Hello Andrew, While I appreciate you wanting to help out, I'd like to share my opinion.
Assuming a maximum of 192k available RAM, this equals 98304 16-bit samples. At 1 MHz, the this buffer would be filled in 0.098304 seconds, which is almost 100ms. Using 8-bit samples, this would double to almost 200ms. At 4 MHz, those numbers drop to 25ms and 50ms, respectively - and this is just for a single channel. With a Cypress FX2 and an ADC, you can achieve a 24 MHz sample rate with virtually unlimited duration. The FX2 can be had for $10 and the ADC for about the same, so in my opinion, it's not really worth putting in so much effort to making a device that costs half of this but has significantly lower specs. I'm not trying to stop you at all, just want to point out the obvious alternative. -Soeren On Sun, 2018-06-03 at 23:31 +0800, andrew goh via sigrok-devel wrote: > hi all, > > i'm a newbie, novice to sigrok, just hope to get some pointers. > there are many stm32 based development boards (e.g. the discovery > and > nucleo series from ST itself), and there are many others which can > be > purchased on ebay etc for a rather low cost. e.g. if one search for > stm32f103 on ebay one could come across boards like blue pill or > maple > mini that goes as low as $2. these devices based on arm cortex-m3 > runs > at 72mhz has 2 adc which could push an envelop of about 2msps > sampling > speeds and gpios in the 10s of mhz. then the higher end devices e.g. > m4 > stm32f407 runs at 168mhz has adcs that run up to 7msps and gpio > sampling > speeds faster than the m3 series and the larger ve-zg devices has > decent > amount of ram e.g. 64k-192k sram. and stm32 f3 series has adc that > can > push 18msps quad interleaved. hence despite a only an on chip-full > speed usb 2.0, they can work as oscilloscopes or logic analyzers by > storing the adc samples to ram and later transmit that over usb. it > won't be those 100msps speeds but may be still useful for the lower > mhz > analysis > > if i want to turn these boards to interface with sigrok / pulseview > etc. > where do i start looking for info? > are there any 'standard' sigrok protocols for oscilloscopes and > logic > analyzers where i can just build the firmware on the stm32 soc so > that > they'd 'just work' without changes at sigrok end? > > thanks in advance. > > andrew > > > > ------------------------------------------------------------------- > ----------- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > sigrok-devel mailing list > sigrok-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sigrok-devel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ sigrok-devel mailing list sigrok-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sigrok-devel
