FAN Manual Control

[zigastegu]

How to check if board drives FAN output correctly?

1. Wait for the temperature to raise above 55°C for FAN to turn on, and below 45°C again to turn OFF
2. Manual option?

Fan is driven with FAN_CTRL signal from FPGA. FPGA internally has NIOS2 cpu instance that sets temperature module LM75 to hysteresis 45 and 55°C with output signal which is rerouted through FPGA input through internal MUX to FAN_CTRL (E4) output

Hardcoded test:

• periphcfg.vhd reserves memory:

  mem(12) <= "000000000000000x"; --  0 free, PERIPH_OUTPUT_OVRD_0
  mem(13) <= "000000000000000x"; --  0 free, PERIPH_OUTPUT_VAL_0

  default values are both 0 and further uses LSB bits for driving FAN_CTRL (see photo above) changing LSB of mem(12) changes source and mem(13) is manual signal

I have compiled 2 versions based on https://github.com/myriadrf/LimeSDR-USB_GW/commit/0f021ca1b6faf9a09b5736b25f60ee6e562a5822: and used LimeUtil.exe to flash them on FPGA [test_FPGA_Fan.zip]()

WIP: I think changing this memory addresses is possible over SPI as LimeSuite GUI implements features for 16bit spi board writing also "cpu" in FPGA handles writing for GPIO Q: Main question what is the offset address? Do need to change any other register before writing this address? FPGA SPI Slave Select?

Hopefully digging through implementation of GUI FPGA GPIO will give us answers

[zigastegu]

I was so close :) offsets are: 0xCC - 0 = auto, 1= manual 0xCD - 0 = off, 1 = on