I'm hooking up 4 8bit A/D converters, they are high speed units which do 800,000 samples per second, They output 8 full bits, not serial, I don't know that spi or other serial protocols could keep up with 4 A/D converters....
I wish the address lines were output directly, then I could memory map the A/D's into the memory of the cpu directly.
Sampling for about 4 seconds of each gives 800K * 4 = 3.2Million 8 bit samples per second, 3.2 megabytes per second for 4 seconds (maybe upto 10 seconds) I think the GPIO can handle reading this fast, but don't think putting shift registers/SPI, I2C in the mix would keep up. PLEASE correct me if I'm wrong!
I'm actually using 3 pine boards to read 12 A/D channels, then using a 4th pine to aggregate the data for display
Another concern, since my 4 a-d converters do 800K samples/second 8 bits per sample....that 3.2megabytes per second data rate needs to be done for say 10 seconds max, or 32 megabytes.
Does anyone know if I can write a little assembly routine to malloc 32megs, then completely disable all interrupts for 10 seconds while the samples are gathered, then re-enable interrupts and throw the 32 megs out the ethernet port?
I don't want any 'interruptions' during the 10 second sample period, they would cause issues with the data collected
I wish the address lines were output directly, then I could memory map the A/D's into the memory of the cpu directly.
Sampling for about 4 seconds of each gives 800K * 4 = 3.2Million 8 bit samples per second, 3.2 megabytes per second for 4 seconds (maybe upto 10 seconds) I think the GPIO can handle reading this fast, but don't think putting shift registers/SPI, I2C in the mix would keep up. PLEASE correct me if I'm wrong!
I'm actually using 3 pine boards to read 12 A/D channels, then using a 4th pine to aggregate the data for display
Another concern, since my 4 a-d converters do 800K samples/second 8 bits per sample....that 3.2megabytes per second data rate needs to be done for say 10 seconds max, or 32 megabytes.
Does anyone know if I can write a little assembly routine to malloc 32megs, then completely disable all interrupts for 10 seconds while the samples are gathered, then re-enable interrupts and throw the 32 megs out the ethernet port?
I don't want any 'interruptions' during the 10 second sample period, they would cause issues with the data collected