Can Someone Explain What All This Stuff Is?

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
Hey all,
I'm looking at the datasheet for the ISP_BLE_5S1057, specifically the AX variant, and when looking at the example they provide I am completely dumfounded by all the extra stuff they have on the schematic. I'm very new to the whole world of PCB design, so if someone could help I would greatly appreciate it!
I've attached a screenshot of what I mean.
Thank you everyone!
Max :)
 

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BobTPH

Joined Jun 5, 2013
9,272
Yes, high frequency RF is not simple, even if you use chips.

Designing a board for that chip is not for beginners because, at those frequencies, layout is critical. I have designed dozens of boards but would not even think of designing one for that chip The manufacturer likely published a reference design. Use it.
 

ronsimpson

Joined Oct 7, 2019
3,212
There is a 32.768 crystal that is the time base for a real time clock.
There is a 32mhz crystal for the computer.
L1 and two capacitors is a filter for 2.4ghz. This connects to the antenna. It is a band pass filter to pass the RF on the right frequency and remove unwanted harmonics, for transmission. It is also used for the receiver as a band pass filter.
L2, L3 and capacitors are to filter the power going to the radio. It removes the noise from the computer on the power.
There are a number of capacitors for power supply filtering.
This IC has several different functions that need to be kept separate.

The PCB layout is difficult.
 

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
Yes, high frequency RF is not simple, even if you use chips.

Designing a board for that chip is not for beginners because, at those frequencies, layout is critical. I have designed dozens of boards but would not even think of designing one for that chip The manufacturer likely published a reference design. Use it.
Hey,
Thank you for your response! Is there an easier way I can use this? I need to connect two devices long rage (<40km) and I'm currently having them connect to the user's phones and have the phones communicate with a server. Is there any way I could do this easier or a better and more beginner friendly IC?
Thank you!
Max :)
 

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
There is a 32.768 crystal that is the time base for a real time clock.
There is a 32mhz crystal for the computer.
L1 and two capacitors is a filter for 2.4ghz. This connects to the antenna. It is a band pass filter to pass the RF on the right frequency and remove unwanted harmonics, for transmission. It is also used for the receiver as a band pass filter.
L2, L3 and capacitors are to filter the power going to the radio. It removes the noise from the computer on the power.
There are a number of capacitors for power supply filtering.
This IC has several different functions that need to be kept separate.

The PCB layout is difficult.
Hey,
Thank you so much for this response!
I just have a couple questions. Are X1 and X2 the crystals for the clock and computer? Also, what does Out_Mod stand for? Are L1, L2 and L3 inductors?
Thank you!
Max
 

MrChips

Joined Oct 2, 2009
31,083
1716499366683.png

What all this stuff?

I see filter capacitors, three inductors and two crystals.
X1 @ 32MHz is the main crystal for the nRF52832 processor.
X2 @ 32.768kHz is a low frequency crystal for a real-time clock or for low power MCU operation.

L1, C3, andC12 is a tuned π-circuit for the RF output.
 

AnalogKid

Joined Aug 1, 2013
11,200
Is there an easier way I can use this? I need to connect two devices long rage (<40km)
Why don't you expand on that, and tell us what it is you are trying to achieve. What devices? connect in what way? Analog signals / digital data / other - ? Unidirectional of bidirectional? Environment - indoors, outdoors, automotive, submerged, high altitude? etc.

ak
 

ronsimpson

Joined Oct 7, 2019
3,212
The IC you are looking is for blue tooth.
I need to connect two devices long rage (<40km)
Blue tooth has different versions. Some of the versions were built for 10m distance and one was built for 100m. This is very short of 40km.
Blue tooth is 2.4ghz frequency which does not work well outdoors.

I have used 900mhz ZigBee Pro and getting long range, but it must be line of sight. It will work with repeaters to get more range.

I am reaching out 5 miles using very good antennas on WiFi at 2.4 or 5ghz. The 2.4 will not work in the rain or on humid days.

Can you get to the internet on both ends? Is cell phone service available?
 
Last edited:

AnalogKid

Joined Aug 1, 2013
11,200
Are L1, L2 and L3 inductors?
Up front, I am not picking on you in any way, but -

If you are asking about the schematic symbol for an inductor, I think a radio that can reach 25 miles reliably is beyond your experience base and skill set. Also. that kind of transmitter power almost certainly will need a license.

ak
 

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
The IC you are looking is for blue tooth.

Blue tooth has different versions. Some of the versions were built for 10m distance and one was built for 100m. This is very short of 40km.
Blue tooth is 2.4ghz frequency which does not work well outdoors.

I have used 900mhz ZigBee Pro and getting long range, but it must be line of sight. It will work with repeaters to get more range.

I am reaching out 5 miles using very good antennas on WiFi at 2.4 or 5ghz. The 2.4 will not work in the rain or on humid days.

Can you get to the internet on both ends? Is cell phone service available?
I'm currently having the devices connect to the phones of the users via bluetooth, then have the phones connect to a server and communicate that way.
 

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
Why don't you expand on that, and tell us what it is you are trying to achieve. What devices? connect in what way? Analog signals / digital data / other - ? Unidirectional of bidirectional? Environment - indoors, outdoors, automotive, submerged, high altitude? etc.

ak
They're two wearable devices that just need to send a bidirectional signal between them, no data or large files. Currently I just want to connect the devices to the phones of the users and then connect the phones through a server.
 

Thread Starter

Max Holdcroft

Joined May 12, 2024
37
No. We don't know what you mean.
Why not create an app that sends SMS from one phone to another phone?
The communication between the two phones isn't the part I'm having trouble with. I'm specifically asking about connecting the device to the phone via bluetooth.
 

AnalogKid

Joined Aug 1, 2013
11,200
Are you talking about a simple status signal, such as press a button here and get an indication over there? Or a sensor detects something here and sends an alert to there? Technically, a bit, but not explicitly computer data related?

ak
 
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