From aaa9fdf3a181d621fbdcb4533dc0ea719c2af0d2 Mon Sep 17 00:00:00 2001 From: jbruce12000 Date: Sun, 9 Dec 2018 15:00:56 -0500 Subject: [PATCH] - adding note about using gpio pin with ssr --- README.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 26cac0b..6f22acc 100644 --- a/README.md +++ b/README.md @@ -38,6 +38,8 @@ Turns a Raspberry Pi into a cheap, web-enabled kiln controller. The pi has three gpio pins connected to the MAX31855 chip. D0 is configured as an input and CS and CLK are outputs. The signal that controls the solid state relay starts as a gpio output which drives a transistor acting as a switch in front of it. This transistor provides 5V and plenty of current to control the ssr. Since only four gpio pins are in use, any pi can be used for this project. See the [config](https://github.com/jbruce12000/kiln-controller/blob/master/config.py) file for gpio pin configuration. +*Note: I tried to power my ssr directly using a gpio pin. The pin could not provide enough current (16ma max) to control my ssr. My ssr was rated at 25ma max current, and 3V minimum to switch so I figured it would work. YMMV.* + ![Image](https://github.com/jbruce12000/kiln-controller/blob/master/public/assets/images/schematic.png) ## Software @@ -53,7 +55,7 @@ Download [NOOBs](https://www.raspberrypi.org/downloads/noobs/). Copy files to an $ source venv/bin/activate $ pip install greenlet bottle gevent gevent-websocket -Note: the above steps work on ubuntu if you prefer +*Note: The above steps work on ubuntu if you prefer* ### Raspberry PI deployment