Jump to content
43oh

New MSP430 Wireless Sensor Node


Recommended Posts

  • Replies 62
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

I've wanted to create a batteries included, very low cost wireless sensor kit for quite a long time now.  I've made some attempts in the past but up until this point they were either too expensive to

Well boards have arrived and I started building them up. So far I have 2 of them built up and tested.   Now the real work begins in writing Energia libraries!             One chang

Status update: I now have 6 units built and tested. The enrf24 library has also now been updated to support RF75 and I've tested over the air compatibility with nRF24 based nodes     I made th

Posted Images

you mean uscia? (uart is on uscia)

Yeah I'm mistaken on the name. Didn't bother to look it up. I usually simplify it in my mind that there is the port with the UART and then "the other port."

 

 

Sent from my iPhone using Tapatalk

Link to post
Share on other sites

Sorry for my ignorance, I want to write 32 bytes out of the SPI port can I load up a fifo and tell the peripheral go or do I need to load each byte into the register to shift out.

 

If the latter, I don't see as much advantage over bit banging.

 

 

Sent from my iPhone using Tapatalk

Link to post
Share on other sites

Sorry for my ignorance, I want to write 32 bytes out of the SPI port can I load up a fifo and tell the peripheral go or do I need to load each byte into the register to shift out.

 

If the latter, I don't see as much advantage over bit banging.

 

 

Sent from my iPhone using Tapatalk

It's the latter.  The SPI peripheral can still pump out the bits faster than bit-banging IIRC.

Link to post
Share on other sites

It's the latter. The SPI peripheral can still pump out the bits faster than bit-banging IIRC.

I would have to think about that, the Transceiver can work up to 8MHz and the CPU is running at 16MHz. My instinct tells me that I can get close if not interrupted. I'll need to test it out I guess.

 

 

Sent from my iPhone using Tapatalk

Link to post
Share on other sites

My initial reaction is that it will come at a cost of energy usage as you're using CPU cycles instead of a peripheral - plus I don't believe the NRF library I use supports bit-bang.  Unfortunately I don't know enough to answer how big of an impact it might have to battery life, if in fact that's valid.

Link to post
Share on other sites

My initial reaction is that it will come at a cost of energy usage as you're using CPU cycles instead of a peripheral - plus I don't believe the NRF library I use supports bit-bang. Unfortunately I don't know enough to answer how big of an impact it might have to battery life, if in fact that's valid.

I'll run some tests but I'm thinking that the impact won't be that much different because the CPU must stay active to feed bytes inti the peripheral anyway. The biggest tradeoff would be the performance hit that you are spending cycles shifting out bits instead of doing other computation.

 

 

Sent from my iPhone using Tapatalk

Link to post
Share on other sites

I'll run some tests but I'm thinking that the impact won't be that much different because the CPU must stay active to feed bytes inti the peripheral anyway. The biggest tradeoff would be the performance hit that you are spending cycles shifting out bits instead of doing other computation.

 

 

Sent from my iPhone using Tapatalk

Right - that's what I would expect to make an impact.  I typically drop into LPM (2 I think?) while the peripheral is shifting bits.  

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...