AVRISP MKII for clock calibration

[fernandv]

I want to calibrate the clock of an ATTiny13. A few thousand of such devices are already in the field, thousands will follow.
In the past calibration was done with the  Atmel AVRISP2, which is now discontinued.

The procedure followed is described in AVR053 and uses the STK500.exe tool.

I tried in vain to make it work, how do I proceed to do this with your product?

This question was already asked in your forum by VAD on February 13, 2013.

Thanks for helping out.

[maredsous10]

On ATTiny devices, I calibrate using a custom python script, attprogram.exe, and an oscilloscope.

The scheme I have requires technician or manufacturing personnel to make measurements and feed these to the script.

Each device gets a specific calibration value stored in program memory.  I currently store it at 0x1ff.

Procedure
1.  Run the script which pulls in the program hex file and the sub-frequency rate we are looking for from the command line
2.  The script erases the devices then programs/verifies the device with a calibration set on the low side
3.  Technician is prompted to type in the measured frequency.
4.  The script erases the devices then programs/verifies the device with a calibration set on the high side
5.  Technician is prompted to type in the measured frequency.
6.  The script uses the low and high side measurements to compute a calibration value.
7.  The script erases the devices then programs/verifies the device with the computed calibration value.
6.  The technician can then the tweak the calibration value up or down to refine the calibration.