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Topic: [solved] Some advice please... (Read 2433 times)
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G4KCM
Neuling
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Posts: 24
 
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[solved] Some advice please...
« on: 01. July 2018, 12:34:23 »
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Hi,
I am hoping that someone can give me a little support with an issue I am experiencing.
My OVI40 was built using an H7 processor and worked fine using some test code from Danillo. As it seemed to me that the current release of the H7 had some problems which would not be easily resolved and I decided to revert to the F7.
Removing the H7 and installing the F7 went without any problem using a hot air desoldering station. Programming via DFU and ST-Link of the boot loader and main firmware both work fine (I tried both ways out of desperation) but upon power up all that I get is a white screen with no activity detectable on any i/o. I have thoroughly cleaned residual flux and both visually and electrically checked the connections to the processor and all appears fine the only thing that appears to be not working is the 32,768Hz crystal oscillator. Usually I find with this type of oscillator despite the additional load of a 10x probe some activity is detectable with an oscilloscope but I have seen nothing. I tried some different capacitors and crystals but still nothing.
My question to those familiar with the boot loader and firmware is will a non functioning LSE oscillator make the boot loader hang and cause a white screen? I have seen mention in other posts that make me think it will but it is a bit unclear to me if it refers to the main firmware or both the boot loader and the main firmware.
I am not familiar with the internals of the STM32 devices but looking at the copious amount of documentation it appears that the LSERDY flag is in a RCC_BDCR register at 0x40023870. Reading this with ST-Link shows the status bits associated with the LSE clock are all unset. I must though add that this is my first dive into STM32 internals and whilst I have learnt a lot I may be looking in completely the wrong place due to my misinterpretation of the data :-) Hence I would appreciate some confirmation of the impact of a non-function LSE oscillator on the boot loader from someone more experienced before I try more crystals and capacitors.
Thank you in anticipation.
Clive, G4KCM
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| « Last Edit: 14. July 2018, 09:37:32 by DL8EBD » |
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G4KCM
Neuling
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Posts: 24
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Re:Some advice please...
« Reply #2 on: 01. July 2018, 16:41:25 »
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Thank you Andreas. That’s exactly what I needed to know.
Best 73
Clive
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G4KCM
Neuling
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Re:Some advice please...
« Reply #3 on: 14. July 2018, 08:02:15 »
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Just to close this thread out.
After looking at the STM specs in AN2867 I found a crystal designed for a 6pF load that matched the STM spec and after fitting that all worked just fine. Initial timing checks are good which indicate that all is well matched.
73, Clive
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G4KCM
Neuling
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Posts: 24
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Re:[solved] Some advice please...
« Reply #5 on: 14. July 2018, 11:55:28 »
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Thanks Andreas and all noted regarding how to close out. I’m thinking that I might use the H7 on another UI board as I have the majority of components to hand. So when The RF side becomes available I will get another UI & display board shipped at the same time.
Best regards and my thanks again to you and the team for your continued efforts.
Best 73, Clive
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