attiny85 lcd display for sale

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,:

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.

In an earlier article “Two wire interface for LCD with shift register“, I discussed  how to make a two wire interface for an LCD and use that on the Arduino.

Obviously if there is any chip  in the AVR arsenal that would benefit from only having two wires necessary for  an LCD, it is the Attiny (85/45/25). It is very well possible to use this interface with an Attiny as well.

There are various cores available for the Attiny85 and I have tried a couple. Some will not work with this (a hoist of errors regarding the ‘print.h’ file), but the Attiny core from David Mellis works for me.

I found out that I had some trouble using the I2C port on an Attiny85 if I also used this 2 wire LCD, I am not sure yet where the problem is, maybe some shared timers or maybe  the HC164 needs serious decoupling. Anyway, if you are using I2C on an Attiny, you might as well use an I2C LCD as well.

My first part of the assignment involved finishing the ATTiny85 programming jig, since I hadn’t got too far in class—only one pin was soldered. While the process felt somewhat tedious, it went smoothly. I checked for shorts between any two pins using a potentiometer and found none. I followed the programming tutorial on the class website in order to burn the ATTiny’s bootloader and upload my own sketch. Surprisingly, everything worked from the first attempt. I ended up adding an LED to the jig and connecting it to the ATTiny’s digital pin 3, as a way of improving the jig’s functionality to testing, in addition to programming.

For the project application, I decided to use a component I’d never worked with before. During last semester’s garage sale, I purchased a 16x2 LCD screen and never had the chance to use it. I will say from the get go that my attempt failed :). Here is why.

Very briefly, the LCD screen has 16 pins. 8 of them (D0 to D7) are used for sending over bytes of information that need to be displayed on the screen, as well as commands (move cursor, clear screen etc.). Two of them are power and ground (VSS, VDD). Two of them are power and ground for the backlight LED (A and K.) Three of them are used in order to set different communication modes for the 8 data pins (RS, RW and E). And last, but not least, one pin (V0) needs to be hooked to a potentiometer and it controls the screen’s contrast.

16 is a lot of pins, since our ATTiny only has 8 pins total, 5* of which can be used for data. (potentially 6 if we consider the RESET pin, more on that in a bit.) The good news is that we can operate the LCD screen by using only 6 pins: RS and E for setting the communication modes, and 4 of the 8 data pins. The LiquidCrystal library implements an 8-bit mode and a 4-bit mode, meaning that the same information can be sent to the screen using only pins D4 through D7. The bad news is that the ATTiny85 only has 5 digital pins available by default.

The result of this exercise is that the LED screen works, but displays gibberish, since I had to sacrifice one of the 4 data pins. I ended up plugging it into power, so it’s consistently on HIGH.

Start the Arduino IDE and copy/paste this program into it. Upload the program to the Attiny85./*********************************************************************

The line of code that says "lcd.setBacklight(7);" is for an RGB LCD. You can use the numbers 1 - 7 to set the backilght to different colors. If you are using a monochrome screen use "lcd.setBacklight(ON);".

The Nokia 5110 LCD screen is a nice little LCD sold by both Sparkfun and Adafruit.  I needed to work with one for my wireless weather station and wanted to use my logo instead of the Adafruit logo which comes in their library.  So I wrote a processing program to make creating images easier.

I’m working on a project where I need several sensors that communicate back to a central processor.  Since I’ll have several of these sensors I need them to be cheap and the ATtiny85 jumped to mind.  The only problem is that I’ve never used i2c with the ATtiny series before.  I read dozens of “tutorials” about it from around the web and couldn’t find a nice simple example.  This is my solution.

I previously covered a method of programming the ATtiny85 using an Arduino Duemilanove.  However, my Duemilanove board isn’t working at the moment and I need to work on a project so I decided to program it with an Atmel AVRISP mkII programmer.  Here are the simple steps, mostly so that I don’t have to lookup the pinouts online next time I need to do this. Continue reading “Programming an ATtiny85 with the AVRISP mkII” →

One of the many projects I’m working on requires rotary encoders communicating with a drawing program running on a computer.  As always, I’d prefer to do this as cheaply as possible and since I’m working with the ATtiny a lot lately, I thought I’d try it on that.  Continue reading “Rotary Encoder with the ATtiny85” →

One of the first things I wanted to work on after figuring out how to program the ATtiny85 was to get serial communication working.  Turns out this is incredibly simple.  You just have to use the standard software serial library and define the rx and tx pins.  Continue reading “Software Serial on the ATtiny85” →

As the dynamic drive does not powered every segment in continuous (and should use less current), and need less pins, I bough the following display (working at 3.3V) :

I thought that I would be able to drive them with a barebone ATMega328p, but after few researches after receiving the display, I seemed too challenging (again !).

It seemed to work with a driver similar to an HT1621 (datasheet). With SPI, you write some values in the RAM of HT1621, and the driver will use them to turn on / off the segments of the display.

It has enough pins to drive my LCD display and receive a button pressed event. Moreover, at has some interrupts to be awaken when the button is pressed.

To use less current as possible, I choose to use the power-down mode. It has some restriction (external interrupts, internal clock), but the ATtiny85 only consumes 0.1V @ 1.8V & 1Mhz.

This Tiny AVR Programmer makes programming the ATtiny85 chip for my project so much easier. I love it! However, I recently ran into a problem. I just tried loading some new sketches using Arduino IDE v1.0.5 on a Win7 64-bit machine and I get a verification error. I have used this machine and software many times before without problems. IT appears from my searches that this indicates some kind of communication breakdown between the programmer and the computer. The onboard LED does show communication activity. I have tried two different chips. I have tried burning bootloader in case fuses had been changed. I tried reloading the drivers and core files.

C:\Program Files (x86)\Arduino\hardware/tools/avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -pattiny85 -cusbtiny -Uflash:w:C:\Users\Krist\AppData\Local\Temp\build282759822894877516.tmp\ATtiny85_Blink.cpp.hex:i

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.

Development boards are essential in embedded electronics and here we present the small ATtiny85 development board. The ATtiny85 is a compact Development Board from the Arduino community. It is based on the 8-pin ATTiny85 ATMEL Microcontroller and has 6 Digital pins, out of which 4 pins are ADC compatible. It also has 3 PWM outputs and supports SPI, I2C and USART communication. The Flash memory size is about 8K.