Vermes
Advanced Member level 4
The main assumption of this project was to create as small as possible USBasp programmer. The board was designed in Eagle and digested in B327. Scheme of the programmer is identical to those from fischl, except that a RESET button was added and the order of pins in IDC connector was changed. The whole is closed in a popular housing KM-3.
Specification:
The device is equipped with a voltage filter (capacitors 100u and 100n). The dimensions of the programmer are: 5x3x2cm. There are two diodes: ready and busy. The connector used is USBmini-B. Next to the USB there is the RESET button. At the input of leg/RST there is a capacitor 10n and resistor 10k which pulls up to VCC. The system also has three configuration jumpers:
- giving the voltage from USB to ISP connector
- selecting the transmission speed
- selfprogramming
PCB:
When you use too small guides while making the PCB, you have to use wires as in the pictures, because the guides are detached every time the IDC connector moves. Wires between the USB connector and the button are used because poor toner during etching caused the paths glued off.
Elements used:
- Atmega8
- capacitors
- resistors
- Zener diodes
- LEDs
- IDC connectors
- HEADERS
- mini USB-B
- button
- quartz
- housing
The load for the processor can be found at LINK.
Pictures:
Link to original thread (useful attachment) – Programator USBasp by Narasta