Member #32186

Member Since: February 5, 2008

Country: United States

  • It says "it can operate down to 1.8V with external pull-ups...". However pin 3 (VCCIO) is connected to 3.3V. Wouldn't I have to supply an external 1.8V to this pin after cutting the trace to get it to work at 1.8V?

  • Nice to see something old-school with no microcontrollers for a change!

    I really love the layout. I've built a couple of tube amps based on Bruce Perens' "OddWatt" ultralinear design and been quite pleased with the results. However, I used a very conventional layout with tubes and trannys on top and wiring on the bottom. I really like the idea of exposing the wiring, at least for a "shop" system. I may try your approach next time with the perforated plates to mount the tubes.

    It seems I can't embed images here, so no photos :( Or maybe there is a trick to doing this?

  • Adding a 10uF to GND on the reset pin fixes the problem. This seems like a bit of a band-aid though, since the SAMD21 includes a fairly sophisticated power-on reset of it's own. I'm guessing there is something a bit funny going on in the startup code in the bootloader. Will look into it later when we attempt to customize it.

  • Love the board! We're using a bunch of them in a project for a lab here. We'd like to customize the bootloader as we have the boards on a shared serial bus and would like to be able to add some sort of addressing scheme.

    I'd prefer not to buy IAR tools. I notice the stock Arduino Zero bootloader can be built with gcc/make. Can the customized sparkfun one be built successfully with open-source tools? Or, is there a list of patches against the Arduino Zero one?

    We can sort this all out ourselves given time (and eager students) but if you guys have any suggestions it would be great.

  • The power-up reset doesn't seem to work. Is this expected? If we download a simple blinky light sketch it runs as expected if the USB cable is connected. If we power the board using 5V on VIN the sketch doesn't start unless the reset button is pressed.

  • I'm thinking of making this into an indoor/outdoor thermometer. Seems like a rather trivial task, since there are two spare ADC-capable pins. Anyone else tried this?

No public wish lists :(