So I released new board revisions over the past few days, I have done my best initial check on these but I have not yet ordered them to build up. Even if I had ordered them I would still correct any mistakes in new revisions so the files might as well be public.

I am also working on a differential version of the PCM4202 ADC board, I did have a revision 1.0 design but I am not happy with it and so decided to rework this. It should be a more versatile solution than the single ended version and have a better PCB layout.

I also came across Orange Pi SBCs which look very neat with the AllWinner H3 SoC onboard all of them. Early 2015 I had started designing an ADAU1452 Raspberry Pi hat type board, unfinished designs still available at github.com/pwzj/ohdsp.

I stopped working on this as the Pi only support I2S in stereo with no TDM, limiting what I wanted to do with it. The AllWinner H3 SoC datasheet specifies support for all the normal I2S/left and right justified/TDM modes on the audio data lines and so this may work for my original idea. I am very tempted to either spin an ADAU1452 DSP board to interface with this, or make an adapter board to hook into my current DSP design. This all depends on software/driver support for TDM mode, and I need to do a lot more research.

So I finished revision 2.0 DSP board layout, I need to run some final checks over this and make sure it is ok. A tweaked power supply layout with solid ground planes is complete except for some track/polygon overlap errors; not sure why they are errors as the PCB looks fine.

I got close to finishing some changes on the ADAU1966 DAC board and then ripped up the jumper/spi header/power supply sections as I am just not happy with the layout. I also thought switching to a 4 layer board would help. As I am aiming to use this as the main analogue output source for several projects the extra cost of a 4 layer board is justified to me.

I also invested in a new toy:

It's a Siglent SDS1202X - initially I ordered the SDS1102X but changed the order. As it is only 1GSa/s shared between 2 channels the full 200MHz bandwidth is limited when using both channels at once. As I would like to be able to probe up to 50MHz square waves the extra bandwidth is useful even if it is only really accessible with only 1 channel on.

It's a nice piece of kit, I have only played with it a couple of times so far. The features it has are unbelievable for the price, even some of the megabuck scopes I have played with have less features than this by default! I had been hoping to redeem the free decode option currently advertised on the Siglent website but heard nothing from my email yet. You do get decode free for 30 uses anyway, although I am not yet sure if things like SPI decode are any use on the 2 channel oscilloscope, unless the SPI clock can be used on the trigger input.