xuezhi Posted August 1 Share Posted August 1 Hi all , I am new to analog discovery but I have watched the tutorial videos. I am trying to see the SPI signal from nrf52840 board When I use the "Protocal" , I can see the data sent When i use the logic analyzer * Trying to see the signal graph , below is what I get But should I get something similar to this ? Link to comment Share on other sites More sharing options...
0 attila Posted August 1 Share Posted August 1 Hi @xuezhi The timing does not look ideal. You should zoom in to see if those spikes are bit or byte transfers... What is the SPI clock frequency ? The Logic Analyze capture rate should be more than double of this. Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 1 Author Share Posted August 1 2 minutes ago, attila said: Hi @xuezhi The timing does not look ideal. You should zoom in to see if those spikes are bit or byte transfers... What is the SPI clock frequency ? The Logic Analyze capture rate should be more than double of this. Thank you for the reply! The frequency is 8M , I will double the capturing rate tmr when I reach the lab. but for the 2nd last line , is actually the clk signal, but it does not look like it, it should not be just spikes , does the capturing frequency affect this? Link to comment Share on other sites More sharing options...
0 attila Posted August 1 Share Posted August 1 3 minutes ago, xuezhi said: The Logic Analyze capture rate should be more than double of this. The Protocol/Spy only stores the relevant bits. The frequency setting is used for data sending and reception glitch filter when this is checked. Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 5 Author Share Posted August 5 On 8/1/2024 at 6:29 PM, attila said: The Protocol/Spy only stores the relevant bits. The frequency setting is used for data sending and reception glitch filter when this is checked. I am using an Adafruit SPI FLASH Breakouts W25Q16 to test my SPI message. When I connect the discovery 2 directly to the nrf52840 development board for SPI connection, i can see the SPI message using Protocol - SPI - Spy When I connect the discovery 2 with the nrf52840 development board together with the W25Q16, I cannot receive any message May I ask if there is any potential reason for this or do I need to change any settings? Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 5 Author Share Posted August 5 Update: The select pin looks very weird to me And when i zoom in to the spike of clk and data (MOSI) I am double checking the code , but it is weird why it can read out the data 0x9Fh and dummy data 0xFFh Link to comment Share on other sites More sharing options...
0 attila Posted August 6 Share Posted August 6 Hi @xuezhi This looks like 0xFF, 0xFF since MOSI is high all the way. Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 7 Author Share Posted August 7 16 hours ago, attila said: Hi @xuezhi This looks like 0xFF, 0xFF since MOSI is high all the way. Yes , I am sending 0x9F 0xFF(Dummy) But my concern 1. Why in this case, my clock signal is not as normal , which should be a up and down square wave? 2. When I connect the discovery 2 directly to the nrf52840 development board for SPI connection, i can see the SPI message using Protocol - SPI - Spy When I connect the discovery 2 with the nrf52840 development board together with the W25Q16, I cannot receive any message Link to comment Share on other sites More sharing options...
0 attila Posted August 7 Share Posted August 7 Hi @xuezhi You should expect the EFBB21 on MISO and not on the MOSI. 1. The slopes indicate sampling points. Increase sampling rate or change Logic Edge option to Vertical if you want to see square transitions. 2. Make sure you have proper ground connection between devices and use the Oscilloscope channels to see the voltages levels, transitions. Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 12 Author Share Posted August 12 On 8/7/2024 at 5:54 PM, attila said: Hi @xuezhi You should expect the EFBB21 on MISO and not on the MOSI. 1. The slopes indicate sampling points. Increase sampling rate or change Logic Edge option to Vertical if you want to see square transitions. 2. Make sure you have proper ground connection between devices and use the Oscilloscope channels to see the voltages levels, transitions. Great Thanks to Attila !!! I manage to capture the message sent from the development board (MOSI) after modifying the options as what you told me but my issue is , this is when the sensor is not powered, I can capture the message sent out. But once the sensor is plugged in, the logic analyzer failed to read . I am not sure if this is because of my code or the connection ( i changed the sensor , cables but still the same ) . Any help or insight is appreciated Link to comment Share on other sites More sharing options...
0 attila Posted August 12 Share Posted August 12 Hi @xuezhi Make sure you are not driving the SPI lines by two controllers, from your devices and AD2/Protocol/SPI/Master On 8/7/2024 at 12:54 PM, attila said: 2. Make sure you have proper ground connection between devices and use the Oscilloscope channels to see the voltages levels, transitions. Link to comment Share on other sites More sharing options...
0 xuezhi Posted August 21 Author Share Posted August 21 On 8/12/2024 at 10:01 PM, attila said: Hi @xuezhi Make sure you are not driving the SPI lines by two controllers, from your devices and AD2/Protocol/SPI/Master Hi attila, thank you for your help!! After a few days of testing and resolder, I think is the poor connection of jumper cable from the sensor to the dev kit Ya but thanks for your help , i manage to understand how to use the analyzer better. Appreciate it!!! attila 1 Link to comment Share on other sites More sharing options...
Question
xuezhi
Hi all , I am new to analog discovery but I have watched the tutorial videos.
I am trying to see the SPI signal from nrf52840 board
When I use the "Protocal" , I can see the data sent
When i use the logic analyzer * Trying to see the signal graph , below is what I get
But should I get something similar to this ?
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