A FPGA Audio System in raspberrypi size and open source later. - Page 1
Forum section: electronics / general

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 03:54:06 am
content: Still some works are not done and need to fix. Will be opensourced after finishing these.

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 04:02:07 am
content: Welcome for any suggestions.Q&A:1. Why not DDR?A: because you need to pay for those analog things if you flows ASICs.(only SRAMs, standard cells, normal IOs and PLLs.) This FPGA is ready for validations before making ASICs.2.

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 04:06:47 am
content: Right up corner is for Bluetooth module, nRF5340 + CSR8811, support both Bluetooth classic and LE Audio(espressif doesn't support LE audio, and dual band bluetooth.).It takes much money(about $10 for 1 pcs), and i am sure I will populate only once and never again :'(

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 04:10:20 am
content: Old version, those mistakes have been fixed in the new version.

author: xvr
author_rank: Frequent Contributor
timestamp: April 11, 2024, 12:15:30 pm
content: Seems to me it will be quite costly for DIY niche

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 01:26:54 pm
content: reasons? for example6 layers at JLCPCB i cost about $42 and get about 7 pics.The XC7K70T-FBG484 cost me $22, the biggest part of course.The most expensive(for me) part for me is MAX9850 from ADI(Analog Inc. 's(include Maxim) parts are always of high performance and very expensive), about $3.the FT2232H from FTDI.and the 256Mbits HyperRAM.Si5351 replaced to MS5351, at same performance and lower price.(In fact I choose 5P49V6965 before, but too expensive and doesn't provide too much improvement)the other things are quite cheap. 1 dollar or less. 1 dollar, 1 dollar, 1 dollar...for example MP2122 1pcs at $0.14, TPS62480 1pcs at about $0.7. SOIC-8 150mil slot(just the FRAM/EEPROM in the diagram, you can replace it from the slot)(from LOTES) is a bit expensive, but bellow or about $1.of course you can unpopulate some of them.In fact the biggest tough thing for me is how to solder the big BGA FPGA to the board......

author: xvr
author_rank: Frequent Contributor
timestamp: April 11, 2024, 01:39:53 pm
content: > The XC7K70T-FBG484 cost me $22, the biggest part of course.Not so bad, I'd expect more expensive> 6 layers at PCBWAY i cost about $42 and get about 7 pics.$6 per single PCB. Could be cheaper.> n fact the biggest tough thing for me is how to solder the big BGA FPGA to the board......Yes, PCBA could be expensive, especially in singles quantities.So I'm still very interested in final price (for single piece and for small batch, say 100 pcs).If it will be less than $100 per piece (in small batch) it will be wonderful

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 01:55:53 pm
content: MaybeBut i am not interested in doing some kickstar.I think open sourcing is enough, and you can modify these, replace some ICs to reduce cost, or reroute the whole crappy lines.(The first time for me, so it is not very perfect, and some traces are ugly.)

author: xvr
author_rank: Frequent Contributor
timestamp: April 11, 2024, 02:35:46 pm
content: Unfortunately, open source is not enough. BGA chip is a quite hard to solder at home - it requires special equipment and experience. But PCBA in single quantities is a VERY expencive.

author: antercreeper
author_rank: Contributor
timestamp: April 11, 2024, 03:20:42 pm
content: I am about to try use a heating table below and a heat gun(maybe I should replant the solder ball to Pb ones for lower temperature requirement). And you will hear good or bad news soon. The manual from TI introduced this way.However, the experience in China is just go to look for some computer repair shops and let them sold these big BGA chips with BGA rework stations. for about $8.29 1 pcs :'(

author: langwadt
author_rank: Super Contributor
timestamp: April 11, 2024, 03:25:25 pm
content: Quote from: antercreeper on April 11, 2024, 01:26:54 pmmust have fallen of a truck somewhere, I think a regular distributor wants close to 10x that ...

author: dietert1
author_rank: Super Contributor
timestamp: April 11, 2024, 03:27:11 pm
content: This FPGA may have 1000 times the computing power you need for an audio application. Can you write some sentences about the application and how you arrived at using a FPGA for this? What is the large memory meant for? Is this a MP3 player? Is this for machine learning?Many years ago i made a special digital crossover for active speakers using a Spartan3 50K FPGA. Some years later i found the same could be implemented on an Arm Cortex 3. At the time a Kinetis K22. Cortex architecture includes a very nice DSP instruction set and at clock rates of 120 MHz you have about 1200 cycles per (stereo) audio sample if your audio stream is 96 KHz sampled. This was enough to implement two 4-ways time-correct crossovers.Regards, Dieter

author: xvr
author_rank: Frequent Contributor
timestamp: April 11, 2024, 03:29:03 pm
content: > However, the experience in China is just go to look for some computer repair shops and let them sold these big BGA chips with BGA rework stations. for about $8.29 1 pcs :'(Yes, in China it could be easy. But for the rest of the world it is very tricky. Here PE magazine says that some PCB requires expert to assemble it, just because some SMD of 0805 size was used

