[sdiy] Elektron Digitakt teardown

[rsdio at audiobanshee.com]

Interesting stuff, particularly the enhanced analog isolation.

Coldfire is 68000 from Freescale's Motorola heritage, right? … or is that only some of the Coldfire versions?

Putting aside for the moment that NXP purchased Freescale, what makes the Coldfire more like the ST Micro ARM chips than other ARM chips that other vendors are putting out?

Brian


On Jul 9, 2017, at 1:44 AM, Julian Schmidt <elfenjunge at gmx.net> wrote:
> found in the mutable forums, some pics and comments of the digitakt guts:
> https://www.flickr.com/photos/128743207@N08/sets/72157683648770700
> 
> "Compared to the "Analog" series devices from Elektron, there are a couple of changes.
> 	• The new "encoders" are actually potentiometers (probably sin/cos). That's very clever.
> 	• The "Analog"-series devices had a USB isolation to avoid having a ground loop when the device is connected to a computer         and an audio interface. The USB isolation chip was removed. Instead, there is now an isolation between the analog side and the digital side of the circuits. The power rails and grounds for the analog and digital sides are entirely isolated. That way, ground loops are still prevented, but in addition digital noise is kept away from the analog circuity much better.
> 	• The magnetic NVRAM that was used in the "Analog"-series devices was removed (probably too expensive and too small - the largest available on the market is currently 16Mbit). Instead, they use a 1Gbit DDR2 SDRAM powered from a Supercap. So, effectively you get the "persistent" memory (no loss of data when power-cycling, even without saving your project) but it porbably won't last 20 years like the magnetic NVRAM
> 	• The new switches are computer keyboard switches from Kailh - apparently that is a "Cherry MX" clone.
> 	• The type of OLED display is unfortunately not visible without desoldering it from the pcb.
> 	• They are still using a coldfire processor. To my understanding, that is pretty comparable to the higher STM32F7 devices (maybe a slightly faster) but interestingly the SRAM on those is only 64kB."
>