From 155720b51ff18811276342ad2ff0cf88e4065681 Mon Sep 17 00:00:00 2001 From: Jordan Williams Date: Mon, 18 Nov 2024 09:41:19 -0600 Subject: [PATCH] Finesse the wiring documentation --- boards/pico/README.adoc | 30 ++++++++++++++++++------------ boards/qt-py-ch32v203/README.adoc | 30 ++++++++++++++++++------------ 2 files changed, 36 insertions(+), 24 deletions(-) diff --git a/boards/pico/README.adoc b/boards/pico/README.adoc index c848ec6..99bc77a 100644 --- a/boards/pico/README.adoc +++ b/boards/pico/README.adoc @@ -85,8 +85,8 @@ This is a dead-simple PWM fan controller that simply lowers the speed of the {No The microcontroller simply sets the fan speed and then does nothing. The fan setup might evolve in the future to take into account temperature sensing and dynamic speed adjustment. -The 3.3V Raspberry Pi Pico requires a logic-level shifter to boost the PWM signal up to 5V for the fan. -I use the 74AHCT125 to perform the logic-level conversion, using pin #40, `VBUS`, to provide the 5V reference voltage. +The 3.3V Raspberry Pi Pico requires a logic level shifter to boost the PWM signal up to 5V for the fan. +I use the 74AHCT125 to perform the logic level conversion, using pin #40, `VBUS`, to provide the 5V reference voltage. The Raspberry Pi Pico draws 1.99 mA of current in this particular configuration. @@ -96,28 +96,34 @@ The 74AHCT125 is wired as shown in the <<74AHCT125 Wiring>> table. All pins omitted from the table are connected to ground. .74AHCT125 Wiring -[cols="1,4"] +[cols="1,2,2"] |=== -| 74AHCT125 | Signal +| 74AHCT125 Pin +| Signal +| Connection -| 1 -| 3.3 Volt power +| 2 +| 3.3V logic level input +| Pico pin #20 (GP15) -| 9 -| 3.3 Volt PWM input signal +| 3 +| 5V logic level output +| 1N4001 to fan header pin #4 (Control) -| 10 -| 5 Volt PWM output signal +| 8 +| 5V +| Pico pin #40 (VBUS) |=== -The output signal from the logic-level shifter is sent through the 1N4001 power blocking diode to the fan header. +The output signal from the logic level shifter is sent through the 1N4001 power blocking diode to the fan header. The pins on the 4-pin fan header are classified in the <<4-pin Fan Header Pinout>> table. The pins are numbered one through four from left to right with the pins reaching upwards and the overhang positioned between the viewer and the pins. .4-pin Fan Header Pinout [cols="1,4"] |=== -| Fan Header Pin | Signal +| Fan Header Pin +| Signal | 1 | GND diff --git a/boards/qt-py-ch32v203/README.adoc b/boards/qt-py-ch32v203/README.adoc index baf3fb0..a4da0c6 100644 --- a/boards/qt-py-ch32v203/README.adoc +++ b/boards/qt-py-ch32v203/README.adoc @@ -72,8 +72,8 @@ This is a dead-simple PWM fan controller that simply lowers the speed of the {No The microcontroller simply sets the fan speed and then does nothing. The fan setup might evolve in the future to take into account temperature sensing and dynamic speed adjustment. -The 3.3V QT Py CH32V203 requires a logic-level shifter to boost the PWM signal up to 5V for the fan. -I use the 74AHCT125 to perform the logic-level conversion, using pin #40, `VBUS`, to provide the 5V reference voltage. +The 3.3V QT Py CH32V203 requires a logic level shifter to boost the PWM signal up to 5V for the fan. +I use the 74AHCT125 to perform the logic level conversion, using pin #40, `VBUS`, to provide the 5V reference voltage. The QT Py CH32V203 draws only 1.11 mA of current in this particular configuration. @@ -83,28 +83,34 @@ The 74AHCT125 is wired as shown in the <<74AHCT125 Wiring>> table. All pins omitted from the table are connected to ground. .74AHCT125 Wiring -[cols="1,4"] +[cols="1,2,2"] |=== -| 74AHCT125 | Signal +| 74AHCT125 Pin +| Signal +| Connection -| 1 -| 3.3 Volt power +| 2 +| 3.3V logic level input +| QT Py CH32V203 pin #5 (SDA) -| 9 -| 3.3 Volt PWM input signal +| 3 +| 5V logic level output +| 1N4001 to fan header pin #4 (Control) -| 10 -| 5 Volt PWM output signal +| 8 +| 5V +| QT Py CH32V203 pin #14 (5V) |=== -The output signal from the logic-level shifter is sent through the 1N4001 power blocking diode to the fan header. +The output signal from the logic level shifter is sent through the 1N4001 power blocking diode to the fan header. The pins on the 4-pin fan header are classified in the <<4-pin Fan Header Pinout>> table. The pins are numbered one through four from left to right with the pins reaching upwards and the overhang positioned between the viewer and the pins. .4-pin Fan Header Pinout [cols="1,4"] |=== -| Fan Header Pin | Signal +| Fan Header Pin +| Signal | 1 | GND