3 ms·

A microcontroller like STM32 would be cheaper and use less power for a fan controller, and would boot instantly and never crash.

rasz 5y ago
Still overkill, Commander Pro uses $10 8051 8-Bit 50MHz with 64KB flash and 8KB ram. CY8C3246AXI-138 https://www.cypress.com/part/cy8c3246axi-138 https://www.cypress.com/part/cy8c3246axi-138
- voxadam 5y ago
  CY8C32xxx processors are based around the 8051 but they're actually part of the fairly capable Cypress PSoC 3 line[1]. The PSoC 3 includes an 8501 compatible processor along with a bunch of mixed signal peripherals and a PLD fabric to connect it all. [1] https://www.cypress.com/products/psoc-3 https://www.cypress.com/products/psoc-3
- formerly_proven 5y ago
  And even a 7$/ku MCU is complete overkill (assuming that's the real price, not shortage-related, though its lead time is over a year, so the price is probably inflated), because literally any microcontroller with an ADC can easily do this. Around ten years ago I built my own on a tiny AVR, and even that would be an expensive option compared to what you could use instead in a commercial product (<0.5 $/ku ARM MCUs). I haven't had a fan controller for many years though, because they're quite pointless if you do things right.
  - rasz 5y ago
    CY8C3246 used to be $5-3.75. Cypress chips were always expensive. Ever since I saw them they always cost as much as separate mcu + separate CPLD.
- intpx 5y ago
  Still overkill. A 555IC, a variable resistor, a thermistor and a few passives is all you need. You could get the BOM for the whole #! down to under a buck.
unwind 5y ago
They do, you know, run software. Software is sometimes kind of hard to get right, which can lead to crashes even in microcontrollers. Source: worked as an embedded software developer on mostly STM32s for about 7 years. Did see crashes occasionally.
- brokenmachine 5y ago
  Agreed but definitely must be quite a few orders of magnitude less crashes than a rPi for a fan controller.

rasz 5y ago

Still overkill, Commander Pro uses $10 8051 8-Bit 50MHz with 64KB flash and 8KB ram. CY8C3246AXI-138 https://www.cypress.com/part/cy8c3246axi-138 https://www.cypress.com/part/cy8c3246axi-138

voxadam 5y ago
CY8C32xxx processors are based around the 8051 but they're actually part of the fairly capable Cypress PSoC 3 line[1]. The PSoC 3 includes an 8501 compatible processor along with a bunch of mixed signal peripherals and a PLD fabric to connect it all. [1] https://www.cypress.com/products/psoc-3 https://www.cypress.com/products/psoc-3
formerly_proven 5y ago
And even a 7$/ku MCU is complete overkill (assuming that's the real price, not shortage-related, though its lead time is over a year, so the price is probably inflated), because literally any microcontroller with an ADC can easily do this. Around ten years ago I built my own on a tiny AVR, and even that would be an expensive option compared to what you could use instead in a commercial product (<0.5 $/ku ARM MCUs). I haven't had a fan controller for many years though, because they're quite pointless if you do things right.
- rasz 5y ago
  CY8C3246 used to be $5-3.75. Cypress chips were always expensive. Ever since I saw them they always cost as much as separate mcu + separate CPLD.
intpx 5y ago
Still overkill. A 555IC, a variable resistor, a thermistor and a few passives is all you need. You could get the BOM for the whole #! down to under a buck.

unwind 5y ago

They do, you know, run software. Software is sometimes kind of hard to get right, which can lead to crashes even in microcontrollers. Source: worked as an embedded software developer on mostly STM32s for about 7 years. Did see crashes occasionally.

brokenmachine 5y ago
Agreed but definitely must be quite a few orders of magnitude less crashes than a rPi for a fan controller.