Saturday, September 28, 2013

u_nRFv2 board

I just finished designing this new board this week, version 2 of my micro-nRF board:

As I'm writing this now, I realize that I never wrote a post about the first micro nRF board. You may have seen pictures of them in previous posts like my first LED glasses. The original board was intended to be a general-purpose wireless board, using a PIC16F1824 and nRF24L01+. I designed in the SOIC version of the PIC because I have lots of them lying around because they're used in a product at work, but I later regretted this decision because of the size. I also frequently ran into issues with the lack of I/O available--the PIC has 12 I/O, the radio uses 6 and an LED uses a 7th, so there's not much left for the application.

I designed version 2 to be smaller and to include more I/O. This version uses the PIC16F1829 in the QFN package. I got rid of the trace antenna because I usually use wire whips, and it's not worth paying for PCB space that only has a wire. The overall board is smaller than the nRF24L01 radio modules I buy from eBay (this is still the cheapest way to get all the radio components--I just transplant the chip and all the passives onto my board [except the crystal, I had to reduce to a smaller package for v2]). The 1829 has 18 I/O which leaves me 11 available for the application. I still included the LED indicator, and I connected one pin to an N-channel MOSFET on the board.

This board is my first order from oshpark, which looks like it will be awesome. My boards went to fab yesterday, we'll see how they turn out. Here's the schematic:

I wrote a software template to use these boards that gets the radio running in either transmit or receive mode, here it is.


  1. Nice! I saw your glasses at MASTERs 2013 and they were great!

  2. Any particular reason you don't just use nRF24LE1 for the µC?