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 11, 2024, 10:25:03 pm
content: Quote from: langwadt on April 11, 2024, 03:25:25 pmYeah. While prices from Digikey and the like are not representative of the real price you can get in quantities, $22 looks pretty fishy. Possibly the price they get in China, but I personally wouldn't know which chinese distributor to get these from at this price. It's probably possible though as there are Kintex 7 dev boards from China for about $80.

author: antercreeper
author_rank: Contributor
timestamp: April 12, 2024, 12:18:16 am
content: 160t would be 2x price. maybe just because 70t is more common.(only common device is cheaper. :'()

author: antercreeper
author_rank: Contributor
timestamp: April 12, 2024, 12:20:19 am
content: In fact i just solder 0402s by hands.But for QFN and BGAs, you don't know if there are soldered properly. Factorys use x ray inspection machine.

author: antercreeper
author_rank: Contributor
timestamp: April 12, 2024, 12:27:01 am
content: Just4FunIn fact it is just a platform includes all you need to design and do verifications for any audio things. Of course you can make one AI core, or AI voice synthesizer.https://bellard.org/tsac/or LPCnet from Xiph.org. and then things will go from 1000% to 0%.By now I implemented the whole FLAC codec(A cpu core+LPC core) and used 20% resources.running at 50MHz.

author: antercreeper
author_rank: Contributor
timestamp: April 13, 2024, 04:14:40 am
content: all is done!However some plastic melted......

author: asmi
author_rank: Super Contributor
timestamp: April 17, 2024, 12:06:23 am
content: How are you planning to cool this part? It will cook itself in no time once you place any load onto it.

author: antercreeper
author_rank: Contributor
timestamp: April 20, 2024, 05:44:46 am
content: The FPGA? Maybe u can stuck a heat sink with some tape on it. It's my fault, haven't design holes for mounting heat sinks(no spare space).It depends on your design.For mine, almost no heat generated, about 20~30mA @1 volt VCCINT, as cool as the ambient. The hottest part is the FTDI FT2232 and MS5351M Clock, at about 40~45 degrees celsius.And in the second version, I connect the thermal signal to the FPGA reset pin(you can use it in your design), and can stuck your design if it overheated.

author: asmi
author_rank: Super Contributor
timestamp: April 23, 2024, 02:14:24 am
content: Quote from: antercreeper on April 20, 2024, 05:44:46 amWhat your design does? That seems way too low even for unprogrammed device.Quote from: antercreeper on April 20, 2024, 05:44:46 amThere are no "thermal signals" in FPGA. It's got internal ADC with die temperature sensor connected to one of it's channels, so you don't need any external connections, but you DO need to implement it in your design and do something about it.

author: antercreeper
author_rank: Contributor
timestamp: April 26, 2024, 02:57:42 am
content: Sorry for my bad English :'(I use TMP435 to monitor the diode of the FPGA and 1. trigger reset of your design while too hot 85 degrees 2. cut the Power while overheated, maybe 100 degrees.

author: antercreeper
author_rank: Contributor
timestamp: April 26, 2024, 03:00:59 am
content: The current is too small for 8millohms shunt resistors(and the solder can also add some resistors). i am sure just millamps, and I can't measure it very well.for thermal camera, it is as cold as the ambient...tips: max is 6 amps, 6*8=48millvolts

author: Sniper1
author_rank: Regular Contributor
timestamp: May 10, 2024, 06:00:28 pm
content: you can get a BGA heat sink for about 1-2$ since u are in china already maybe less and with some paste u are donw if u want to but yea if it does nothing it should consume like nothing maybe u should have put a few ICs for measuring stuff like thatWhat type of ASIC do u plann to simulate/design in the FPGA?

author: zapta
author_rank: Super Contributor
timestamp: June 17, 2024, 09:41:56 pm
content: What data rate to a host do you expect to get with the 'fast serial'? Have you considered wring the FT2232 also for asyncrhonous or synchronous FIFO mode for faster data link?