What kind of capacitor is need for the NRF24L01+


  • Hardware Contributor

    Hey guys, I am using the NRF for my MySensors network and I am always adding a capacitor as it is suggested in the "Build" part of this site. What I was wondering about though: I am using mostly SMD components so the pcbs get very small and flat but then I have to add this huge capacitor (in comparison). For the atmega you can use small 100nF 0806 smd capacitors, so I was wondering what kind of caps do you need for the NRF? Does it have to be an electrolytic capacitor, are there any small (outer size) caps that you could use?


  • Hardware Contributor

    it depends on your power supply (if you need filtering, the battery used etc..) but for buffer storage, i think 10uF may be a good start for NRF. for my rfm, i use 10 to 100uF, it depends. i use ceramic cap for less leakage.



  • I used two capacitors in parallel with big capacities, just to be sure here is no problem with power: electrolytic of 100uF + ceramic 470nF, presented here: https://www.openhardware.io/view/55 in the third picture.
    For a smaller module, I think you can add a ceramic of 100nF to filter higher frequencies and a tantal or even electrolytic of 10uF, if you choose lowest voltage for them they should be smaller.


  • Hardware Contributor

    I use 10µF for the radio and 100µF as reserve when using a CR2032. Ceramic or tantalum.
    I use 1206 which is a "big" size for SMD but there's no comparison with the size of the electrolytic caps.
    Here a 10µF ceramic for the radio and a 100µF tantalum for reserve, next to a CR2032 holder which is much thicker, so I don't really need to use smaller SMD size.
    0_1483726560676_IMAG1262.jpg



  • I usually use 10uF/16v electrolitic if space permits. However last time I tried pro mini's non used raw regulator 10uF smd tantalum which I soldered directly on nrf pins and it works perfectly. Due to size and ease of use I guess I'll order some smd tantals.


  • Hardware Contributor

    Nice, thanks guys!
    Btw as I am using CR2032 battries very often lately... do you adda cap in parallel? If so which size? I see that @Nca78 is using one but I read different optionions: some say it helps (espacially with the radio drawing huge amounts in a short time), others say it impacts the battery usage time too much...


  • Hardware Contributor

    You cannot skip the capacitor when using a radio with a CR2032.
    Just use a good quality ceramic one to limit the losses.


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