Originally posted by scrungy_doolittle
View Post
Announcement
Collapse
No announcement yet.
DSP in commercial prospecting and treasure hunting metal detectors ... and GPZ 7000 speculation
Collapse
X
-
Originally posted by scrungy_doolittle View PostI think you are quite wrong. The STM32F405/7 for example, has a 2.2 megasample pipelined triple ADC at 12 bits. The pic24FJ128GC010 has a 10 Megasample ADC. Either of these are adequate. Using DMA to directly transfer the data, and running at 168 mhz, there is more than enough processing to do multiple filters and analysis.
Comment
-
I'm not sure if this is 100% relevant but check out the DSP audio software here:http://www.dspconcepts.com/sites/def...urnal_DSPC.pdf
Ask for a free download. It looks cool for audio manipulation so may add value for the hobbyist with analog front end with Dsp based discrimination features.
Comment
-
Originally posted by Achillion View PostWell, I would like to see a working example of adequately direct sampling and processing with this microcontroller and have sufficient sampling speed and resolution to give meaningful results.
Comment
-
If you contact them they will give you a download link for a full featured copy. They are trying a new business model which i think works on a royalty basis if you productize what you are working on. The STM32F discovery board is a supported eval platform for it. It looked fun to try playing with so i'm set to go but have other things taking priority before I do...
I have a CTX - which I think has the depth needed but the processing can cause target misses and innaccurate identification. I think the future will bring better algorithms that perhaps sequentially ID/screen targets better.
Comment
-
Originally posted by Carl-NC View PostCortex M4 is very attractive for even high-end metal detectors, lots of parts are around 100uA/MHz core power.Originally posted by scrungy_doolittle View PostYeah. The GG group is using a STM32F411. The nucleo board is cheap. 10.33
I'll opine that the use of DSP seems relatively slow to adopt in this industry relative to say, audio consumer products. More than anything, I'll opine this is mostly an economics issue. The world-wide metal detector industry is but a minuscule fraction of the worldwide consumer audio industry. For every Carl and Bruce Candy, there are several orders of magnitude more equally sharp engineers with proportionally more $ behind them developing audio products (as just one consumer product example extensively utilizing DSP for many years).
Maybe the "STM32F???" in the GPZ 7000 is a STM32F4 (or higher end) using direct sampling?
Comment
-
Taktyk, the data available from the FCC mentions 3 devices used in this detector. How accurate or uptodate this information is, is anyones guess ?
The wireless audio reciever module uses the STM32F.
Also a Freescale IMX253, probably running some flavour of linux. For user interface, gps, etc.
And listed as well is a Microsemi M2S010-FGG484 fpga/SoC. How or what means are used to pipeline sensor data is unknown and would be speculation. Direct sampling, who knows ? ADC or comparator ?
https://apps.fcc.gov/oetcf/eas/repor...cc_id=Z4C-7000
Comment
-
Originally posted by greylourie View PostSample images of the audio rx module show a STM32F102C8T6 working in conjunction with a T.I CC2500 transceiver ic.
greylourie, where do you see these sample images ? I do not see them in the "internal images" link at the FCC site https://apps.fcc.gov/oetcf/eas/repor...cc_id=Z4C-7000
Comment
-
Hi wirelessguy
Originally posted by wirelessguy View Postgreylourie, where do you see these sample images ? I do not see them in the "internal images" link at the FCC site https://apps.fcc.gov/oetcf/eas/repor...cc_id=Z4C-7000
Comment
-
Originally posted by wirelessguy View PostI'll opine that the use of DSP seems relatively slow to adopt in this industry relative to say, audio consumer products. More than anything, I'll opine this is mostly an economics issue. The world-wide metal detector industry is but a minuscule fraction of the worldwide consumer audio industry.
Maybe the "STM32F???" in the GPZ 7000 is a STM32F4 (or higher end) using direct sampling?
Comment
Comment