Tag Archives: AVR

Externally clocking (and overclocking) AVR MCUs

KXO44Mhz

by nerdralph.blogspot.ca:

People familiar with AVR boards such as Arduinos likely know most AVR MCUs can be clocked from an external crystal connected to 2 of the pins. When the AVR does not need to run at a precise clock frequency, it is also common to clock them from the internal 8Mhz oscillator. Before CPUs were made with internal oscillators or inverting amplifiers for external crystals, they were clocked by an external circuit. Although you won’t see many AVR projects doing this, every AVR I have used supports an external clock option.

Externally clocking (and overclocking) AVR MCUs – [Link]

ATMEGA16/32 DEVELOPMENT BOARD

C032_1

ATmega16/32 Development Board provides a very simple and cost effective platform for prototyping solution.  The compact design provides connection to all the pins of the microcontroller for the user.

  • Prototyping solution available for 40-pin ATmega series AVR microcontroller from ATMEL
  • All the four ports available to the user via standard 10 pin box header connector with supply of 5 VDC for interfacing circuits
  • Onboard reset switch for easy reset of the microcontroller

ATMEGA16/32 DEVELOPMENT BOARD – [Link]

Read multiple switches using ADC

DI5495f3

by Les Hughson @ edn.com:

The ATMega168 is a great general purpose 8-bit AVR microcontroller from Atmel. It has 23 GPIO pins, but sometimes (as I have found) you can run out of I/O pins as your design grows. This happened to me recently when, of the 23 GPIO pins available, 2 were taken up by an external ceramic resonator, 1 for the reset line, 3 for serial coms, 14 for the LCD, and 3 for RGB LED control. This used all 23 GPIO pins, with none left for the four buttons I needed. What to do? This Design Idea has the solution.

A close look at the ATMega168 data sheet revealed that the I/O pins available on the 28-pin DIP package and on the 32-pin TQFP package are not all the same. On the TQFP package, there are an additional pair of VCC & GND pins and an additional two ADC input pins on top of the advertised 23 GPIOs. So if I could read my 4 buttons with these extra ADC inputs, all would be OK and the design would be saved.

Read multiple switches using ADC – [Link]

DAN64 – an AVR based 8-bit microcomputer

tv-out

by Juan J. Martínez:

This is my first serious attempt to learn electronics. DAN64 is my first project and it has been a discovery process during 3 months of my free time. I had to learn a lot of things I didn’t know much about, from basic electronics to the details of the AVRs -and specifically the ATmega328-, and a whole world of things in between such as signalling, protocols, interfaces, modulation and demodulation, SDKs, EDA software, prototyping, PCB fabrication, etc.

I’m certain that in this project I’m doing many stupid things and I’m sure my approach to solving some of the problems is not the best, but in my discharge I can only say: it works! (to some extent at least).

I got lots of gotcha! moments, ups and downs where I though I couldn’t finish the project because perhaps what I was trying to achieve was just impossible.

So this is not about perfection but about good enough for me and about the learning process and having fun.

DAN64 – an AVR based 8-bit microcomputer – [Link]

Zero Tiny BLE – low cost and low powered embeddable board

tinybt

The Zero Tiny BLE is a small low cost and low powered embeddable board with an AVR ATTiny85 microcontroller and a Bluetooth 4.0 (Bluetooth Low Energy or BLE) radio.
AVR ATTiny85 microcontroller running at 8MHz internal clock and 3.3V. ATTiny85 Datasheet.

HM-10 Bluetooth 4.0 Low Energy module. HM-10 Datasheet.
Powered by single cell 3.7V Lithium Polymer battery (LiPo) or USB B mini port.
LiPo battery recharge capabilities via the USB B mini port.
Standard UART communication over Bluetooth 4.0.
Easy prototyping via breadboard.
Use either Arduino or AVR-GCC development environments.
Small form factor of 20mm x 47mm (0.79” x 1.85”)
You can purchase a complete board at zeroengineering.io
You can order unpopulated boards from OSH Park

Zero Tiny BLE – low cost and low powered embeddable board – [Link]

DIY AVR Development Board with Atmega128

atmega128_diy_development_board

by Radu Motisan @ pocketmagic.net:

For many of my previous projects I used AVR Microcontrollers extensively. I started with the Atmega8 and moved to superior AVR variants depending on the application complexity and requirements. Before designing any particular application, I usually do my research on a development board. It is a PCB featuring the target microcontroller and minimal support logic that usually covers a regulated power supply, pin headers to connect peripherals and/or a few LEDs used for basic debugging.

