Shared Projects by alanlord

A Dual Channel board for PWM fan control. Supports two fans from a single DC supply. Designed for a 3D printer but should be usable for other applications too. Choose suitable N-Channel Mosfets with a TO-252 footprint. R2 and R4 are current limiting resistors for the LEDs (D1 & D3) so again choose according your specs (SMD 1206 footprint). R1 and R3 are pull-down resistors - chose values based on your signal voltage and the mosfet’s gate voltage specification. D2 & D4 are to prevent back-emf from the fan motors and I recommend using 1N4007 for this. The fan connections on board are designed for JST XH and the signal connections are JST PH. The DC in is for a 5mm pitch 2 pin screw block.

I am now using this board and it is working. You just need to chose the right components for your application.

This is a first try at making tool-heads for 3D printers easier to re-wire/change. You’ll need:

• 2 of these PCBs
• 6 x 3pin &
• 6 x 2 pin &
• 2 x 4 pin JST PH connectors,
• 2 x 2 pin XH connector for the cartridge heater &
• 2 x 22pin Molex Milli-grid.

Create your own cable using either the 22pin milli-grid crimp plug or they also make a ribbon IDC plug. I used the normal individual crimp pin plug. Wire the cable pin-to-pin, e.g. pin 1 at one end goes to pin 1 at the other.

Then cable each component to the PCB on the tool-head end and each connector to the relevant board connection on your printer control board(s).

The bottom left sensor connector of the three (as you look at the top layout) is parallel connected to a three pin Dupont layout on the underside of the board - This allows me to plug in a Precision Piezo P20 probe detector.

NB: The three sensor connectors share a common +ve and -ve rail in the main wiring from the Molex connector - only the signal pins are independent. This might be an issue if you use mechanical (2 pin) end-stop switches rather than 3 pin optical devices. The reason why there are three sensor connectors was to be flexible for applications. It might be the case you need a probe and a MIN and MAX stop sensor. Of course you do not need to use all three. In my current CoreXY I use one for X Min and one for my Precision Piezo probe.

For an ESP8266, with programming connectors and switches and supporting Deep Sleep mode. Designed to connect to a BME280 Temp/Humidity/Barometer by wire using I2C.

BOM

• C1 1uF 1206 SMD
• C2 10uF 1206 SMD
• P1 JST XH B04B 4 Pin Straight
• P2 2 Pin Header Straight
• P3 6 Pin Header Straight
• P4 JST XH B02B 2 Pin Straight
• R1 0R 1206 SMD 1%
• R2 4.7K 1206 SMD 1%
• R3 4.7K 1206 SMD 1%
• R6 4.7K 1206 SMD 1%
• SW1 ALPS SKQGAFE010 SMD Tactile NO
• SW2 ALPS SKQGAFE010 SMD Tactile NO
• U1 ESP-12F
• U2 MCP1700T-3302E/TT SOT-23

The board design has been updated since this version:

• I missed off a pull up resistor on CH_PD (but can easily be tacked on the back of the board if you use this version)
• redesigned the layout so my fingers could get at the switches ;-)
• Added a switch to bypass the regulator so the circuit could be used either with 3.2v LifePO4, or 3.7v Li-ion batteries

All updates on my github repo here: https://github.com/theopensourcerer/esp8266_envmonitor

(UNTESTED)

ESP8266-12 based temperature sensor. Using a waterproof DS18B20 1-wire sensor. Board powered from 12v DC using a switching regulator (Murata OKI 78SR)

• All resistors are 1206 SMD 4.7k
• All capacitors are 1206 10uF ceramic
• Main connectors are JST XH style.
• Tactile Switches are ALPS SKQGAFE010 SMD Tactile NO
• Switching Regulator is OKI-78SR-3.3/1.5-W36-C

Project details all on Github: https://github.com/theopensourcerer/esp8266-external-temp-sensor