Go Down

Topic: level shifting using CD4050BE (Read 11872 times) previous topic - next topic

raschemmel

Quote
Why is SDN connected through the level-shifter and instead of directly connecting it to GND?
SDN ? (what is SDN? there is no such pin)

Which IC ?

Which pin ?

Paul__B

#16
Apr 26, 2016, 12:43 am Last Edit: Apr 26, 2016, 12:47 am by Paul__B
Why is SDN connected through the level-shifter and instead of directly connecting it to GND and why is the CD4050BE grounded through the Si4432? (Why that funny chaining and why not connect GND/SDN of the Si4432 and VSS of the CD4050BE directly to GND of the Arduino?)
Ah!  Not my diagram of course (and I omitted to link the source) and I did not notice that.  Just an error in the drawing.  All grounds would be connected and I cannot imagine it matters whether SDN is connected via the level shifter or directly to ground.

SDN ? (what is SDN? there is no such pin)
Get your magnifier out!

Addendum: Pin 20; "Shutdown" - low to operate the chip.

raschemmel

That is one complicated datasheet !

wothke

I just received the IC and it works like a charm.. (being aware now that some people in here are interrested in the results, here a link to my respective project: https://jwothke.wordpress.com/2016/05/08/and-now-to-something-completely-different/ ;-) )


wothke

Is it this ?
no

at first I had used  [this but I found it rather time consuming to solder the 1.27mm pin header, so when one of those died I replaced them with
this, but when I killed one of those too I decided that I should look for something with a 2.54mm header and since I thought that a somewhat better antenna might not be a bad thing I am now using that one

raschemmel

Where is the receiver and is there more than one ?

How did you learn to use tge chip ? (it is unusual for newbies to post about a project that has a chip with such a detailed datasheet and not ask for help with the datasheet. What's your electronics background ?

wothke

#22
May 10, 2016, 11:54 am Last Edit: May 10, 2016, 02:28 pm by wothke
Where is the receiver and is there more than one ?

How did you learn to use tge chip ? (it is unusual for newbies to post about a project that has a chip with such a detailed datasheet and not ask for help with the datasheet. What's your electronics background ?
I am using both - a SI4432 based transceiver and an additional 433mHz receiver (see one of these). When you look at the photo on my project page you'll see the blue transceiver PCB just below the externally mounted antenna. You'll not see the 433mHz receiver since it is glued beneath the CB that holds the Arduino.. (I am using the SI4432 to communicate with my PC whereas the 433mHz receiver picks up the signals of the nearby soil/air sensors..)

I have virtually no electronics background at all (as a kid I had one of those electronics experimentation kits and later I did simple repairs like replacing exploded electrolytic capacitors on my PC's mainboard to give it a 2nd life.. but that's it). I never read the SI4432 datasheet.. but I had found a youtube video where some russian guy shows how to wire it to an Ardiuno.

raschemmel

#23
May 10, 2016, 02:48 pm Last Edit: May 10, 2016, 03:22 pm by raschemmel
I must say, you should probably get the award for "Most Motivated and Determined Newbie".

I had a hard time beleiving a Newbie could read and undrrstand that such a detailed datasheet. It would probably take at leasf an hour to study it and undrrstand it. I'x like to see the link about "Russian Guy" ..

What about the code ? How did do that ?

You should post it so others can see it. You can post it using the CODE TAGS [</>] button or as an attachment.

wothke

#24
May 10, 2016, 03:53 pm Last Edit: May 10, 2016, 04:12 pm by wothke
I must say, you should probably get the award for "Most Motivated and Determined Newbie".
LOL

...I'x like to see the link about "Russian Guy" ..

What about the code ? How did do that ?

You should post it so others can see it. You can post it using the CODE TAGS [</>] button or as an attachment.
I think this is the video... and eventhough the russian language is total gibberish to me.. the guy shows schematics (now that I see it again I realize that he even already used a CD4050BE.. and unfortunately I had missed that one) and you see the example code he is using..

Well this is the summary that I wrote up for myself:

Code: [Select]
*  color:     transciver pin:       comment:                arduino pin:
*  -----------------------------------------------------------------------
*  black              GND+SND                                 GND
*  yellow           nIRQ/NIRQ                                 D2
*  green            nSel/NSEL      chip select/ss             D10
*  white             SCK/SCLK      spi clock in/sck           D13
*  blue                   SDI      spi data in/MOSI           D11
*  purple                 SDO      spi data out/MOSO          D12
*  red                    VCC      3.3V                       separate regulator may be required (e.g. 3.3V on ProMini is limited to 50mA)!
*                        GPIO      unused


As for the code you can then use the out of the box "RF22" lib examples (e.g. "rf22_client") or the respective rf22 examples from the more recent RadioHead lib (I am using the older "RF22" lib because it consumes slightly less FLASH memory - and I am very short on FLASH memory: "Sketch uses 30,416 bytes (99%) of program storage space.").

Depending on the library version that you use you might just need to define:
Code: [Select]

#define SLAVE_SELECT_PIN 10
#define USE_IRQ 0    /* Arduino PIN is USE_IRQ+2*/


and since the device requires 3.3V you may need to add some 5V to 3.3V level shifting depending on the Arduino you use..

raschemmel

#25
May 10, 2016, 06:12 pm Last Edit: May 10, 2016, 06:14 pm by raschemmel
Your schematic doesn't show the 30 MHz crystal but the datasheet shows it the application examples .
Do you have one ?

Looking at the schematic you posted it is clear it is simply a SPI interface with d2 driving the Si4432 Nirq pin.

The datasheet has application schematics that include many components not in yours.

How much is actually missing from your schematic ?

wothke

What "schematic" and what "datasheet" are you referring to? My transceiver looks exactly like the one that the aliexpress seller depicted in the link that I had posted above. The respective pin layout is this:



I have no idea what crystals (or other building blocks) it may or may not have.. for me it is just a black-box that I can access using some SPI interface :-)

raschemmel

It looks like the crystal is the rectangular metal thing near the chip.


Go Up