attiny85 lcd display in stock

Using an LCD on a small chip like an attiny85 is not really that hard and till recent I didnt even think it warranted an instructable, but I have received questions about it, so I may as well expand on the process.

With the attiny only having a max of 6 pins available, it goes without saying that it cannot directly control all the pins of the standard Hitachi based LCD"s

A little bit over a year ago, I described how to add an LCD to an Attiny or other chip, using only 2 pins. That circuit made use of an HC164 shift register, but as I2C modules for LCD"s are extremely cheap and even LCD"s with a module already in place also are dirt cheap, one might as well use I2C on the Attiny85.

I2CThe attiny85 can simulate I2C on PB2 (pin 7) (SCL) and PB0 (pin 5) (SDA). The "Wire" library that is used to read and write bytes from and to the I2C port on the arduino doesnt work on the attiny. It needs the TinyWireM library to act as an I2C master

The "NewLCD" library from Francisco Malpartida is my favorite library, but also that one fails in using I2C for the Attiny because it makes a call to the Wire library. A modification to make it work with Attiny85 can be found here.

The "Bro Hogan" library however does work. It is basically the same library as the standard arduino LCD library, but it is modified to recognize the Attiny85 and the Attiny2313 and then makes a call to "TinyWireM" rather than "Wire".

Adafruit also provides a libray that works with the Attiny85 and that is described in another instructable. I will be using the Bro Hogan library here.

Most problems you may encounter are related to the IDE getting confused regarding the libraries. If you are using the standard Arduino LCD library, best replace it by the Bro Hogan library. If you are using Malpartida"s library and want to keep that (as it is a great library), move it out of the way. Grab the entire folder and move it out of your sketchbook/libraries folder. Make sure you have the TinyWireM library installed and make sure your libraries are up to date.

Now obviously there is no bootloader for the attiny85, but the process of burning the bootloader sets the fuses of the attiny from factory mode, to the mode you want to use it in. So, presuming you use the Arduino as ISP,:

NOTE: Prior pushing through with this tutorial, I encourage you  (if you haven’t yet) to visit Miniaturizing Your Arduino Project using ATtiny85, which demonstrates how to set up your ATtiny85 with Arduino UNO and Arduio IDE.

I am a bit into programming the ATtiny85 currently, and was looking for some libraries to use for my 16×2 LCD via i2c. I tried testing the current library I had (refer to my previous tutorial : Displaying Text to LCD via I2C Module on DIY Arduino Board), but this does not work with the ATtiny85.

In my previous article, we’ve somehow shown the pinout for the ATtiny85 (in my case the ATtiny85 Development Board, but no much of a difference actually:

IMPORTANT: If tou have a separate power supply for the ATtiny85 IC or Development board, you must connect GND from the Arduino UNO to the GND of the power supply.

Now, connect your Arduino UNO as demonstrated in my previous post. We will use the Arduino UNO as ISP to upload sketches to the ATtiny85 IC or Development Board.

This project demonstrates the ability of the Wokwi Arduino simulator. You can write code on ATtiny85 to drive an LCD2004 (4 rows, 20 column hardware) by yourself. You can learn to program as well as see the code in action. No hardare needed.

The actual manufacture part number is ATTINY85-20PU. It always tends to look like a lot of part numbers, but often it boils down to tape and reel vs tray, temperature ratings, and packaging. Sometimes you will even get different part numbers based on the default configuration (running at the full 20MHz, running at 1/2 clock speed at 10MHz, or using an external crystal for example), even though the actual chip is the same. For their naming convention usually you can find that in the ordering information at the bottom of the datasheet.

Finally the 85 appears. SparkFun is in the U.S., so I"m guessing PIC fan boys. AVRs not on the brain. - I"d like to see an ATtiny parts kit including ATtiny85, 20MHz crystal, crystal caps, bypass cap, and maybe a six pin ISP header. Even if these parts aren"t kitted the related products list below should include them. Nope, now I gotta go hunting; or maybe that"s the idea :-(

I just confirmed that the ArduinoISP can be used to program the SMD SMT version of the ATTiny85 chip. I used the Arduino 0022 IDE and board definitions and older version of the instructions from MIT High Low Tech. (The updated instructions for Arduino 1.0 fail for me.)

I"m trying to control a strip of a single Neopixel with an Attiny85 @ 16Mhz (internal PLL, 4.3 V BOD) but it just doesn"t work. the example "strandtest" just makes the led stuck in green, any help? i"m just connecting the data cable of the neopixel to the Pin 7 (PB2) in the Attiny, i also try putting a resistor in this, but it doesn"t help.ATTINY85

Yep! The ATtiny85 ships with a fuse that makes them operate at internal 1MHz. That fuse can be changed to operate at 8MHz internal. If you need to go above that (or need better precision than the internal oscillator) you can set the fuses to operate with an external oscillator. 20MHz is the maximum external oscillator allowed.

