Questions tagged [attiny85]

ATtiny85 is small, low-power 8-bit, 8-pin RISC microcontroller from Microchip.

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NPN transistor to turn ON an ATTiny85 from a pinout of an ATTiny85

I have 2 ATTiny85 and a NPN CS-9011 used as a switch. They are both powered by the same 3.3V. I use pin 1 to run the base of the transistor with a 1K resistor. This is not working after an afternoon ...
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ATTiny85 Use external crystal for timer but not system clock

I'm working on a project using an ATTiny85 where I need a precise timer. I have some 32kHz crystals, which it looks like would work fine if I ran the system clock off of them and made the timer take ...
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How would I activate an ATtiny85 microcontroller using a transistor?

I am using a TIP120 transistor and an ATtiny85. The RF signal goes into the base. I want to then activate the ATtiny85 to run code. However, my circuit starts running code without an RF signal going ...
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Need to monitor an SSR with an arduino

I need to monitor the coil side of an SSR (not actually a coil I know). The problem with my circuit is it allows enough current through the resistor divider to 0V to actually turn on the SSR. Just ...
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How to program attiny85 on-board without separate leads?

Another newbie question. I’m planning on ordering my first ever printed PCB that would be a simple 3 mm LED driver controlled by a ATtiny85. Now… I could program the chip using a SOIC-8 to DIP-8 ...
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3 answers
2k views

Do I need a capacitor for an ATtiny85?

I have a small LED strip light, which I want to power by a power bank. It is active for 6 hours, and then sleeps for 18 hours. It takes almost no power while sleeping, and the power bank detects this ...
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ATtiny85 sharing SPI and I2C pins

I have an ATtiny85 sending messages via LoRa over SPI and I've hooked up a BME280 on I2C which I'm using with the TinyBME280 library. Everything is fine until I read the temperature, which then hangs ...
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Attiny85 Burn Bootloader Error [Device signature = 0x000000] [SOLVED]

I had read in different forums about similar issues and double-check the connections and datasheet. But it's still not working for me. First of all, I will share my build and my configuration. Later ...
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Faster Timer0 overflow than 2 ms on Attiny85

I'm trying to get a Timer0 overflow with an overflow every 500us, but can't find a solution to get it so low. I'm running the Attiny85 on its internal 1 MHz clock, so I know it is not gonna be the ...
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Powering an ATtiny85 from the pull-up resistor of another device

I have an interesting design challenge. Reed switch S1 is feeding pulses at a maximum of five per second into a 3.3 V microcontroller input. I want to halve the pulse rate. I don't have access to the ...
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ATtiny85 and MLX90614 cannot read temperature data

I'm trying to read sensor data from an MLX90614 using an ATtiny85 to turn on some LEDs if the temperature is in the corresponding temperature range. Right now, all my readings are under 0 degrees. I ...
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Best way to detect any combination of keypresses with few pins? (not just single key presses)

I ask for the "best" way, but a "typical" way or a "better" way will be appreciated. A great way to detect a single keypress among a bunch of buttons is to use a resistor ...
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ATtiny85 - Sleep Mode & Interrupts

I am working with ATtiny85. I want to put my MCU in IDLE Sleep mode and after every five minutes, I want to write data into EEPROM. I am using Timer 0 overflow interrupt to count 5 mins. Counting will ...
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Serial.println() - ATtiny85

I have a standalone device with ATtiny85 MCU running Arduino firmware. In the firmware there are serial.println() functions that write its status to the serial port. Since it is a standalone device ...
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ATtiny85 - Working with EEPROM in IDLE mode

I am working with the ATtiny85 board. I am working with data EEPROM and sleep modes of EEPROM. I have the following questions Can we write data into Data EEPROM of ATtiny85 when the device is in IDLE ...
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Can't burn bootloader or upload code through Arduino IDE to attiny85 using USBasp

I've wired everything up on a breadboard using the datasheet of the attiny85 and the 10 pin layout of the isp programmer, installed the libusb-win32 USBasp driver through ZADIG, and setup attiny85 ...
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Debugging with ATMEL-ICE in Ubuntu using cutecom

I have an Atmel-ICE-C that I've been using successfully within Ubuntu 18 to program a custom board based on the attiny85 using the terminal and the necessary libraries. I can use a command like this ...
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Connecting Attiny85 to nRF24IO1: How can I get 2 free IO pins in attiny85

I am trying to connect an Attiny85 to an nRF24L01. I tried the library NRFlite from the Arduino IDE libraries and it works fine. The problem is that I end up with only 1 free analog pin (pin 4) in ...
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Why doesn't the Attiny85 work in this circuit?

