Gromov's programmer: appointment, description

For people who like to design radio electronic devices, sooner or later there is a need to use microcontrollers in their designs. The use of these devices opens up huge opportunities for the radio engineer. Microcontrollers produce only a few companies, the leaders are Microchip Technology, ATMEL, ARM Limited. A feature of such devices is the need for their firmware. That's why programmers are required. There are many types of these devices, you can buy branded, and you can do it yourself. If you chose the second option, it's best to use a ready and tested solution, such as Gromov's programmer. The device is quite simple, it can even be built by a novice.

COM (AVR) -Programmer Gromov

The COM programmer is easy to manufacture. If the alternative mode of the COM port of BitBang is applied, conversion of the RS232 interface of the COM port to SPI, which is necessary for programming, becomes unnecessary. It only remains to reconcile the signal levels in the COM port, from -12V, + 12V to 0V and + 5V. For this purpose, the programmer scheme for AVR-controllers is designed. The photo below shows Gromov's programmer.

For the first time this scheme was proposed by the author of the program AlgoritmBuilder Gennady Gromov and quickly gained popularity by its reliability and simplicity of execution.

In order to start assembling the device, we will need:

• Diodes KD510, KD522, 1N4148 or their analogs.
• Seven resistors with a nominal resistance of 1 kOhm, power does not matter.
• Loop - you can use an unnecessary computer IDE-loop. For more stable operation of the programmer circuit, it is necessary to alternate the signal wires with zero wire. So we can reduce the level of induced interference in the circuits, and also extend the programming wire. However, do not get carried away, the length of the loop should not exceed 50cm.
• Connector for connection to the programmable device, you can use the standard connectors (by the way, the microcontroller manufacturers recommend it as well), but you can use the BLS (female) connector, the same connectors in the computers on the motherboard are connected to the body buttons and LEDs And pins of type PLS ("dads"). The use of these connectors allows you to significantly simplify the device card, since the pins of the programmer are placed in close proximity to the legs of the microcontroller. Contacts SCK, MOSI, MISO microcontroller type AVR are located together, respectively, they should use a built-in connector. Separately connect the "ground" and "reset".

As you can see everything is very simple, this is what Gromov's programmer is valued for.

To run this device you need a program and a firmware firmware microcontroller.

The universal programmer Gromov is assembled on passive elements. It does not require separate power supply, and what is most interesting, because of the parasitic voltage arising in the circuit, microcontrollers can be programmed without connecting to a power source.

By the same principle, it is possible to assemble a usb programmer, but the scheme of such a device is somewhat more complicated.