This projects contains PCB of the simple UPDI programmer board, which converts TTL output of the USB UART dongle (base on chips like FTDI FT232, Silicon Labs CP210x, WCH CH330 etc) into UPDI with wide variety of pin configurations to connect programmed chip.
UPDI stands for Unified Program and Debug Interface, a proprietary programming and debugging interface
developed by Atmel and Microchip for certain microcontrollers, particularly the modern ATtiny, ATmega and AVR series chips.
TTL UART to UPDI conversion itself is based on very simple wiring with one Schottky diode (eg. BAT-41) and one 470 ohm resistor connecting TxD to RxD described over the internet.
UPDI High-Voltage Activation is not available in this simple programmer!
- (1) Angled female 5 pin header for direct connection to USB UART dongle, MAKE SURE pins order matches as some dongles have different order!
- (2) Male 5 pin header for connection to USB UART dongle using wires
- (3) Programmed chip VCC voltage selector (5V, 3V3 or nothing) - voltage source is USB dongle
- (4) DIL connector for zero force and other programmed chip adapters with selectable UPDI pin (5). Can be used to plug 8 and more pins (14, 20) packages, which have different UPDI pin location.
- (6) Dual row pin header do directly connect 8 pin clip
- (7) Dual row pin header do directly connect clip with more than 8 pins which has different location of the UPDI pin
- (8) Three pin header to connect programmed chip using wires
- (9) a bit of VCC filtering
All pins of all connectors are clearly marked. Unmarked pins are not connected.
UART-UPDI_gerber.zip- Gerber file for PCB fabricationUART-UPDI.dip- DipTrace PCB design fileplatformio_examples/- examples how to use it in PlatformIO projects with different programmer SW, eg. withpymcuprog.
© 2025 This work is openly licensed via CC BY-SA 4.0