RC80 Question

[mloebl]

Hello,

Just got an RC80 thermostat off Ebay which claims to be new and an RC80B... however of course didn't come with manuals and I'm not sure if it really is an RC80B. The backlight is off if it has one and I read on the forum you can turn it off. How do I turn on the backlight?

Thanks!

-Mike

[Rupp]

Here's the manual. I could find the manual for an 80B so this may not help.

http://www.smarthome.com/manuals/110801Binstall.pdf

[mloebl]

Thanks for the link Rupp. I had been looking at that but still no luck. Other thing I'm not too sure of is it mentions the COMM line in the back, which currently has the 4 pin connector with wires. Do you remove that 4 pin connector and leave it floating when you connect to it for serial comm?

Thanks,

-Mike

[Rupp]

Mike,
I wish I could help but I do not own this stat. Hopefully some of the guys will be back this weekend and can give you some guidance.

[wegienka]

Mike,
I am not sure about the backlight. I have a couple new RC-122Bs that are hooked to the HVAC system, but not yet to HS. The backlight comes on when you press any of the keys on the stat.

I'm not sure what you are asking in terms of the 4 pin connector. That is the connector that you hook your serial comm line to.

The other thing about the Bs that I have heard but not experienced personally is that you should have a common wire installed within the HVAC wiring and not use the power stealing feature if you are going to use the backlight. There have been some reports of stats resetting when in this configuration.

I'm hopefully going to get my 122s hooked up to HS this weekend so I might be a bit more knowledgable next week.

Alan

[mloebl]

Alan,

Thanks for the reply. I did notice that there is a pair of wires going from the RGCYB to the LCD display from the looks of it so figured it was leaching from there. However when I opened up the furnace control unit, I did find an aux powersupply wired in. Though as with Murphy's Law, I forgot my meter at work so couldn't see if it was actually live or not...

I'm a bit confused as how you actually connect the serial cable to it. I understand how to wire the cable itself. What I don't understand is that the thermostat ships with a 4pin connector, with wires, already plugged into where it says COMM on the pcb. Does the serial cable I make plug directly into to the PCB connector itself, or do I connect to that 4pin wired connector?

Thanks,

-Mike

[wegienka]

Mike,
Here are some instruction on building a cable from the PC to the thermostat. The cable connects to the wires on the connector you are referring to.

If using a DB-9F connector:
1. On the DB-9F connector: Connect pins 7 and 8 together. (RTS and CTS)
2. On the DB-9F connector: Connect pins 1, 6 and 4 together. (DCD, DTR and DSR)
3. Connect pin 4 of the DB-9F to the YELLOW wire on the thermostat plug (DTR)
4. Connect pin 3 of the DB-9F to the GREEN wire on the thermostat plug (TXD)
5. Connect pin 2 of the DB-9F to the RED wire on the thermostat plug (RXD)
6. Connect pin 5 of the DB-9F to the BLACK wire on the thermostat plug. (GND)

If using a DB-25F connector:
1. On the DB-25F connector: Connect pins 4 and 5 together. (RTS and CTS)
2. On the DB-25F connector: Connect pins 8, 6 and 20 together. (DCD, DTR and DSR)
3. Connect pin 20 of the DB-25F to the YELLOW wire on the thermostat plug (DTR)
4. Connect pin 2 of the DB-25F to the GREEN wire on the thermostat plug (TXD)
5. Connect pin 3 of the DB-25F to the RED wire on the thermostat plug (RXD)
6. Connect pin 7 of the DB-25F to the BLACK wire on the thermostat plug. (GND)

Let me know if you still have any questions,
Alan

[mloebl]

Mike,
Here are some instruction on building a cable from the PC to the thermostat. The cable connects to the wires on the connector you are referring to.

If using a DB-9F connector:
1. On the DB-9F connector: Connect pins 7 and 8 together. (RTS and CTS)
2. On the DB-9F connector: Connect pins 1, 6 and 4 together. (DCD, DTR and DSR)
3. Connect pin 4 of the DB-9F to the YELLOW wire on the thermostat plug (DTR)
4. Connect pin 3 of the DB-9F to the GREEN wire on the thermostat plug (TXD)
5. Connect pin 2 of the DB-9F to the RED wire on the thermostat plug (RXD)
6. Connect pin 5 of the DB-9F to the BLACK wire on the thermostat plug. (GND)
...
Let me know if you still have any questions,
Alan

Alan,

Great, Thank you! So it's the CONNECTOR not the "comm" on the PCB; that makes a heck of a lot more sense. Did you get a 4 pin male connector to plug in, clip the wires and direct connect, or just insert the wires directly into the connector?

Thanks!

-Mike

[mloebl]

Just got my answer from HAI about the backlight. Apparently there is a jumper (or supposed to be ) in the back. I don't remember seeing it there so maybe I have a different model, but will have to check when I get home.

-Mike

[wegienka]

Mike,
I believe the thermostat has a 4 pin male connector on the PCB and a female connector with 4 short pieces of wire connected to it. I connected my serial comm cable with to the short pieces of wire on the connected and plugged it into the connector on the board.

Alan

[mloebl]

Alan,

Ok, that makes sense. I must be missing that piece then but shouldn't be too hard for me to make one. I attached what the back looks like on mine. I already have a 4pin connector plugged into comm going in a daughterboard in the front so if I unplug it, it will disable the comm to that board.



-Mike

[OldEE]

Backlighting

I think I purchased 2 of the same RC-80Bs! The manual shows backlighting setup: JP2 in the attached assembly drawing, but these units don't have the pins or even pads placed in these locations. I think we must have earlier models and need someone's assistance in identifying the "older" location for JP2. Any suggestions?

(I should have placed my other post on this same topic here - sorry.)

[OldEE]

Serial Interface

Mike,

One more detail on the RS232 interface. If you follow the "extra" RS232 wires in these ebay units, they travel to another PC board underneath the main board. This 2nd board is not refereced in any of the documentation and appears to have a wireless receiver for wireless access. It also gets its power from two other jumpers to the main connection pins. I have disconnected this 2nd board altogether.

Steve

[mloebl]

Steve,

Yup, must be the same ones (for $109) . I spoke to the guy and he was very apologetic and offered my money back, but the backlight really wasn't the end of the world for me. I took it apart and noticed the same thing about the wireless transmitter. They appear to be the origional RC80s with no backlight at all. I haven't tried calling HAI, but from googling on the web, it appears that's the case.

I got it working late last night by taking and old 4 pin sound card to CDrom speaker cable, and connecting that to some cat5, and then ran that to an old cisco terminal adapter. Long story short is it worked on the first try last night with the HAI plugin and seems pretty reliable. It's a joy coming from the RCS X10 thermostat which has the lovely set and pray feature sometimes unless a prestine x10 network...

-Mike

[OldEE]

Add backlighting?

Mike-
Are you convinced that there are no backlighting LED's in these older units? Perhaps its there but was never wired in.

If its not there, we could add a couple of LED's at the edge of the LCD diplay.