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free-pdk / easy-pdk-programmer-hardware

Easy PDK programmer for PADAUK microcontroller. EDA, schematic, gerber, bom, housing stl, firmware
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On-board programming with easy PDK Programmer: Possible? #24

Open ragnarrhomb opened 3 years ago

ragnarrhomb commented 3 years ago

In the PFS-datasheet section 9.2.8 they have this example (when writing with their tool): Capture

But the Easy PDK programmer does also have lines to PA0, PA4 and PA7. Is that necessary?

JustinOng commented 2 years ago

According to this, PA4 is used for calibration of IHRC.

ragnarrhomb commented 2 years ago

Ahh! Thanks for the catch! Do you know about "the limit" of usage of this pin to other things "in circuit" ?

JustinOng commented 2 years ago

This is pure speculation on my end: so your as your circuit does not excessively load the pin, you should be alright.

Of course, this comes with a whole long list of caveats - for example, in my application, I have PA4 connected to a MOSFET controlling a small vibration motor. Trying to program and calibrate a PFS172 while the motor is connected results in failure, which I believe is caused by the power rail browning out.

I would strongly suggest that you test your intended circuit to confirm for yourself whether it'll work in your application.