(see: http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=107166&productId=107166&keyCode=WSF&CID=GOOG&gclid=CI2TocLm6rICFexAMgodOU0ALQ for the

Hi all! I"ve recently bought two of these Attiny85 chips. I followed the MIT hi-low tech-group instructions on using Arduino as an ISP to program the chips.http://hlt.media.mit.edu/?p=1229

The ATtiny85 Breakout board is the smallest Arduino Compatible board! It measures less that 1 square inch and has an onboard microUSB port! With 6 I/O pins an onboard voltage regulator and 3 Power Pins, this is a super awesome way to get Arduino based projects into the tiniest of places! Just plug in a microUSB cable to your computer and program using the Arduino software.

If you want to embed a microcontroller into a project and are looking for something smaller and cheaper than an Arduino and you don’t need a lot of I/O pins or code space, the ATtiny85 can be a good solution.

The ATtiny85 is an 8-bit Atmel ATtiny85 MCU from the same AVR family that the Arduino boards are based on.  Though it only has 8 pins, it packs quite a lot of functionality into that small package.

The device can be programmed using the Arduino IDE and much of the standard Arduino software and existing libraries will work with it.  Other libraries have been modified to work properly with the ATtiny85.

The 5V pin can accept a 3.0 – 5.5V input if you want to power the module directly off 5V or a battery pack in that range.  This range is determined by the ATtiny85 chip operating range.  If you are instead using the VIN pin to power the module, then you can use this pin as a 5V output to power a sensor or other device.

When connecting the SPI interface, the pins are cross-connected, so the ATTiny85 MISO pin would connect to the external device MOSI and the ATTiny85 MOSI would connect to the external device MISO.

The I/O port on the ATtiny85 chip is Port B and that is why digital I/O are labeled PB0 – PB5 on the backside of the board (and P0-P5 on the front side).  These correspond to digital I/O D0-D5 on an Arduino and are referenced in the program using just the number as in pinMode(0, OUTPUT);

You can program the ATtiny85 using the Arduino IDE.  The basic steps are presented here.  There is a link to an excellent video at the end of this section that explains the process of getting your environment setup in great detail.

If everything goes as planned, when you plug the ATtiny85 into the computer using a Micro USB cable, you will see the device recognized as Digispark Bootloader in the Windows Device Manager window.

If you are new to the ATtiny85, or have any issues with getting the programming environment up and running it is highly recommended that you watch this excellent video as it answers most of the questions that may come up:

One unique feature of programming the ATtiny85 module is that you do not select a COM port to communicate to it with.  Instead you follow these basic steps:

Our example here creates a simple temperature and humidity display.  The LCD display uses I2C communications and the DHT22 humidity/temperature sensor uses a library to communicate using one pin.

Some libraries that come with the Digistump download are standard libraries that have been modified to work with the ATtiny85, but still have the same name.  For example, our program is using the LiquidCrystal_I2C.h library which has been modified to work with the ATiny85.  If you are getting errors because the program is not finding the correct library to use, simply copy the  LiquidCrystal_I2C.h and LiquidCrystal_I2C.cpp files from the Digistump download location to the same folder as the ATtiny85 sketch.  The parenthesis around the library name in the program below tell the compiler to look in the current directory for the files.

Also connect a source of 5V power for the LCD and DH22.  In our setup here, we are using a 5V power supply to supply power to the LCD display, DH22 sensor and the ATtiny85 module.

<iframe style="height: 510px; width: 100%; margin: 10px 0 10px;" allowTransparency="true" src="https://codebender.cc/embed/example/TinyWireM/Tiny85_Temp_LCD_RTC" frameborder="0"></iframe>

After some googling, it became apparent that unlike LEDs, LCDs don’t like to have constant voltage applied over them, but instead need an AC source. They don’t draw current like LEDs, but instead work like capacitive planes, the segments with voltage difference between the segment and common cathode becoming visible. LCD segments get damaged if there is DC voltage for long periods of time, so the solution is to apply a square wave of about 100 Hz (some models like 30 Hz, others 200 Hz) to the common cathode and one in opposite phase to a segment to “light” it.

So if you use a MCU with 5V operating voltage to control the LCD, you first set the common cathode to 0V (ground) and a segment to 5V (VCC). After a while, you switch. This way, a segment experiences alternating voltages of +5V and -5V and does not get damaged. Finally, I found a great application note from Maxim that explained this really clearly and recommended 1k resistors for segments and none for the common cathode. I was good to go! Here’s a rough schematic:

Quick check with an oscilloscope shows that PD6 and PBx really toggle between same and opposing phase (here’s a moment when they are in opposing phase, “LCD on” – note that I’m using 1:10 probes here):

It was a nice hack, but using 50 pins of a microcontroller or alternatively something like 7 shift registers seemed an overkill. But it’s good to know how an LCD works in any case. Here’s the complete source file if you want to try it out (at your own risk of course :).