Для людей, которые любят конструировать radio electronic devices, sooner or later there is a need to use microcontrollers in their developments. The use of these devices opens up tremendous opportunities for the radio engineer. Microcontrollers are produced by only a few firms, the leaders are Microchip Technology, ATMEL, ARM Limited. A feature of such devices is the need for their firmware. That's what programmers are for. There are many types of these devices, you can purchase a brand, and you can do it yourself. If you chose the second option, it is best to use a ready-made and proven solution, such as the Gromov programmer. The device is quite simple, even a novice can assemble it.
COM (AVR) -programmer Gromov
COM programmer is easy to manufacture.Provided that the alternative Bitbang COM-mode is used, it becomes unnecessary to convert the RS232 interface of the COM port to SPI, which is required for programming. It will only be necessary to coordinate the signal levels in the COM port, from -12V, + 12V to 0V and + 5V. The programmer circuit for AVR controllers is intended for this purpose. The photo below shows the Gromov programmer.
This scheme was first proposed by the author of the AlgoritmBuilder program, Gennady Gromov, and quickly gained popularity with its reliability and ease of execution.
In order to proceed with the assembly of the device, we need:
- Diodes KD510, KD522, 1N4148 or their analogues.
- Seven resistors with a nominal resistance of 1 kΩ, power does not matter.
- Loop - you can use unnecessarycomputer IDE loop. For a more stable operation of the programmer circuit, it is necessary to alternate the signal wires with the neutral wire. So we can reduce the level of induced interference in the circuits, as well as lengthen the programming wire. However, you should not get carried away, the length of the loop should not exceed 50cm.
- Connector for connecting to programmablethe device, you can use the standard connectors (by the way, microcontroller manufacturers recommend it), and you can use the BLS type connector (“mother”), the same connectors in the computers on the motherboard are connected to the case buttons and LEDs and PLS pins ( "Dad"). The use of these connectors can significantly simplify the device board, 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, for them, you 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 appreciates.
For the operation of this device, the program and test firmware of the microcontroller are required
Gromov's universal programmer is going topassive elements. It does not require a separate power supply, and what is most interesting, because of the parasitic voltage arising in the circuit, the microcontrollers can be programmed without connecting to the power supply.
The same principle can be assembled and usb programmer, but the scheme of such a device is somewhat more complicated.
