I'm developing one nice application on BlueNRG-1 chip. I'm facing one issue with some of my boards. I have checked out all possibilities. But problem seems to be with some BlueNRG-1 chips or It gets damaged internally after hand soldering. Not Sure! Please problem details below.
I have recorded my Laptop screen as well. Please see this link: BlueNRG-1 Chip ST-link Connectivity Issue - YouTube
|Overview: Application having simple 16x7 matrix LED display which is drive from ULN2004 & 74HC595 shift register. UL2004 connected directly through controller's IO and shift registers are connected via SPI of controller. Application should work on 12V supply. So there are 5.0 & 3.3V regulator. Shift register 595 chip having 5V & 3.3V provision via 0E resistor. One source at a time possible.|
1) Display suddenly stops working properly. Appearance of problem is very random.
2) ST-link stop communicating.Sometime it connect when power recycled & automatic mode in use. This problem associate with 1st problem. This problem appear whenever first problem start appearing.
3) Few boards never have this problem but few other boards constantly having this problem.
1) BlueNRG-1 ST-link utility V1.0.0 is in use.
2)Keil IDE is in use.
3) All peripheral driver taken from ST's website.
4) Referring BlueNRG-1 DK 2.3.0
5) Controller, Balun & 16MHz Crystal arranged from Digikey
6) Other components arranged locally from lamington road mumbai.
7) Using ST-link/V2 debugger
8) 8 boards made.
9) Design reference taken from ST
1. Display sometimes works sometimes not. This patterns repeats. Some time display goes completely off.
2. Data comes on row properly which is connected via ULN2004 to controller port.
3. Columns stops running in expected pattern. Columns are connected via 595.
4. some hardware working fine but is some hardware observing this error.
5. When this problem comes controller stop communicating with BlueNrg -1 ST link.
|Test Cases and Result|
|Sr. No.||Test Cases||Result|
|1||Controller Ground connection resolved in new PCB version||Microncontroller Ground connection is proper now.|
|2||74HC595 chips replaced with new ones||Problem still exist|
|3||74HC595 VCC change to 3.3V||Problem still exist|
|4||74HC595 VCC change to 5.0V||Problem still exist but other board continuously working on same situation.|
|5||Power level 3.3V and 5.0V checked||Both level was 99% correct. Problem exist|
|6||Touch up done to ensure connectivity||No continuity issue|
|7||Possiblity checked in firmware. But everthing is alright.||Problem doesn't seems to related with coding otherwise other hardware shoudn't worked properly.|
|8||Hardware properly checked||Everything components and connections are correct.|
|9||595 chips also exchanged from working board.||Problem still exist. Problem doesn't seems to be with 595 chips|
|10||ST-link connection checked||other board connecting properly but this board sometime connect sometime doesn't. 90% of time doesn't connect. Sometime connect when power recycled and when keep in automatic mode.|
|Possible Causes and Comment|
|Sr. No.||Possible Causes||Comment|
|1||Hardware Design Issue||Not possible as other hardware is working properly on same design and having same PCB version|
|2||Coding Issue||Not possible as other hardware is working properly on same code.|
|3||PCB Manufacturing Issue||Not possible because PCB manufacturer is proto specialist. Its very rare they have given faulty PCB. Also problem is not static its random. So this should not be the issue.|
|4||Soldering Issue||Touch up already done and properly checked. Everything looks fine.|
|5||Fault or errata within controller||As this is new series and launched in recent year. Possibility is there. But ST would have tested very properly.|
|6||Noise Issue||If noise issue then atleast once problem should come in other working hardware.|
|7||power supply Issue||Power supply is proper. This should not be the issue.|
|8||Hand soldering setup||Temperature was max 350°C which is against the recommendation of datasheet. But other hardware made with same setup. So can't say.|