You mean the LM Remote module or the RF portion of the HeaterMeter board? The RF portion is just an RFM12B module.
The LM Remote... apparently I do not have a schematic for this. There's just about nothing to it, the big question comes from where do you get your 3.3V to run it.
The 16MHz resonator is optional if you don't mind setting your fuses to 8MHz. The FTDI is optional if you don't need serial output.
OK that is pretty standard and it looks like I can use my Uno and a bread board to test it all out.
My plan is to use it as my servo controller. With the hopes of getting the software to control the servo added to the HM.
I see a couple ways to get power:
1. Set the fan speed to manual 100% and just use that as a 12V supply and generate the power on the board.
2. Use 4 AA batteries and a LDO regulator to create the 3.3v and a separate 6V for the servo.
I don't know what the run time on the batteries are, but I got to start somewhere.
Yeah the design is super basic. Just a standard ATmega running on 3.3V with SPI connected to the radio. The main difference between the measuring circuit on this and a HeaterMeter is that instead of the probe just being pulled up to 3.3V, it is attached to a digital line which can be turned on and off to save power.
You can't set the fan speed to 100% manual and also expect to get the automatic fan speed as well because if the PID is running in manual the fan speed is whatever manual is set to. It would be less hokey to just use a power splitter (like a Y-cable) to power them both from the same 12V adapter. The LMRemote code itself can run for months continuously on a single AA battery (stepped up to 3.3V). However, I'm not sure how much that's going to be affected by keeping the receiver turned on all the time but it will be pretty significant. Something along the lines of 15mA vs 100uA.
You haven't mentioned it so I'll just make sure you're aware that the RFM12B modules are not 5V tolerant so you can't just hook them up to the Uno, you've got to use some of those 4.7k/10k level dividers like the HeaterMeter v3 boards have.
You can put all the probes on the lmremote unit if you want. I had considered this way way long ago, with the blower built into the remote unit as well but had to slap myself because then I was wondering what the point of the HeaterMeter was, if everything was built into the remote.
They make 2 types of the pinless RFM12B. One has a standard size crystal and the other has a little chip crystal. I've used both and they're functionally equivalent. So no worries there!
Before I was making boards, I'd just solder solid core wires (from a chunk of ethernet cable) onto the little indentions. You don't need all the pins, just SDI, SDO, SCK, CS, 3V3, GND and INT. Also solder on a piece of wire for an antenna. For one project I made a little adapter board to break it out onto pinheaders, but that was more trouble than it was worth. I think I printed half a dozen using a laser printer, an iron, HCl, and H2O2 and only one was good enough to work.
Sweet! Sorry to put you through so much troubleshooting due to my incompetence. You can get a single file from github by replacing "blob" with "raw" in the url:BTW is there an easy way to just download a single file from github? I always have to download the entire zip, the extract the one file I need.