Making a tiny UPDI-HV programmer for microcontrollers #ATtiny #UDPI @technoblogy @MicrochipMakes

Technoblogy presents a simple High-Voltage UPDI programmer, for programming 0-series, 1-series, and 2-series ATtiny chips to allow you to configure the UPDI pin as a extra general I/O pin. For simplicity it is designed to work with an existing USB to Serial board, and an external 12V source.

The ATtiny 0-series, 1-series, and 2-series chips allow you to get an extra I/O pin by reprogramming the UPDI pin as a general I/O pin. However, the downside is that you can’t subsequently use a regular UPDI programmer to reprogram the chip.

Microchip provide a reset mechanism, which involves applying a short pulse to the UPDI pin before programming it. Although the method is called ‘High-Voltage Activation’, the pulse is actually only 12V, slightly higher than the normal 3.3V or 5V voltage level.

This programmer extends a standard SerialUPDI programmer with extra circuitry to automatically apply the 12V HV pulse, and program an ATtiny chip even when the UPDI pin has been reprogrammed to another function.

See more about the design in the post here.


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