Reddit mentions: The best dip switches

Most gas fireplaces today us a millivolt gas value. If your fireplace happens to have a fan switch or 120v available near the fireplace switch you maybe in luck. I used the 120v from the fan of my fireplace in parallel to power a relay and added a Lutron Caseta switch in series to turn the 120v on/off to the relay which in turn opens or closes the contacts for the low voltage solenoid. The added benefit of using a smart switch is being able to add it to my voice assistant Alexa or Home Assistant.

120v White wire -> relay <--> smart switch <- 120v Black wire

..................................coil.................................................................

......millivolt line<-> N.O. <-> millivolt line.......

Some more info on fireplace wiring.

There are fireplace remotes available depending on your fireplace's solenoid.

I'm in a similar situation and have been brainstorming about it for awhile. You have two options:

1. Ditch your current wireless system and run a wire to a converter that changes the millivolt signal to 24V.
   
   https://www.instructables.com/id/Nest-Thermostat-With-Gas-Fireplace-or-Other-Milliv/
   
   https://www.amazon.com/dp/B000LDBP9Q/?coliid=I28F84ZZZ5MVLS&colid=2UT1TBBXYOV2A&psc=0&ref_=lv_ov_lig_dp_it
   
   
2. Build your own wireless transmitter using Arduino and Raspberry Pi/Google Things/etc. I'm trying this option because my current remote has some unique settings. Here's the tutorial on how to get/transmit the wireless signal:
   
   https://arduinobasics.blogspot.com/2014/06/433-mhz-rf-module-with-arduino-tutorial.html
   
   ​
   
   Hopefully I'll be successful and post my results, but more likely I'll give up on being able to adjust flame height via my voice and just go with option 1. Good luck!

Edit: Look at livingplasma's post. They have your back.

You need a three position dip switch. I bought this (haven't actually used it, instead just use the default channel since I already ruined one trying to attach a dip switch): http://www.amazon.com/2-54mm-Pitch-Positions-Switch-Black/dp/B007QAJF5I/ref=sr_1_3?s=industrial&ie=UTF8&qid=1454111425&sr=1-3&keywords=3+position+dip+switch

You will solder 3 pins to CS1, CS2, CS3, and the legs on the opposite side of the switch to the top of the transmitter to ground the signals.

I can thank flitetest for the how-to: https://www.youtube.com/watch?v=nt6kYWbMQIM
That guy is fantastic at soldering, so be cautious.

I have a gas (millivolt) furnace and no 24v wiring in my house.

It’s a bit ugly, but I have this plugged into a wall outlet, which steps down voltage to 24v for a Nest Thermostat. It also has millivolt leads to connect to the switch terminals on your furnace. It was designed specifically for this sort of application.

Works perfectly so long as you don’t lose power, which happens to me frequently in the winter. My current solution to that is just a piece of wire I manually use to jump the furnace switch when I need heat. I’ll eventually replace it with a zwave thermostat that has a backup battery.

I don't really wanna post the code for ethical reasons (I started with some basic Adafruit code for bluetooth and turned it into a full OS). But here's a feature list:

1. Bluetooth, where time, battery percentage, and location are automagically updated by a companion app (a modified version of this app by Nordic Semiconductor.)
   
   
2. A stopwatch, accessed by pressing the left button.
   
   
3. A flashlight, turned on by one of the switches
   
   
4. A "dumb mode" in which only the time is displayed, accessed by flipping the bottom switch
   
   
5. In the future, notifications.
   
   I used u8g2's u8x8 mode for the screen drawing, as it requires no ram.
   
   ​
   
   Here are my parts:
   
   Voltage regulator (takes 8.4v down to 5v)
   
   22pF capacitors
   
   16MHz Oscillator (required for standalone board)
   
   DIYMall blue OLED
   
   Knockoff Arduino Uno
   
   Adafruit UART-Capable bluetooth module (makes sending data easier)
   
   Spare ATMega 328 processors
   
   Li-Ion" 9V" (8.4v) batteries (rechargeable)
   
   Switches
   
   9V battery clip
   
   Soldering Kit
   
   Elegoo prototyping PCBs
   
   Jumper wires (makes life easier & tidier)
   
   Elegoo Starter Kit (Comes with LEDs, resistors, and buttons)

Unfortunately Nest doesn't directly support reverse logic systems like yours (Y1 is used for cooling vs. yours needs to be not heating). Nest also doesn't like stranded wires.

​

Installing a simple relay at the valve would help change the logic so that you would have a W1 instead of a Y1 for heating.

It's possible with a little work. https://smile.amazon.com/Honeywell-R8845U-1003-Universal-Switching-Transformer/dp/B000LDBP9Q/ref=pd_rhf_eetyp_s_vtp_ses_clicks_1_1?_encoding=UTF8&pd_rd_i=B000LDBP9Q&pd_rd_r=2WWZCVT64DV8MC1AP15R&pd_rd_w=m5yx6&pd_rd_wg=VCXOJ&pf_rd_i=desktop-rhf&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=05d75987-58ed-4d36-bbfa-515cd87e4ee3&pf_rd_r=2WWZCVT64DV8MC1AP15R&pf_rd_s=desktop-rhf&pf_rd_t=40701&psc=1&refRID=2WWZCVT64DV8MC1AP15R

The lower DPST switch is an off-the-shelf power switch with an integrated LED that I will be using for master system power. The row of switches will be a DIP switch initially, to allow you to dial your current in quarter mA increments, although if I could come up with a rotary switch solution I might switch to it.

I have also bought an in-line analog current meter that goes to 3mA that I will use for at least the prototype, but the 'production' one probably won't have it as long as the dip switched CRD's are consistent and reliable.

All credit goes to http://speakwisdom.wordpress.com/2013/04/02/a-very-simple-current-regulated-tdcs-device/ for the idea and the stolen image.

By the way, if anyone is curious, here's my parts list:

Part with Link|# Per assy|cost/ea|cost/assy

--|:-:|:-:|:-:
10PC New 16A 12V Round Rocker Toggle Switch Green LED SPST For All| 1| $0.69|$0.69
10 Pcs 2.54mm Pitch 8 Positions 16 Pin Blue DIP Switch 8P| 1| $0.54|$0.54
DC 3mA Analog AMP Current Panel Meter Ammeter Gauge 85C1| 1 (optional)| $7.37|$7.37
50PCS J500 Manu:SI/VISHAY Encapsulation:TO-92,Current Regulator Diodes|8|$0.58|$4.64

As you can see from the list, I'm making more than one of these--my whole office heard the Radiolab podcast and as the designated nerd, asked me to Make It So.