Decoupling Capacitor

have an Arduino Uno and an RFM69HCW breakout board. The datasheet states to have a de-coupling capacitor between the power and ground on the RFM69 chip. The code I’m currently running is failing on the RFM initialize, and I assume that is due to the lack of a decoupled capacitor.

Could someone please help me hook up a de-coupling capacitor to the breadboard so that the power is correctly delivered (a picture would be awesome, or just a basic pin layout to the breadboard)? I’m very new to hardware (I’m a software guy).

I purchased a 100uF Electrolytic decoupling capacitor. I have attached a screenshot of my breadboard. The wires going out from the board go directly to the breakout. Thank you for any help!

Read this:
We see no screenshot.


The datasheet states to have a de-coupling capacitor between the power and ground on the RFM69 chip.

But you don't use the bare CHIP.
You use a breakout board (Adafruit?) with the decoupling caps already fitted.

A 100uF decoupling cap on the supply rail is probably harmless, but should't be needed.
There must be someting else wrong.
Post a diagram and/or picture of your setup.
And the code you're using.

We don't see the screenshot!

low ceramic caps values say 0.01 - 0.1uF for high frequencies per Chip
high electrolytic caps values say about 470uF for low frequencies on power rail

try to keep the leads on your capacitors as short as possible. Even better if you can use surface mounted

Hey guys,

Here's my setup (and the missing screenshot attached to original post).

Arduino Uno R3 (from adafruit)

RFM69HCW Wireless Transceiver - 915MHz (from Sparkfun)

I've tried code from two different libraries - RadioHead and LowerPowerLab. I think I like the RadioHead one better since it appears to be more up-to-date. The code uses the default constructor from both libraries and just does a simple transmit. The RadioHead library says "init failed" when trying to initialize the library and the LPL code simply resets the device when calling initialize().

I also have an Arduino Feather with the same module, and the same code appears to be working (with some different parameters passed into the RFM69 constructor).

Thank you so much for the fast responses! I am sure I have a complete misunderstanding of how to move power from the Arduino through the capacitor.