Attiny Usi Uart How To Implement I2C

Such modules exist but they are kind of expensive for the simeple thing they do.

Ref.

Lets see now how we can use that library to work with the BOSCH BMP180 atmospheric pressure sensor and a ATtiny85 Tinusaur boards.

This library is called USITWIX and will be presented in this blog post.

Its an incredibly useful technology for us microcontroller hobbyists but can seem daunting for new users.

Attiny Usi Uart How To Implement I2C

This tutorial will solve that problem, first by reviewing what I2C is and how it works, then by going in-depth on how to implement I2C in Atmels ATTiny USI (Universal Serial Interface) hardware.

If youre reading this Instructable then youve probably heard of the I2C bus and may even have used it on a PIC or other microcontroller.

While conceptually very simple, and supported by hardware resources on the AVRs, software drivers are still necessary to use the I2C bus.

Atmel provides Application Notes (see the Resources later in this Instructable), but these are incomplete and dont show any examples beyond communicating with another AVR device.

The library is called USIUARTX and will be presented in another blog post.

The BMP180TINY library (Source code at ) uses it to communicate with an BMP180 pressure sensor.

It allows you to output text from the Tinusaur (ATtiny85 microcontroller or other similar), though USB-to-Serial or TTL converter (based on PL2303, CH340G or similar) and to the computer screen using COM port monitoring tool.

The problem is this: (1) those micro-controllers have too few IO ports; and (2) most of the programmers (ex.: USBasp ) do not offer that kind of communication between the micro-controller and the computer, i.e.

One particularly simple to use is the Hercules Setup utility by HW group it is just one EXE file that you run thats it.

So I used another function usint2decascii that I previously wrote for another project OWOWOD which code, in turn, I borrowed from a third project LCDDDD an LCD D irect D rawing D river for PCD8544 based displays such as Nokia 3310 LCD.

The weird LCDDDD name comes from the fact that it outputs the data directly to the LCD instead of storing it into a buffer first and then periodically outputting it to the LCD this is unlike most of the popular LCD drivers.

Since the largest number is 65535 that is 0xFFFF in hex, 51 bytes are needed for that buffer.

Both numbers are right-aligned and left-padded with up to 4 spaces.

Typical uses of buzzers and beepers include alarm devices, timers and confirmation of user input such as a mouse click or keystroke.

When voltage is applied to it its membrane moves up (or down, depending on the particular device) and respectively when there is no voltage the membrane goes back to its normal position.

Applying constantly changing voltage will generate audio waves perceived by us as a sound.

That means the period of the signal will be 2 x 500 uS 1000 uS (or 0.0001 sec.) and then the frequency is 1 0.0001 S 10000.

That means the sound will have frequency of 10 KHz.

According to the delayloop2(int) documentation it produces 4 empty CPU cycles per iteration in other words with parameter 100 it will produce delay of 400 CPU cycles.