Single-Board Universal Module

I finally got around to assembling my 9.4 board, and it seems to work OK after I sorted out the DC/DC, which was quite a piece of work. All radio chips (except for the CC2500, which doesn't have a crystal yet) are recognized, but I have no idea if the RF part is working correctly.

This may seem like a stupid question, but how do you actually set it up in hardware.ini?

Edit:

Never mind, I figured it out. For anyone crazy enough to try this at home, here is what you do:

1. You have to use the code from the "universaltx" branch of the git repo. There will be a few minor build errors to fix, shouldn't be a big deal.
2. Build the "utx_devo" target from the "universaltx" directory and install it on the universaltx via USB with the st-link dfuse tool.
3. Build and install deviation for your desired target.
4. Edit the modules section of hardware.ini to look like this:
[modules]
enable-multimodctl=B11
enable-multimod=B12
enable-cyrf6936=S0
has_pa-cyrf6936=1
enable-a7105=S1
has_pa-a7105=1
enable-cc2500=S2
has_pa-cc2500=1
enable-nrf24l01=S3
has_pa-nrf24l01=1

I've only tested the nRF24 chip so far, but I'll try to test all RF chips tonight.

This has really been a fun project. Sure, reworking a board tightly packed with 0402 passives and qfn chips wouldn't be considered fun by most people, but with the right tools and techniques it's not that bad either. I'd like to thank PB and all the others who did all the heavy lifting on this project, so that someone less experienced like me was able to replicate it. Even though this is obsoleted by those Chinese 4 in 1 modules, and this thread has become hard to follow at times, it was still a great learning experience. So thank you all for your great work!!

Hi alibenpeng,

Thanks for your sharing. I think I'm one of those crazy enough and almost completed building 3 pieces of this board. It was my laziness that I took 4 months to bought every components and tools, and started my very first hot air solder paste soldering from eight months ago, but now still yet to solder all the chips, worried about causing them thermal or static deaths. Though I will soon complete them all.

I think I like this design more than those Chinese 4 in 1 modules as it uses software controlled static switch among the 4 different radios, which is so convenient.

While I 'm still in the progress, with my noobness I'm interested in any of your experience in building your boards, especially on what you mentioned about a DC/DC problem. Would you like to share a bit more on this of your experience?

Thanks,
err888

4 months is what you call lazy? How about 1.5 years?

Regarding the DC/DC regulator:

This one was a tricky beast to solder by hand because of the big thermal pad underneath. It took me quite some time to get it right, that's all. There obviously can't be any shorts or opens, or it won't work at all.

Another thing I'm having problems with is getting all the radios to work. All of them seem to respond via SPI (at least I'm not getting any "Module not found" errors any more), but only the NRF24 will bind to a receiver. As I don't have any proper instruments that would work on 2.4GHz, I made a makeshift spectrum analyzer with an RTLSDR dongle and a 2.4GHz downconverter for sattelite TV. I can then use gqrx (SDR# for linux) to at least confirrm the presence (or absence) of RF on the antenna.

soldering a part with a ground pad would require a hot air tool, contact soldering will not work. For single sided board there it is possible to use a hot-plate that will preheat the board making soldering much easier. Using actual solder paste will also be necessary.
RFexplorer is a low cost spectrum analyzer that can be used for projects like this.

PhracturedBlue wrote: I think SEEED is $40 + shipping for 10 4-layer 5x5 boards (we can only fit one universaltx per board)
OshPark is ~$25 for 3 boards including shipping
More importantly ,we designed to the OshPark design rules, which means the boards are likely to actually work

And the footprint for the PE part is the same as the Sky13384 though the pin-out is different

Seeed PCB is very cheap now, $10 without shipping for 10 copies of a 10cm x 10cm board!!

Is it for 4-layer board?

www.seeedstudio.com/fusion_pcb.html

4 layers 100x100mm, 1 oz. , 6/6 mil, 0.3mm holes min, HASL, $49.95 USD. FR-4, 6-8 days, plus shipping, typ ~ $20.
I have used them for many projects, so far all OK.
You can adding scoring for snapping boards apart, for arrays, at no extra charge.
The "5x5" board would then fit four one each 100x100mm, 40 boards for ~ $70, or $1.75/ ea.
I prefer ENIG, for a flatter surface and better storage life. not much more.
You do not have to stick to the 100x100mm format, pricing does not snap for larger sizes. so add your frames for your arrays, and also order STENCIL at good price.
They also offer assembly, plus they can market the stuff for you.