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  • edh's Avatar
    11-09-2019, 08:46 AM
    Hi, I have experience of using multiple MCP23S107's - the SPI variant of the same chip you mention, and they work great - I currently have 7 of them hooked up to a Pi and via an ISR can reliably read 112 gpio's. I am in...
    5 replies | 205 view(s)
  • edh's Avatar
    10-30-2019, 11:07 AM
    An alternate solution would be to offload the PWM function to a PCA9685 16 channel 12 bit chip - these natively support phase shifting of the outputs to not only reduce total power draw but to also minimise EMI -...
    6 replies | 1069 view(s)
  • edh's Avatar
    10-30-2019, 10:59 AM
    Hi - I've used the SPI variant of these expanders - MCP23S17 and they work fine on the T4 and even with sub-optimal breadboard layout I have successfully overclocked them to 18MHz. In my use-case I am reading the...
    5 replies | 250 view(s)
  • edh's Avatar
    10-30-2019, 09:54 AM
    Take a look at - I have used that library with multiple MCP23S17 GPIO expanders on a T4 using interrupts to trigger reads from 112 end points. Originally wrote code in python...
    11 replies | 280 view(s)
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About edh

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About edh
long term DIY'er, fine woodwork, welding, basic electronics
Essex, UK
audio, building high-end speakers, IoT
IT infrastructure


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Lots of buttons for x-plane 11-09-2019 08:46 AM
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