Such boards are available in many shapes and colours, from simple to complex and most of the times they are affordable (after all we’re talking about a minimal PCB with a microcontroller and a few, mostly passive, components).

DIY AVR Development Board with Atmega128 – [Link]

Piconomic FW Library 0.4.2 released

tera_term_cli

by Pieter @ piconomic.co.za:

If you can beg, steal or borrow an Atmel ISP programmer, then you can use the Arduino environment to develop on the Atmel AVR Atmega328P Scorpion Board. An Arduino on Scorpion Board guide, Optiboot bootloader and example sketches have been added.

If you own an Arduino Uno board, you can now try out the Piconomic FW Library risk free without abandoning the creature comforts of the Arduino environment. You can use the existing Optiboot bootloader to upload code. I have added a getting started guide for the Arduino Uno. There are examples, including a CLI (Command Line Interpreter) Application that creates a “Linux Shell”-like environment running on the Arduino Uno so that you can experiment with GPIO, ADC, I2C and SPI using only Terminal software (for example Tera Term)… it is really cool!

Piconomic FW Library 0.4.2 released – [Link]

Driving a DC motor using PWM with AVR ATmega

pwm_dc_motor_driver_atmega-600x575

Davide Gironi writes:

The PWM frequency have to be selected in the way that the switch frequency is much higher than the dynamics of the motor.
To avoid noise from the motor, the choosen PWM frequency is 20Khz. Which is a know to know frequency.
So, with this one, you can drive up to 4 motors independently controlling:
*speed
*direction
*slow start / stop
Setup parameters are contained in dcmotorpwm.h

This library was developed on Eclipse, built with avr-gcc on Atmega8 @ 8MHz.

[via]

Driving a DC motor using PWM with AVR ATmega – [Link]

Stand Alone AVR Programmer

IMG_0092

An autonomous AVR ISP programming device with SD-Card, Nokia display, ZIF socket and standard 6-pin ISP interface:

From project to project the number of hex files on our PC was increasing. Many people send us their virgin ATMegas to get them flashed. And last not least distributing PCB’s and pre-flahed chips via agile-hardware forced us to burn many, many AVRs. In principle this is a work an ape should do but reality was different. So we spend munch time in this boring job. To much time …

Thus it was just consequent to think about a device that would do the job for us. Here is the result, the SolderLab Easy Auto Programmer V1.0. An All-in-one AVR programmer with SD-card, Nokia Display, a ZIF-Socket and a 6-pin ISP interface. With this device the programming of an AVR is done in seconds including the setting of fuse bits (before AND after flashing), flashing the chip, verifying the flash. And all this without any connection to the PC and by pressing just one single button. You just have to put all your hex files into a folder called “hex” on a standard FAT32 formatted SD card, put the card into the programmer an supply it with some voltage (7-20V). That’s it the rest is done by the “ape”.

Stand Alone AVR Programmer – [Link]

Atmel ATmega328P Scorpion Board

 

piconomic_scorpion_board

This minimalistic board is packed with features and comes with an extensive ecosystem of documentation and firmware.

For the student (we are never too old) that wants to fast track his career as a professional firmware developer there is:

  • a detailed getting started guide
  • an Atmel AVR quick start guide, with tutorials and examples
  • Recommend best practices

For the developer that wants to improve his game there is:

  • A header to quickly connect different kinds of peripherals (GPIO, A/D, UART, SPI & I2C). Notice that each interface has it’s own +3V3 and GND pins to make wiring easier and also improves EMC.
  • A full-featured CLI application to experiment with the connected device and verify that it works, before committing to a single line of C code.
  • A firmware framework that lays the foundation so that you can quickly develop a new application.
  • A Temp&Pressure Logger and Analog voltage Logger application that demonstrates how you can quickly develop your own custom logging application using the onboard AT45D DataFlash.

Atmel ATmega328P Scorpion Board – [Link]