Nrf2401a Design question

Wireless & IoT
1

I have two design questions concerning the Nrf2401.

The first question is about the PWR_UP pin… My first thought was that the PWR_UP pin should be left unconnected. But after re-reading the data sheet I’m a little worried that leaving it floating may cause some undesired resets. And after looking at the Hi-Res pics in the solder paste tutorial it appears that it is left unconnected but I wanna be sure. So my first question is…

  1. Can I leave the PWR_UP pin unconnected? Or should it be tied to VDD?

I’m not too concerned with conserving power.

My second question is about the Citizen SMD 16mhz crystal for sale in the Spark Fun Store. The data sheet says that two pads are ground pads. But once again the Hi-Res pics show these pads being unconnected.

  1. Should the ground pads be left unconnected?

Thanks for any help!

Oh, yeah Big Up’s to Open Circuits and Spark Fun. That Protel library is awesome.

2

day376:
I have two design questions concerning the Nrf2401.

The first question is about the PWR_UP pin… My first thought was that the PWR_UP pin should be left unconnected. But after re-reading the data sheet I’m a little worried that leaving it floating may cause some undesired resets. And after looking at the Hi-Res pics in the solder paste tutorial it appears that it is left unconnected but I wanna be sure. So my first question is…

  1. Can I leave the PWR_UP pin unconnected? Or should it be tied to VDD?

I’m not too concerned with conserving power.

My second question is about the Citizen SMD 16mhz crystal for sale in the Spark Fun Store. The data sheet says that two pads are ground pads. But once again the Hi-Res pics show these pads being unconnected.

  1. Should the ground pads be left unconnected?

Thanks for any help!

Oh, yeah Big Up’s to Open Circuits and Spark Fun. That Protel library is awesome.

Many crystals don’t have a ground connection, but the case is sometimes grounded as it makes the crystal a bit more stable and can reduce emissions. In many applications it doesn’t matter. I always ground them, myself, if they are present. They also make the crystal more secure.

PWR_UP should be connected to the MCU controlling the device.

Leon

3

Thanks Leon, great reply. I wasn’t sure if it was necessary to route PWR_UP to the MCU ( like on the MIRF). But I’ll route. Once again thanks.

4

you can leave the pwr pin unconnected.

I did and it works fine. Ithink the uMIRF has it connected internally or something like that.

Search for it on the forum because I asked sparky about this before.

5

Thanks Chromatech,

I saw that post or one like it. With it being pulled to VDD through a 100k resistor. Think I 'm gonna bring it out .

Thanks for the heads up though.

6

no sure what you mean by “bring it out”

but sure, you’re welcome.

7

I’ve started writing routines for the MiRF boards. I’ve got a basic range test loop set up now.The examples of data transmission are in “C”. Since I am “C” defficient, does anyone have routines written in PBP for the chip? If not, assembly would be fine.

Thanks,

Ron

8

I don’t have any in PBP.

But really, the C code for MIRF is extremely self explanatory.

If you don’t know any C, it will take you an extra couple of hours of learning it.

You can learn C for PIC using the code provided like the uMIRF code, or the blinking LED code.

Trust me ,its a lot easier programming in C for PIC and uMIRF.