(Part 2) Top products from r/esp8266

First question - I use exactly one of those SSR's in my sous vide controller to control a 500W cartridge heater. You will have to use a heat sink. Even driving a 500W load it gets too hot without one, even at lower duty cycles. You can get them with a bulky heat sink that works great, but I salvaged a chipset heat sink from an old motherboard that was a bit more compact. You might even need active cooling (a fan) driving a 10A load depending on how big of a heat sink is practical, which is a big complication.

Side note: Big Clive has a detailed teardown of that relay where he discusses it in quite a bit of detail.

Second question: GPIO2 has a pullup resistor because that is needed for the ESP to boot, so it will always be high at start. Really the best option is to get a more convenient ESP8266 board like a Wemos D1 Mini or NodeMCU, which expose more GPIOs that don't have pullups. GPIO 4 or 5 are what I tend to use.

I'm not sure what you mean by a PNP-NPN pair, something like this? You can just use a level shifter, but I'm 99.99% sure you can drive those Fostek relays directly with 3.3V no problem. They are fine operating near the voltage threshold because they have a driver circuit inside.

Metal container will murder the wifi signal for sure. Especially since that enclosure is probably grounded since it's a mains powered appliance it'll act like a Faraday cage. I'd be surprised if you really got any signal at all.

Just my $0.02 and don't let me stop you, but you'd probably be safest buying something premade like the Sonoff TH16. It's rated for 16 amps, but you can assume it actually lives up to that (Itead is pretty legit) so that should be a decent safety margin. And it's an ESP8266 board that has all the headers exposed for programming so you can hack it to your heart's content. If you're in it for the learning then by all means get your design working... and then buy something made professionally to use for real. It's just not worth the risk of burning the house down when the Sonoff devices are so affordable.

Also agreeing with /u/lukeimyomama, an SSR is a bad choice here since they tend to fail short. If the heater has a built in safety that's not the worst thing, but still I think I'd rather have a coil relay. They also dissipate way less heat (virtually none), which is a major annoyance if you use the SSR. The biggest reason to prefer an SSR is that you can PWM them since they switch states very fast. That's why I use it in my sous vide, so I can have pseudo-analog temperature control, but that's not what you want to do. You are controlling the power at the heater, so the relay will be open or closed all the time. A higher current rated coil relay will be much easier.

Unfortunately I was hoping to use RGB LEDS, I can't believe I didn't specify that. Sorry about that, I edited it in. Would you be able to explain the common cathode vs common anode? I'll be looking it up but just to make sure I have the right idea for it.

 

I'll more than likely be using a relay at first, following tlucas's comment above just to get a bit of a better understanding but will be pushing to move over to a more complicated setup using transistors as they seem to be more efficient.

 

Ah yes I had picked out a multimeter but is there a type that you would suggest? I wouldn't be against learning how to make a board, i've looked at tutorials and it seems reasonably simple for just a basic board with no special features. I looked into the materials for a board, but the only thing I haven't figured out is the dremel. Should I go with a handheld one or would a standing one be better?

Edit: It seems like the standing one would be better, however people aren't too fond of that one I linked, I may end up going with a drill press

hey, the relay won't work very well if you're using RGB LEDs. One of the coolest features of RGB is the ability to mix colours by pulsing each in sequence for different amounts of time. The relay may not be able to switch fast enough, and you'd need of for each 'colour'.

Personally I don't find the Reddit format to be the best for asking these types of questions, as often the 'popular vote' goes to the answers that are short and easy to understand, which may not be the 'best' answer. I prefer http://www.eevblog.com/forum/index.php and the related electronics vblogs, and https://electronics.stackexchange.com/.

For a great mid-range multimeter I love the Extech EX330 (https://www.amazon.ca/gp/product/B000EX0AE4/ref=oh_aui_search_detailpage?ie=UTF8&psc=1), especially with its built-in non-contact voltage detection for working on household wiring (not related, but it's so handy!). The Fluke 87-V is, in my opinion, the cream of the crop and priced accordingly. There are cheap multimeters for $5 that will get the job done, and I do keep these in my vehicles -- eBay and a month of shipping time works well here. Searching eevblog.com for "shootout" (search Google for "site:eevblog.com shootout") reveals great comparisons, too many to read through but indulge the a bit to get a feel for what to look for.

Forgive the 100% newbness, but I'm thinking of doing this as my first electronics project (I'm a software engineer by day).

I created a slightly different parts list through adafruit.com here: ESP8266 BTC ticker parts.

The main differences are:

• Instead of the FTDI Basic Breakout, I'm hoping to use the FTDI Serial TTL-232 USB Cable
  
• I swapped the Monochrome 0.96" 128x64 OLED for the Monochrome 128x32 I2C OLED
  
• I couldn't find 330 ohm resistors, wondering if 220 ohm or 470 ohm would suffice?
  
  Do you think I could work through the tutorial with my altered parts lists? Also, how to power this device on its own? Should I purchase a battery as well?
  
  Thanks for any help in advance!

This is the polar opposite of SMD, but I thought I'd share my solution...

While I love DIY, smoke detectors are important. I wanted to interface with my home system but without compromising the integrity of the system.

