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Using 2 transmitters (315 and 433) with a NodeMCU ESP-12E

PostPosted: Thu Jan 05, 2017 3:58 pm
by psjoholm
Hi guys,

New to the forum and looks like a great source of information for my new hobby:)

Please keep in mind that I am a total noob to this board, but I am a highly technical person who is a network engineer by day.

I am currently working with the NodeMCU ESP-12E boards and using them with my home automation stuff to turn lights and fans on using an RF transmitter along with MQTT for sending the messaging to activate the setup.

Everything is fantastic and I absolutely loved tinkering with the code and building a little custom IoT device. I ended up building 2, one for 433Mhz and the other for 315Mhz.

What I don't like is that I currently have to have 2 of my boards occupied for this project and that I am also using up 2 times the electricity, since I need to have one for each frequency.

So, my question is. Could I possibly simply split the vin and d4 and send the signal to both of the transmitters or you think that the board does not have enough juice to power 2 transmitters at the same time?

There is no other voltage out on the board, right? My goal is to only use the micro usb for power, just FYI.

Thanks for any suggestion you may give. If you need any specifics on anything, I will gladly provide more.

Re: Using 2 transmitters (315 and 433) with a NodeMCU ESP-12

PostPosted: Sat Jan 28, 2017 9:22 am
by briancarney
hi i have just bought this device saleae 8 channel plus software from salaea site great for capturing rf output and inputs in binery and hex infact all modes
i a have captured data and i wish to send it via esp8266 to 433hmz transmitter if this helps you can you help me thanks brian briancarney@sky.com

Re: Using 2 transmitters (315 and 433) with a NodeMCU ESP-12

PostPosted: Mon Jan 30, 2017 6:23 pm
by g6ejd
Nearly every 433 and 315Mhz transmitter module on the market take miniscule amounts of power to operate, so unless your devices are different from the majority the uUSB power source is more than adequate. Also the input impedance of the transmitters is very high, so using D4 can easily drive two. But why not use another data pin so that you can send data to D3 and D3 for example. Difficult to be exact when the TX boards types and specifications are unknown.

You can only get 3.3v on a NodeMCU unless you have a break-out board then you can get 5v too.