I'm designing a circuit to control the power of a heater using an Attiny85. This is the circuit: The Attiny85 is programmed to boot with the heater and mosfet turned off. When the button is pressed, ...
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Is there any flaws with this Attiny 85 schematic?

I was wondering if there is anything I am missing in this Attiny85 schematic. It will be first burned with the Arduino bootloader through the pins. I am making something similar to the DigiSpark ...
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Schottky diode polarity attiny85 dev board

This dev board, forgive my second question on it today. My question is regarding the Schottky diode. It looks to me like the USB 5V is wired to the cathode. Wouldn't that mean it would only allow ...
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Why is there a 5V linear regulator on this USB ATTiny85 dev board?

This dev board. 78M05G regulator, attiny85 MCU. Similar (ON MC78Mx05) regulators' dropout voltage is listed at 2V0. USB voltage is specified at 5V0 (+0V25)(-0V55). The ATTiny85 can take 2V7 to 5V5, ...
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2 votes
1 answer
142 views

C++ AVR microcontroller optimization problem

I'm faced with a weird problem. I'm developing a program for AVR. Microcontroller ATtiny85. Frequency 1 MHz. Programmer ...
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ATtiny85 Yikes Error While Burning Bootloader

I'm using an Elegoo uno to burn the ArduinoISP example code on to an ATtiny85 SMD. I wired the board according to the "#define USE_OLD_STYLE_WIRING" using pins 13/12/11/10. The wiring ...
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Why doesn't USB power the circuit?

I am absolutely new to electrical stuff, and I am just trying to create my first project. I am basically trying to drive a strip of RGB LEDs (in a form of a Christmas tree) using attiny85. I have ...
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Attiny85 Serial Transfer INT from Teensy 4.1

Goal: Transfer incoming Analog Pot Data into Attiny85, convert to INT and send it out to Teensy 4.1 to read. I have programmed my ATTiny85 to handle a 7 Segment LED (partial code below). It takes the ...
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933 views

Protecting circuit from piezoelectric disc voltage spike

I have a piezoelectric disc, and I'm trying to use to build a primitive sonar. I connected the disc to an oscilloscope and if I press very hard on the disc, I see that the voltage can spike pretty ...
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Controlling mosfet with a battery-powered attiny85

I have to control a MOSFET in switch mode. However, the whole circuit including AtTiny is powered by a LiPo battery. AFAIK AtTiny's output pin voltage is somewhere between 0.8*Vdd and Vdd and I'm ...
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LED intensity issues on Attiny85 with 74HC595 to control 8 LEDs

I want to light up 8 LEDs where I should be able to control intensities of the LEDs as well. Since I want the circuit to be as small as possible on a printed circuit board (PCB,) I am using an ...
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Reading 14V PWM signal on Attiny85

I want to read the 14V PWM signal on Attiny85 running an Arduino IDE. It is a control signal sent from the car's PCM to the cooling fan. The frequency of thes signal is 120Hz while the duty cycle is ...
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239 views

Generating variable frequency PWM with Attiny85

Bit of Background: I am currently working with my ATX Power Supply and trying to re-purpose it to use its voltage outputs (3.3V, 5V and 12V). But I would like to have a PWM feature with my power ...
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Issues using a 74LS245 with Attiny85

I have a Raspberry Pi, a 74LS245, and an ATTiny85. I connected the Pi to the Tiny through 1k resistors, and am able to use SPI to program it, no problem. I have added a 74LS245 inbetween, to ...
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3 votes
2 answers
1k views

Understanding gate threshold voltage of logic level mosfets from datasheet

I want to build an Arduino Project to control a DC load(DC 5V water pump ampere rating is not known) and using a transistor with PWM to control speed. There is a need to shrink down the project and I ...
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ATX power supply turns off when used with DIY boost converter

