Original question:
Hi there:
customer side would like to check the R.P.M reading of AMC6821 register whether match the real case FAN speed.
But the reading from 0x08 & 0x09 was always 0xff, may we know the how to read the speed correctly?
and from the tool set of EVM, we know could convert the RPM reading from register, but how is that work?
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thanks again.
Hi Megan:
To attache the schematic of customer side , for the configuration register 1 & 2 would check with RD again.
Kay,
Thank you for your patience while we gathered data. We set configuration register 1 to 0x15 and configuration register 2 to 0x3f (from the information you gave us), and kept the other registers to default. Below shows the register values from the GUI that we used, and I've attached our configuration file (if you are using our GUI).
21 49 3 15 3F 83 8 0 0 20 19 19 3C 0 46 50 0 64 50 0 69 1D 55 55 52 41 61 B3 8 FF FF 0 0 FF FF 0 0
We were able to read RPM values from the EVM GUI as shown in the image below, as well as provided an example waveform from the TACH pin.
I would try changing the registers back to their default values and changing only configuration register 1 & 2 and see if you are able to read from the TACH pin.
Best,
Megan
