Ok heres my problem. Ive got a set of HT12d/HT12e coders Im using with a RF project. The RF modules are MKR5-434-5-50 transmitters and recievers from RFSolutions, 433 Mhz 50 kpbs data rate. Ive assembled both boards on PCBs. To test them Ive got a 12F675 pusling every quarter second into one of the encoders data lines, I tied the transmit enable pin to ground for constant transmission. With this arrangment the decoders should blink a led on the data line the 675 is pulsing on.
After setting it all up I still get on lights on the data lines of the decoder(or voltage, checked them all and hovers around 1.1 volts) but the reciever has a signal strength indicator. When the transmitters off I get 1.6 volts like it should but after powering up the transmitter boards the SSI goes to 2.5 to 2.6 volts as it should when a signal is detected. This leads me to believe that the reciever is getting data from the transmitter but either the coders are dropping the ball(corrupted) or the coders are flat out not functioning. So I tested the coders by tying their data pins together, after doing so the decoders 17th pin closed(pin 17 is a transmit detected NO relay) which would indicate that they are capable of communicating. Just to double check I made sure I could get a signal on each data pin on the reciever by bringing them all low one by one on the transmitter, which they did.
Anyhow it has been suggested to me that the ht12 series may not be quick enough for my application. I assumed that aslong as the encoders/decoders opperated slower then the transmitters bit rate(50 kbps in this instance) that everything would be A-ok.
Details of my project.
Project will use 1 transmitter to communicated between 3 remote reciever stations. Maximum range will not exceed 800 meters but will typically be close to this maximum range during normal operation. The transmitter will send 1 of 16 possible codes and the recievers will all recieve and act accordingly to predefined conditions programmed into them via 16F84A's.
Schematic I followed **broken link removed** (towards bottom)
reciever data sheet
**broken link removed**
transmitter data sheet
**broken link removed**
My pbc layout is enclosed
Any help or suggestions will be greatly appreciated.
After setting it all up I still get on lights on the data lines of the decoder(or voltage, checked them all and hovers around 1.1 volts) but the reciever has a signal strength indicator. When the transmitters off I get 1.6 volts like it should but after powering up the transmitter boards the SSI goes to 2.5 to 2.6 volts as it should when a signal is detected. This leads me to believe that the reciever is getting data from the transmitter but either the coders are dropping the ball(corrupted) or the coders are flat out not functioning. So I tested the coders by tying their data pins together, after doing so the decoders 17th pin closed(pin 17 is a transmit detected NO relay) which would indicate that they are capable of communicating. Just to double check I made sure I could get a signal on each data pin on the reciever by bringing them all low one by one on the transmitter, which they did.
Anyhow it has been suggested to me that the ht12 series may not be quick enough for my application. I assumed that aslong as the encoders/decoders opperated slower then the transmitters bit rate(50 kbps in this instance) that everything would be A-ok.
Details of my project.
Project will use 1 transmitter to communicated between 3 remote reciever stations. Maximum range will not exceed 800 meters but will typically be close to this maximum range during normal operation. The transmitter will send 1 of 16 possible codes and the recievers will all recieve and act accordingly to predefined conditions programmed into them via 16F84A's.
Schematic I followed **broken link removed** (towards bottom)
reciever data sheet
**broken link removed**
transmitter data sheet
**broken link removed**
My pbc layout is enclosed
Any help or suggestions will be greatly appreciated.
