[Introduction]

In a normal design the most extended method to flash an AVR microcontroller is by routing MCU ICSP pins to a dedicated ICSP connector. An alternative way when you're still developing the product is to use a bootloader.

Bootloader is the option we choosed with Memtype during development phase but, the space occupied by the bootloader is valuable space we can use for credential storage, so we decided to remove the bootloader for end user units (about 2KB space freed).

[Bootloader]

Our decision for attiny85 bootloader is Micronucleus, you can find more information in their github repository: Micronucleus Attiny85 Bootloader

[Memtype First programming method]

The first method that came to our minds were those mini grabbers test clips you can see on the image below, as they are used in a lot of projects. But we realized that grabbing six clips in such a narrow space was not only time consumming, but also a source of problems as connections to attiny pins were too lose.

[Memtype Final solution adopted]

We improved our programming method by using a special test clip for SOIC ICs that fits perfectly on the attiny, this saved us time and headaches as now with one movement we had all the pins attached with a perfect connection.

This kind of test clips can be bought for less than 5$ on ebay: SOIC8 test clip

For those wanting to know the ICSP pin description for the attiny85 you can check the image below:

Regards,

Noel & Miguel.