Saturday, September 26, 2009

fun with graphic LCDs!

Got this graphic LCD from MC Shop, the DX-160. Wedged it inside a bare-bones Hollow Earth with a basic UI to see the potential!

Maybe I'll build a simple synth/drone box with manually drawable waveforms too.

I'm also clocking the AVR chip a lot fastern ow, 20MHz. I could get it to update the screen a lot faster, but I don't want it to drain juice needed for other stuff.

Wednesday, September 9, 2009

Sunday, September 6, 2009

potentially new Hollow Earth features..

I'm trying to squeeze the most out of this design. I've had a few feature requests and a lot of them were tap-tempo. Harmony-Central user crxsh had a good idea about making the soft-stomp, the one used for recording of shapes, multi-function. Specifically, being able to toggle it between record, tap-tempo and bank select.

I'm gonna see how feasable this is. It won't be ready for the next few batches as I still have PCBs to use up. Testing and optimizations also take time. But hopefully I'll get those to work. A three-way toggle switch could be placed on the side of the box next to the soft-stomp with a label describing the three states.

Another issue the Hollow Earth seems to have is that expression-out doesn't work with every pedal with expression-in, only some of them! I never intended it to be a main feature, just as a fun extra, but it seems more people want to use it than I had previously thought. I'll try and put some effort into increasing the compatibility of exp-out.

For the geeks, an expression pedal is basically a potentiometer. Potentiometers have three lugs, one for the minimum range, the max range, and the wiper. The way the Hollow Earth outputs expression control is by controlling an LED-LDR combo (an electrically-controlled pot), which due to its nature is the equivalent of an only 2-lug pot. While this works with many pedals with an expression-in jack, it doesn't work with those expecting 3-full lugs. So far, this includes the Eventide Timefactor and EHX HOG. I'll do my best to fix this in a later revision.