compatibility between NRF51822G2 and NRF51822H0

[User2]

Hello,

I developed a code (softdevice S110 and SDK 10) on a prototype based on a NRF51822G2 chip. I tried to reproduce the prototype with NRF51822H0 chip.

I flashed softdefice and my application but it doesn't work on NRF51822H0 chip (I can see the device with a smartphone but I can't make a connection).

Is it a problem of compatibility?

Best regard

[tesc]

Hi,

According to the nRF51822 IC revision overview nRF51822 QFAAG2 is IC revision 2, nRF51822 QFAAH0 is IC revision 3. Both have the same package and the same Flash and RAM.

It seems strange then, that the revision 2 chip works fine while the revision 3 chip fails, when the nRF51 Series IC revisions compatibility with SDK and SoftDevices document claims the opposite compatibility.

• Was the project started using SDK 10, or is it ported from an earlier version?
• Can you update your question with further descriptions of how connecting fails?

To me it sounds like it may be a timing and/or chrystal issue.

Regards, Terje

[User2]

Thanks for this response, I check the crystal and associate capacitors propoerties.

The capacitors have 5% of tolerance and the requirements seems to be 2% or less.

I tried to test these oscillators :

I use the code posted here : devzone.nordicsemi.com/.../

I have a 16.44 kHz signal.

I measured the clock at the output of the oscillator and I have an voltage offset of + 0,8 V

[tesc]

16.44 kHz is way off, so no wonder why you are unable to set up the connection. BLE applications have a frequency tolerance of 250 ppm on the 32.768 kHz clock, and 32.88 kHz means you are far from that limit.

The 16 MHz should not be a problem, since you do have radio comunication. The problem is the low frequency clock used for the timing between connection events.

You should make sure to use xtals and capacitors of the required tolerance (and required values) for the LFCLK. That would probably completely solve the issue.

[tesc]

Also, check that you select the correct clock source in code. See What low-frequency clock sources can I use? for details. (The question and answer are old, but should still be relevant.)