AVR Bootloader and Programmer

Posted on Feb 4, 2014

Atmel`s application note AVR109 describes a bootloader that uses the UART to communicate FLASH programming instructions. They also provide some sample code in C that allows the programming of FLASH, EEPROM, and lock bits. Note that the AVR109 bootloader does not support the programming of fuses which for safety cannot be changed by the bootloader.

Click here to download the full size of the above Circuit.

The communication protocol used is compatible with the AVRPROG programming software. After loading this into the bootloader section, the device can be configured so that on reset the program counter starts at the bootloader, and programmer software can program the FLASH memory. The ATMEL example bootloader program proposes the use of a port pin on the microcontroller to signal whether to execute the bootloader program or to jump directly to the application. This allows a user to set a jumper on the microcontroller card that pulls the pin low when programming of the FLASH is needed. The adaptation of this code described here, keeps it almost unchanged in the interests of compatibility. By disabling the port pin test and excluding the EEPROM programming section and the AVRPROG compatibility section, the code will fit neatly into a 1K block of the bootloader FLASH section on ATMega48/ATMega88/ATMega168 AVRs *. Disabling the port pin test means that on reset the microcontroller always ends up in the bootloader program (if the appropriate fuse bit has been set), and must be explicitly sent out again with a bootloader exit command. For the moment this is acceptable as the device will normally operate while connected to a PC serial port. For standalone operation a pin will need to be made available to implement the port pin test, or the appropriate fuse bit programmed to start the device on reset at location 0. In the latter case...

Visit page

Leave Comment

characters left:

Related Circuits

Color sensor

Color sensor. Colour sensor is an interesting project for hobbyists. The cir- cuit can sense eight colours, i.e. blue, green and red (primary colours); magenta, yellow.

Dew sensor

Dew sensor. Dew (condensed moisture) ad- versely affects the normal per- formance of sensitive electronic devices. A low-cost circuit described here can be used to.

Audio Visual Ringer

Audio Visual Ringer. Many a times one needs an extra telephone ringer in an ad-joining room to know if there is an incoming call. For example, if the telephone is installed in.

Multipurpose Circuit for telephone

Multipurpose Circuit for telephone. This add-on device for telephones can be connected in parallel to the telephone instrument. The circuit provides audio-visual indication of on-hook,.

Off line Telephone tester

Off line Telephone tester. Here is a circuit of an off-line telephone tester which does not require any telephone line for testing a telephone instrument. The circuit is so simple that.

Telephone Headgear

Telephone Headgear. Acompact, inexpensive and low component count telecom head- set can be constructed using two readily available transistors and a few other electronic.

Telephone line based audio muting and light on circuit

Telephone line based audio muting and light on circuit. Very often when enjoying music or watching TV at high audio level, we may not be able to hear a telephone ring and thus miss an important...

Telephone Ringer using 556 dual timers

Telephone Ringer using 556 dual timers. Using modulated rectangular waves of different time periods, The circuit presented here produces ringing tones similar to those produced by a telephone. The.

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....

Create NOW your QR MENU for your Restaurant / Hotel / Bar / Caffe,

Comprehensive ordering/paying features. fully personalized to suit your Business.

Update Anytime! Easy and Simple!

Popular Circuits

RS-232/485 converter has automatic flow control

The circuit in Figure 1 is an RS-232/485 converter that uses the transmitted signal itself to...

Stereo-power-meter

The Stereo Power Meter is made up of two identical circuits and a power supply. Each circuit...

Electronic Horn

Electronic horn circuit diagram. When power line is switched on, a general/basic tone is produced...

USB Powered Stereo PC Multimedia Speaker

USB Powered, Stereo PC Multimedia Speaker Circuit Diagram. This circuit is powered by 5V DC...

7025 ECC803S 12AX7A Tube RIAA Phono Preamplifier Schematic

This two-stage audio preamplifier is intended for use with high-fidelity magnetic phonograph...

Amp Compensation

Adding negative feedback to an amplifier, especially a vacuum tube amp is not as easy as it may...

Three-terminal linear regulator expansion flow circuit diagram

Circuit is a very common three-terminal linear regulator expansion flow circuit, when we actually...