The high frequency 32MHz crystal is calibrated through capacitor feet to ground, and plays a role in accurate radio transception.
Steps to reproduce
Refer to the schematic
Use a frequency counter
Measure the crystal circuit
Expected result
The output of the HSE crystal is as expected.
Actual result
HSE crystal output is unknown pending finding a suitable measurement tool.
Proposed method
Initiate a CW tone from SAMR34 with the help of Radio utility tool
SAMR34_SiP_Reference_Design_Package_V2.0/2. SAMR34_Reference_Design_Package/5. Radio Utility
Measure the frequency of the generated CW tone
Reduce the measured error between the measured frequency and the selected frequency
This could be done by tuning the external load capacitors of the crystal
Severity level
This is low priority because project requirements do not mandate calibration or radio service quality.
# Test HSE crystal circuit for best practice
## Problem environment
The high frequency 32MHz crystal is calibrated through capacitor feet to ground, and plays a role in accurate radio transception.
## Steps to reproduce
1. Refer to the schematic
1. Use a frequency counter
1. Measure the crystal circuit
## Expected result
The output of the HSE crystal is as expected.
## Actual result
HSE crystal output is unknown pending finding a suitable measurement tool.
## Proposed method
1. Initiate a CW tone from SAMR34 with the help of Radio utility tool
1. SAMR34_SiP_Reference_Design_Package_V2.0/2. SAMR34_Reference_Design_Package/5. Radio Utility
1. Measure the frequency of the generated CW tone
1. Reduce the measured error between the measured frequency and the selected frequency
1. This could be done by tuning the external load capacitors of the crystal
## Severity level
This is **low priority** because project requirements do not mandate calibration or radio service quality.
Frequency and capacitance was measured and correlated using a frequency counter, realtime oscilloscope, differential probes, and a spectrum analyser. It seems the HSE is much less sensitive and susceptible to interference compared with the LSE. The target frequencies (of both HSE and signal from SX1276) are obtained with 18pF load capacitors, as well as 12pF, 15pF, and 22pF substitutions.
Frequency and capacitance was measured and correlated using a frequency counter, realtime oscilloscope, differential probes, and a spectrum analyser. It seems the HSE is much less sensitive and susceptible to interference compared with the LSE. The target frequencies (of both HSE and signal from SX1276) are obtained with 18pF load capacitors, as well as 12pF, 15pF, and 22pF substitutions.
Test HSE crystal circuit for best practice
Problem environment
The high frequency 32MHz crystal is calibrated through capacitor feet to ground, and plays a role in accurate radio transception.
Steps to reproduce
Expected result
The output of the HSE crystal is as expected.
Actual result
HSE crystal output is unknown pending finding a suitable measurement tool.
Proposed method
Severity level
This is low priority because project requirements do not mandate calibration or radio service quality.
Frequency and capacitance was measured and correlated using a frequency counter, realtime oscilloscope, differential probes, and a spectrum analyser. It seems the HSE is much less sensitive and susceptible to interference compared with the LSE. The target frequencies (of both HSE and signal from SX1276) are obtained with 18pF load capacitors, as well as 12pF, 15pF, and 22pF substitutions.
Solved in
4e84baeand8819d77.