthresh).

if(PORTB == 0b00010010){PORTB = 0b00000000;}

In such short code you can see this can never happen. If the code were longer and both pins HIGH would lead to dangerous situation this is poor form of “protection”.

thank you smajdalf ..do you have any suggestions on how i should fix it ?

bandmwhitt2013:
thank you smajdalf ..do you have any suggestions on how i should fix it ?

Remove the else statements, it should work as expected. But YOU must ensure the pin does not provide too much current - if you short circuit a pin it will happily provide as much current as it can until something in the chip dies. As note in the code says: "NEEDs--Hbridge--to-control--linear-actuator".

ok will do.. Ill let you know how it works out ..I have 330 ohm resistors on outputs to leds as of now
when it is in circuit Im using 1K

well i did this

/*
 * ------------------------------------------------------use-ATtiny25/45/85------------------------
 *---------------------------------------------------WORKS-FOR-LINEAR-ACTUATORS--------------------
 *--------------------------------------------This-would-work-as-small-as-an-ATtiny25--------------
 *------------------------------------------ NEEDs--Hbridge--to-control--linear-actuator-----------
 *
 * -------Arduino-is-the-outter-most-pins------
 *----------- ATtiny13/25/45/85-pinout---------
 * ------------RESET--OO     O-------VCC-------
 * --POT--3----A3/PB3-O      O--PB2/-SCK/A1---2--LDRs
 * --OUT--4----A2/PB4-O      O--PB1/-MISO-----1--OUT
 * -------------GND---O      O--AREF/MOSI-----0--5Vref
 * 
 * ---For-AREF-use-LM336Z-5.0--pretty-accurate!
 * 
 */
float read_POT;//POT read-2-to-adjust-threshold-for-light-level
float read_LDRs;//LDR read-7-to make decision of which way to turn
float Vthresh = .050;// Add 30 millivolts works but can be changed 

void setup() 
{
//no need to make analog pins inputs analogRead takes care of that 
analogReference(EXTERNAL);
pinMode(1,OUTPUT);
pinMode(4,OUTPUT);
}

void loop() 
{

read_POT =  analogRead(A3) * (5.0 / 1023.0);
read_LDRs = analogRead(A1) * (5.0 / 1023.0);

//---------------------------MAKE-DECISIONS-BASED-ON-READINGS-----

if(read_LDRs < (read_POT - Vthresh)){PORTB=0b00000010;}
//else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

if(read_LDRs > (read_POT + Vthresh)){PORTB=0b00010000;}
//else{digitalWrite(1,LOW);digitalWrite(4,LOW);}

if(PORTB == 0b00010010){PORTB = 0b00000000;}//--if pins PB1 and PB4 are high automaticly shuts them off 

//------------------------------------------------------------------
}

Now ....the led on PB1 won't go off unless the Led on the positive rail is completely covered

And how your circuit looks? Measure all interesting voltages with DMM, it may help you.

if anyone has the components(parts) to build this circuit please do so and Test ..then you will see my problem
i use a USBASP to program my controllers ..arduino works but this is a little more practical

bandmwhitt2013:
if anyone has the components(parts) to build this circuit please do so and Test ..then you will see my problem
i use a USBASP to program my controllers ..arduino works but this is a little more practical

But we don't know how your circuit looks. Post a schematic please.

/*
 *
 * -------Arduino-is-the-outter-most-pins---
 *----------- ATtiny13/25/45/85-pinout-----
 *-----------------------------------------
 * --------------------00     0--VCC--------
 * ----GND-LED-330R--0      0-330R-LED-GND 
 * ------------LEDRs--0      0--POT--------
 * ------------GND----0      0--VREF------- 
 * 
 */

This is how it is connected to the bread board

i have TinyCad to draw schematics but I can't get the picture to show up on here

I am 99% sure it is in my program like I say I built this on a breadboard and have the same result ..
AHHHH..thanks..i figure it out

well Im still stumped !!!

i am still stumped ? I have did this before and got the algorithm rite but this time I cant figure it out

Well what is it SUPPOSED to do?

bandmwhitt2013:
This is how it is connected to the bread board

And how is connected the LDR and POT?