From: Joerg Newsgroups: sci.electronics.design,comp.lang.forth Subject: Re: ball-hours Date: Thu, 16 Oct 2014 11:21:15 -0700 Lines: 79 Message-ID: References: <5sho3adpfhed897nb8jdju99897ouhrvrv@4ax.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: individual.net DKDUVnJe5X4qO90twKjh+QDxl4HWQNXgh9Y+BHL0Ms5nQ5Uhsm Cancel-Lock: sha1:lPuqHhNy3FVyneAsFFFPOzw4q8w= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070728 Thunderbird/2.0.0.6 Mnenhy/0.7.6.666 In-Reply-To: Path: csiph.com!usenet.pasdenom.info!dedibox.gegeweb.org!gegeweb.eu!nntpfeed.proxad.net!proxad.net!feeder1-2.proxad.net!feed.ac-versailles.fr!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Xref: csiph.com comp.lang.forth:33947 rickman wrote: > On 10/15/2014 7:12 PM, Joerg wrote: >> rickman wrote: >>> On 10/15/2014 8:36 AM, Joerg wrote: >>>> Problem is, there is no Forth community out here. The last die-hard >>>> Forth aficionado I personally met was about 30 years ago in Europe. >>> >>> I think you may be surprised. I've already heard from three programmers >>> from the few posts I've made in just three groups. Unless you want me >>> to send then directly to you, I am referring them to this thread. >>> >> >> One of them contacted me already. They are sort of local but not really >> local-local, like in the same village, down the road from here. We will >> have lots of situations such as "Hey, I got stuck with the test rig, can >> you come over real quick?" or "The relief valve over yonder blew a >> gasket, can you replace it?". > > So why aren't you working in the same lab? Then it can be like, > "Watson, come here. I want you". > Because as mentioned before if both are consultants it creates confidentiality issues. I have only one room (office plus lab) and another one mostly used for library and parts storage but not acoustically shielded. I often have to hop on GoTo or some other service to discuss another client's issue and then I must be alone. Sometimes for 1-2h. In contrast to contractors who work one longer assignment at a time I always have half a dozen or more active clients. > BTW, if you heard from Charley Shattuck, he is a prominent Forth > programmer. He is working with a startup that developed a Forth like > CPU with 144 processors with a peak rate of 700 MIPS each. This chip > includes 5 ADC and 5 DAC on chip with variable resolution (trade off > between speed and resolution, about 15 bits at 48 ksps). You might talk > to him about the GA144, it might suit your needs. It's main limitation > is each processor has little memory and the I/O is limited. But I don't > think you will run out of MIPS. lol > Yes, had an email exchange with Charley. 144 processors with 700MIPS each would probably require us to also build a nuclear power station :-) ... just kidding, I know it's green. > >>> ... Your other post seemed to be >>> talking about bitbanging the I2S port to the CODEC. How does that work >>> into the 100 MHz need? Bitbanging a serial port of any kind can be CPU >>> cycle intensive. >>> >> >> Yes, it is a major concern. We might need to hang an FPGA in there at >> least for TX, as a buffer, because essentially we are writing sine >> waves. Doesn't work on RX though, that's time-varying stuff. I hope I2S >> works for us, somehow. Got to find out. > > ??? > Well, to send out sine waves. No need to necessarily bother a processor with that. Or I use a DDS but that can cost in clock synchronicity. > What are the specs you need from the ADC? Do you have numbers and such? > I think you mentioned a low drift with temperature. The GA144 would > need to be compensated for temperature, but has lots of processing to do > that. :) > Five needed in total, 18bits or more, 48ksps, differential inputs, BW from DC to 15kHz, without phase jitter issues. DC-Offset can be handled via mux and SW-clamping as long as it won't jitter or drift around much. -- Regards, Joerg http://www.analogconsultants.com/