I am trying to build my own step-up boost converter. I have my connections as shown in the following schematic (except for the one circled in red.) First I powered up my step-up module with a ...
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Using analogRead() with ATtiny85

I'm new the ATtiny series of Atmel MCUs and I've been trying to build a DC-DC boost converter with an ATtiny85-20PU recently. To get started I've been trying to control the brightness of two LEDs by ...
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ATTINY85 and NRF24L01+ only works with longer vcc/gnd lines on PCB

So I've been banging my head for a couple weeks on this, but I need some help. I'm trying to build something small and battery powered. I have a handful of ATTiny85's and NRF24L01+'s. I have ...
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ATtiny85 pulses its pins at about 10Hz after some kind of programming/wiring messup

I have an ATtiny85 which had a simple program PWMing its output pins to pulse some LEDs. While messing round trying to wire up Raspberry Pi SPI to program it with avrdude, it's gone into a state ...
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1 answer
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How do I communicate with an ATtiny85 development board that has V2.2 bootloader?

I'm very new to this so go easy. I'm trying to download a program to an ATtiny85 development board with a microUSB connection. All the posts I've read keep referring to a much older IDE version. I ...
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1 vote
1 answer
208 views

Digispark: Driving high Zener-connected pin on ATtiny85

In my project I need all available pins on my Digispark. Pin PB4 is connected to a 68 Ω resistor and a 3.6 Zener diode. This pin is used for USB protocol. This means that at some point in time ...
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2 votes
1 answer
581 views

Programming an attiny85 and powering a circuit over a single USB-C port

I'm currently working on a RGB enabled controller stand that will include a circuit that does do two things: -charge the controllers -control rgb strips on the mount I'm pretty new to electronics, and ...
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1 answer
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Attiny85 for wireless communication

I'm a very beginner in electronics. I'm trying to make a system which transmits a tank chemical level to a distant system. Remote system is an Arduino. For the tank unit I have 4 float switches. ...
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1 answer
461 views

What is a proper way to send information from an HC-05 (Bluetooth module) to a phone?

I have 12 simple touch sensors and each of them produces an analog output. I want to send that information to a phone (or some other device). To do that I would need to use the HC-05 Bluetooth module. ...
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230 views

ATTiny85 clock speed problem

Using an ATTiny85 and an Arduino loader I created a simple device for turning on an exhaust fan based on a light sensor. The ATTiny85 turns on the fan after activating a warning light and sounding an ...
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PWM to analog voltage conversion for communication between two microcontrollers

I want to use this schematic for sending PWM signals from an STM32F0 Arm microcontroller to an ATtiny85. I want to convert the PWM signal to a proper analog voltage, so that the ATtiny analogRead() ...
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What is the proper way to reset attiny85?

I have 3 attiny85 on my pcb. And I want to have software controlled reset for them. A separate STM32F0 microcontroller is responsible for the reset. I have two states from the STM32F0 to pull up and ...
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Is this circuit ok for MCP9700 temp sensor?

I am trying to use multiple MCP9700 temperature sensors and probe certain power IC heatsinks for sensing the temperature through an attiny85. I have two parts in the overall schematic. For each ...
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Questions regarding voltage divider for micro controller sensing

I am beginner trying to develop two voltage sensors for attiny85 microcontroller. I have two separate voltage levels that I want to sense using the attiny. One of the voltage supply is 0V-5.5V and is ...
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2 votes
1 answer
336 views

Controlling Mosfet with ATTiny85 and IR Reflective Sensor

My plan is to start a motor, then stop the motor when the gear teeth gets to 15 (out of 16) I will be able to tell at what position the gear is by placing an IR reflective sensor under the teeth. The ...
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368 views

Does Attiny13 pull a lot more current in sleep mode than Attiny85 or did I do something wrong?

First off here is the code I have tested on both Attiny13A and Attiny85V: ...
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260 views

Serial Communication Between Android and Attiny85

I am planning to build a sensor module for smartphone using Attiny 85 as its microcontroller. The sensor module will have a USB type A and to connect to the smartphone, OTG is required. Serial ...
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