By IKTech July 15, 2017

Atmel’s AVR microcontroller chips are in-framework programmable (ISP), i.e. these can be modified straightforwardly in the objective circuit.

A unique developer programming is utilized to download the program from the PC into the AVR’s blaze memory. Atmel offers a product bundle called the Atmel AVR ISP that permits programming of the AVR microcontrollers in the circuit utilizing a basic dongle. A dongle is only a connector link that interfaces the PC’s parallel port with the ISP pins of the AVR chip for programming.

For programming, the four lines daptor (dongle) are:

1. MOSI (Master Out, Slave In): Data being transmitted to the AVR being customized is sent on this stick

2. MISO (Master In, Slave Out): Data gotten from the AVR being customized is sent on this stick

3. SCK (Shift Clock): Serial clock produced by the software engineer from the PC.

4. RST (Reset): Reset (low heartbeat) produced by the program. The AVR is modified while in reset state.

Here’s a dongle circuit for in-framework programming of Atmel’s AVR chip AT90S8515 utilizing such programming bundles as Atmel ISP 2.65 and PonyProg2000. In spite of the fact that not precisely the same, a comparable dongle circuit can be found at the Website ‘’

The PC’s parallel-port pins 4 and 5 drive cushion IC 74LS244 by empowering its pins 19 and 1, separately. A low heartbeat on these pins will permit the death of the serial clock and information amid programming. MOSI, LED, SCK and RST yields are supported from the parallel port’s pins 7, 8, 6 and 9, separately. The MISO contribution from the AVR is bolstered into stick 10 of the parallel port.

IC 74LS244 (IC1) goes about as a cushion and in addition an isolator circuit when the AVR is not in programming mode. Out of gear mode, every one of the yields are tristated so as not to influence the operation of the objective framework.

At the point when the AVR’s ISP mode is chosen, the lower half of IC 74LS244 is empowered, pulling the objective framework’s Reset line low. Once the objective framework is in Reset mode, the SCK, MISO and MOSI lines are never again stacked by the fringe hardware, assuming any, on the objective framework. Presently, it is protected to empower the upper portion of 74LS244, driving the MOSI, LED and SCK lines of the dongle. The RST stick turns out to be high after the AVR is customized. Shining of LED2 shows that the AVR is in programming mode.

There are two standard connectors for in-framework programming of Atmel AVR microcontroller. One is the 10-stick header (double in-line (DIL) connector)) utilized on the Atmel STK packs. The other is a 6-stick header (DIL connector) utilized as a part of Atmel ISPs. The two circle back associations, stick 2-to-stick 12 and stick 3-to-stick 11 of the parallel port, are utilized to distinguish the dongle. With just stick 2-to-stick 12 connect, the dongle is called STK300 or AVR ISP dongle. With just stick 3-to-stick 11 interface, the dongle is called STK200 or old Kanda ISP dongle. With the two connections set up, the dongle is distinguished as an esteem included pack dongle.

Here, we’ve utilized a 8-stick single-in-line (SIL) connector and an extra 6-stick SIL connector for the Atmel programer circuit. With the cushion and the 40-stick ZIF attachment in this circuit, it can be utilized as an independent developer. The 6-stick SIL male connector is utilized for association between the dongle and the AVR on the objective board. In this manner, another 6-line link of around 30cm length is required for associating this ISP connector (dongle) to the objective circuit.

On the off chance that the AVR is not on the objective circuit, you can embed the AVR into the ZIF attachment and program it. Controlled 5V DC is required for the AVR and the related dongle circuit, whose terminals are additionally given in connector CON4. LED1 is utilized as the power marker for the circuit.

Leave a Reply

Your email address will not be published.