- Wed Mar 22, 2017 5:29 pm
#194027
I have purchased an RFM69HCW breakout board (WRL-12775) from sparkfun and I would like to use it with one of uno's (an Uno or a Redboard). The rfm69 runs at 3.3volts and the uno's at 5volts.
Reading the tutorial for the breakout, I saw that sparkfun's bi-directional logic level converter (BOB-12009) was recommended for handling the 3.3v -5v discrepancy. I purchased one of those and hooked up the radio to the arduino following the tutorial ( rfm69hcw-hookup-guide).
The wiring diagram runs the MOSI, MISO, CLOCK and SLAVE SELECT through the level converter, but it runs the interrupt direct to digital pin2 on the redboard/uno. Here's a link to the fritzing diagram of the circuit:
https://cdn.sparkfun.com/assets/f/1/0/e ... dboard.png
Could/would somebody please explain why that's OK and works? I've read a bunch of articles and tutorials on the board and spi and I can't seem grasp why the interrupt can connect straight to the uno without risking being fried or not being understood. Without this understanding I'm afraid of frying my radio board and that would be a drag since I have managed to get it to read the wireless signal from my Davis weather station using a couple of libraries over on github. My hope is somehow glom the circuit onto a router with openWRT on it and from there to push it to weather underground and a separate personal weather station page.
Sincerely,
Hawley
Reading the tutorial for the breakout, I saw that sparkfun's bi-directional logic level converter (BOB-12009) was recommended for handling the 3.3v -5v discrepancy. I purchased one of those and hooked up the radio to the arduino following the tutorial ( rfm69hcw-hookup-guide).
The wiring diagram runs the MOSI, MISO, CLOCK and SLAVE SELECT through the level converter, but it runs the interrupt direct to digital pin2 on the redboard/uno. Here's a link to the fritzing diagram of the circuit:
https://cdn.sparkfun.com/assets/f/1/0/e ... dboard.png
Could/would somebody please explain why that's OK and works? I've read a bunch of articles and tutorials on the board and spi and I can't seem grasp why the interrupt can connect straight to the uno without risking being fried or not being understood. Without this understanding I'm afraid of frying my radio board and that would be a drag since I have managed to get it to read the wireless signal from my Davis weather station using a couple of libraries over on github. My hope is somehow glom the circuit onto a router with openWRT on it and from there to push it to weather underground and a separate personal weather station page.
Sincerely,
Hawley