wifi slice throughput
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- Experienced Member
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wifi slice throughput
Hi, i am thinking about using the wifi stack using the TI wifi module to get an XMOS project to wifi. In the announcement of the wifi slice on this page https://www.xmos.com/products/xkits/slicekit it says the throughput max is 7Mbps but i am wondering is that due to the SPI speed limit between XMOS core and CC3000 or the limit is on the wifi chip or on the on air throughput? in short what is the bottleneck of this 7Mbps? Anyone knows? thanks!
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- Experienced Member
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The 7 Mbps limit is due to the maximum SPI clock rate of the WiFi module.
LSR TiWi-SL
The maximum theoretical WiFi throughput of the module is 54 Mbps, but that can't be sustained over multiple packets because of the SPI limit.
LSR TiWi-SL
The maximum theoretical WiFi throughput of the module is 54 Mbps, but that can't be sustained over multiple packets because of the SPI limit.
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- Experienced Member
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Speaking of the CC3000, has anyone seen the "always-on sensing" problem with the wi-fi slice? Here's a note about it: CC3000 always-on sensing I was planning to integrate the wi-fi slice, or the AdaFruit CC3000 breakout board into a project and I came across this warning about the module:
Search the internet for "cc3000 always-on sensing" for a good article that discusses flaws in the cc3000 firmware (not the drivers or the breakout boards themselves) that prevent this and other cc3000 devices from companies like spark fun and adafruit from being used in reliable applications that demand always on functionality. Apparently even with frequent reboots the chip will hang unpredictably. I see no discussion about this at either adafruit or spark fun.
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- Experienced Member
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thats very interesting ahenshaw, i think i actually have that problem with my wifi slice and i submitted a ticket about it.
Running the demo application on the slicekit gives me this:
**WELCOME TO THE SIMPLE WEBSERVER DEMO**
Switching on Wi-Fi module.... ok!
Scanning available networks....
Running the demo application on the slicekit gives me this:
**WELCOME TO THE SIMPLE WEBSERVER DEMO**
Switching on Wi-Fi module.... ok!
Scanning available networks....
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- XCore Legend
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There is a pwr_en pin accessible on the wifi slice, however not having used it I don't know if this is just a sleep pin or an actually a real power control that would enable power cycling on the CC3000 to clear the deadlock.
regards
Al
regards
Al
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- Experienced Member
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Ah, yes! Very good. It does look like that could be used to perform a reset. The AdaFruit board also has a VBAT_EN pin, which appears to provide the same function.There is a pwr_en pin accessible on the wifi slice ...