Get a 120v first alert.
First Alert SA521CN Wireless Interconnected Hardwired Photoelectric Smoke Alarm with Battery Backup https://www.amazon.com/dp/B000EVO9D4

Get the smart relay interconnect.
BRK RM4 Smart Relay for First Alert https://www.amazon.com/dp/B0039PF21U
This includes schematic for wiring to the detector and the color codes for NO/NC relay connection.

~~Get an optocoupler or isolation relay. Mains Voltage! The output of the RM4 is 120V.
Enclosed AC/DC Power Relay with Protection & De-Bounce. Screw Terminals. 120V Trigger Input. https://www.amazon.com/dp/B017743I7S
The RM4 output powers the relay. The screw terminals connect to the 8266.~~

Get a Esp8266; Flash tasmota firmware. Configure for switch and mqtt. Wire it up.
First Alert is now part of the matrix.

Quick update: Did not need the second relay/optocoupler. The BRK RM4 is an isolated relay. Their docs did not make that perfectly clear so I assumed worst case w/o testing it.

There are devices like this one on amazon for under $10 which do what you want.

I don't want to discourage you from a DIY project as I personally appreciate a reason to build something. If you are wanting to pursue this to learn about the ESP8266 and building circuits, sounds like a great project. If you are just looking for a simple solution, I've used the $10 above for years and it has worked fine.

I spent a long time trying to find ESP resources too, I can't help you breadboard it, but this is what I use for my ESP-01Ss:

https://www.amazon.com/gp/product/B01J2UXXCA/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

You'll see in the reviews of that item that you need to add a push button to it (literally 2 solder points, and there are pictures)

Something like this would work, you might be able to find cheaper:

https://www.amazon.com/microtivity-IM206-6x6x6mm-Tact-Switch/dp/B004RXKWI6/ref=sr_1_2?keywords=push+button+arduino&qid=1564884279&s=electronics&sr=1-2


Once you have the development board with the push button on it, you put in the ESP-01S, hold down the button while you insert the usb to your PC, then run whatever software you want to write to the esp.


Hope this helps!

I recently bought one of these for myself and I couldn't be happier as a DIY hobbyist:

Hakko Dial type temperature limiting soldering iron FX600

I only use it for hobby stuff such as Quadcopters, 3D printers and electronics kits but it's way better than the 8watt USB powered I was using before.

Pair it with this and this and you should be good for a while and roughly within budget.

For real PoE (and if you already have a PoE switch), you can use a TP-Link splitter at the MCU end. Trust me, 10 quid is cheap compared to some of the "PoE shields" you can find online.

Also noticed this on ebay. Is that an ENC28J60 integrated with an ATMEGA328? Looks cheap and cheerful.

pot adjustable buck converters, for projects that have a constant power source, they work great.

but like i said i haven't tested them with batteries at all.

https://www.amazon.com/gp/product/B014Y3OT6Y/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B008BHAOQO/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

> https://learn.adafruit.com/adafruit-huzzah-esp8266-breakout/overview

I have the exact board, and I also had issues powering it from a USB port. I'm currently using this power supply and have had 0 issues so far. I highly recommend a supply like this because it easily plugs into a solderless breadboard and can supply both 3.3v and 5v simultaneously. I combined it with this AC adapter. It's 9v, but the voltage regulators on the power supply will burn off the extra voltage as heat.

So now you can omit the voltage wire from the FTDI chip, but you still need a ground wire to go from the FTDI chip to the breadboard's ground.

Also, buy a multimeter if you don't already have one.

https://www.youtube.com/watch?v=IaKEYEyrRgk is a really good example

You can use REALLYYY cheap SDRs to get a very accurate picture of what's going on in the RF spectrum. If you're a windows user you can use SDR-Sharp.

https://smile.amazon.com/NooElec-NESDR-Mini-Compatible-Packages/dp/B009U7WZCA/ref=sr_1_4?ie=UTF8&qid=1502224074&sr=8-4&keywords=rtl+sdr ($20 Prime, but you can get them ~$10 from China) There are many other varieties.

Here's the code. I used this for the current transformer. This doesn't have the changes when I added the well pump monitor but the logic is mostly the same.

Mediabridge USB 2.0 - Micro-USB... https://www.amazon.com/dp/B004GF8TIK?ref=ppx_pop_mob_ap_share

There's the HC-06 BT module which can interface with an ESP-8266 or an Arduino.

• https://www.amazon.com/JBtek-Bluetooth-Converter-Serial-Communication/dp/B00L08GA4Q
  
  The makers of the ESP8266 have announced a new chip/module called the ESP32 with more I/O lines, WiFi, and BlueTooth. It's supposed to ship this year, though they may be behind schedule.

It's also called U.FL. For example this one definitely works:
https://www.amazon.com/dp/B00ZBJNO9O

I've been working on a similar version as to what you are building. You really ought to have your sensors in a shield where the sun is blocked. That clear enclosure will heat up in direct sunlight so the panel will charge.

I got one of these to put my sensors in, and the electronics are in a weather proof box with the solar panel:

https://www.amazon.com/gp/aw/d/B00VSXENM4/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8

Regardless, great work. I was using an Arduino fio to do mine, but I'm working on using the esp instead because of lower power consumption.

You can always do barometric pressure inside, it doesn't have to be on an outdoor unit, it's the same inside and out according to all of my experimentation.

What are you using to view your data? Webpage, control system, some sort of IoT service?

You can buy smoke in a can .
Arduino engineers hate him/her due to this one small trick......