AVR fuzz fix. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

AVR fuzz fix. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Microcontrollers

Comments on the article

The salvation of the controllers is the work of the controllers themselves. This circuit to fix incorrectly wired ATTINY2313 fuses (although other AVRs can probably be reprogrammed, they have similar commands) uses the parallel programming mode. The MK restores the factory settings, and most importantly the SPIEN bit, the internal generator turns on, and you can use the serial programmer again, I use USB on atmega8. Its speed must be reduced, i.e. close pin 14 ( PB0 ) through a 300 ohm resistor to the case. The increased speed is apparently intended for programming MKs inserted into the sockets located on the programmer board. I had an ATTINY2313 on a breadboard connected by wires (about 20 cm) with a programmer, and at increased speed there were read and FLASH errors and signatures and fuzzes. The erased FLASH was read - partly FFFF, partly 0000, partly some random values. It was also such that after the first programming MK generally ceased to be determined. As soon as the programmer switched to LOW mode, all errors disappeared, of course, the write and read time increased. The program was used - ChipBlasterAVR ver 1.12.

The circuit below corrects the fuzz. The frequency of the quartz does not really matter, maybe 1 MHz and 10 MHz, or an internal oscillator with or without frequency division. If only one AVR needs to be fixed, then it is soldered on top of D1, only some of the pins are bent and connected to resistors with thin wires. If there are several AVRs, then a socket for a 20-pin package is soldered on top (although the sockets are not very reliable). First, you may have to select the number of diodes to obtain a voltage of 12V on the collector of the current source KT361 (11,5 ...... 12,5), the collector current is approximately 10mA (you can select a resistor connected to the base). When using another MK instead of D2, you need to compare the datasheets (fuses of other AVRs are completely different and the SPIEN bit may be in a different category, then you will have to change some lines of the firmware), although there are errors in the reference data on ATTINY2313, the PAGE and BS2 input numbers are not correctly indicated . The program is also given (may be useful to someone), time delays are organized on program cycles.

First, when two supply voltages are applied simultaneously (from one power supply unit), the chip is erased, then the higher fuses are recorded further than the lower ones, the LED should blink three times (ti = 1ms at 8 MHz quartz, i.e., the RDY / BSY response signal comes three times ). The power must turn on at the same time (you need a PSU that gives out both + 5V and + 15V), then the MK makes a long delay, then 0 is set to pin. R, then +12V...etc.

If, after restoring the fuses, the generator is reprogrammed from internal to external quartz (using ChipBlasterAVR), then avr ceases to be detected (the signature will not be read) until the external quartz is soldered.

AVR fuzz fix

There are similar schematics in Greek serasidis.gr and German dl5neg.de on AVR AT90S1200, but there is no feedback from the RDY/BSY ( R/B ) output.

Download HEX firmware and program source

Author: jem9kip; Publication: cxem.net

See other articles Section Microcontrollers.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

Battery scooter 15.12.2001

American inventor Dean Kamen demonstrated to the public his invention, known as Ginger.

The device is a two-wheeled scooter powered by a battery. According to the descriptions of people who have ventured to try a new vehicle, it is unusually stable, maneuverable and even provides the ability to go up and down stairs.

With minimal electricity consumption, a person of average build can drive it all day at a speed not exceeding 30 km / h, which is quite enough for modern cities clogged with transport. In order to make the scooter move in a certain direction, the rider only has to lean slightly in that direction.

Other interesting news:

▪ Gamers against COVID-19

▪ Stem cells have been trained to produce insulin

▪ 3,5mm battery for wearable electronics

▪ Gravitational waves could help predict tsunamis

▪ Rare metals from coal

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Voltage converters, rectifiers, inverters. Article selection

▪ article Steering wheels on threads. Tips for a modeler

▪ article Which software pirates have tried to sue other pirates for illegally using their brand? Detailed answer

▪ article Painting work. Standard instruction on labor protection