I've been using these RF Transmitters, and they've been working just fine in my basic applications. But I've come to suspect I may have them hooked up wrong, as the screen printed pin labels are misprinted.
I've been using VCC and GND on the outsides, and middle pin as DATA. Various images online of these models show VCC being the middle pin.
They've been working as I had them hooked up, with devices receiving messages successfully. Both orientations work, but there's a difference in duration of an LED lighting up on a receiver.
So, I'm hoping someone with a solid understanding of circuitry can tell me, based on this photo, which pin is VCC and which pin is DATA.
Pin 3 is connected to a 27K resistor then to the rest of the circuit.
If there are no connections on the other side to this pin, this would be the antenna pin.
Vcc should apply significant current for a transmitter to work, if pin 3 was Vcc, 27K would be too large for any range.
IMO.
Thanks a ton for the diagram. Explains the intent nicely.
Guessing the reason both wirings worked is that the correct way uses DATA as the low side transistor switch to sink the current, but switching VCC and DATA means that low side transistor is always saturated with VCC and the signal is driven directly with whatever the DATA pin gives.
So, really not a huge huge deal at all when running at 5v because VCC is same as 5v logic level. Difference being current draw.
Big deal when powering the transmitter at more than 5V, though, probably would've fried that transistor in a hurry with the wrong wiring.
Well I've got some transmitters with an ATAD pin! Now tell me, do your transmitters even have one of those?!
Indeed, they all do.
Actually, though, you can tell from the pic that that particular one is a 315MHz transmitter. The 433MHz one doesn't have that component at the top center, so I'll concede, there are actually 2 designs. Sort of. Same design, just different components mounted.
Is a shame though that data isn't in the middle. I've been using them simply plugged into a Nano's ICSP pins which I've soldered on female headers. Made for a very neat compact package.
LarryD:
You can always cut traces and add jumper wires.
I use little pieces of protoboard for "pinout rewiring" tasks like that. Can put header on either end so it's not permanent that way. Alas I don't have any pictures of an actual wired up adapter like that. I'll have to snap a few pics next time I've got the camera set up.
Try reading the first post that says they are misprinted
"THEY" are NOT misprinted. "THEY" (VCC & GND) are correctly spelled and in the correct location
"IT" (the DATA label) is misprinted because it is the MIRROR IMAGE, like the template was reversed.
2 out of 3 makes "THEY" the majority and CORRECT and IT (DATA pin) the MINORITY and INCORRECT.
They're misprinted. Mine has VCC labelled on pin 3, GND on pin 1, and ATAD is just off to the side.
You should try being less adamant about something you haven't actually seen.
My initial logic being, they simply didn't have space for "ATAD" or "DATA" in between those two there so they just put it off to the side.
And after hooking it up the "wrong" way, it worked, so what could be more reinforcing than something that works?
