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by John Westlake
Fri Aug 24, 2018 7:18 am
Forum: Compute Module
Topic: Commercial projects / products using Rpi CM3
Replies: 2
Views: 1521

Commercial projects / products using Rpi CM3

I just wanted to proudly post our Network Audio streamer using the Rpi CM3 having just won the EISA Best Product award :) https://www.eisa.eu/awards/pro-ject-stream-box-s2-ultra/ Proud to be a part of the expanding Rpi "World" - leveraging the enthusiasts and professional alike :) Just goes to show ...
by John Westlake
Mon Aug 06, 2018 9:20 pm
Forum: Compute Module
Topic: CM3 eMMC boot delay
Replies: 4
Views: 894

Re: CM3 eMMC boot delay

MWPau wrote:
Sun Aug 05, 2018 3:15 pm
A 2.2k pull up to 3.3v seems to have done the trick.

Is there a recommended resistor value that should be used for this?

Thanks!
If HDMI is not used, then 2K2 is OK, we use 10K...
by John Westlake
Sun Aug 05, 2018 1:33 pm
Forum: Compute Module
Topic: CM3 eMMC boot delay
Replies: 4
Views: 894

Re: CM3 eMMC boot delay

A common issue for first time CM3 hardware developers - I'm betting you missed a pull-up resistor on the HDMI_SDA line :)

See this Thread:-

viewtopic.php?f=98&t=115095
by John Westlake
Mon Jul 30, 2018 2:50 pm
Forum: Compute Module
Topic: Compute Module 3 Thermal Information
Replies: 4
Views: 986

Re: Compute Module 3 Thermal Information

gsh wrote:
Mon Jul 30, 2018 10:06 am
We're still writing up results
Thank you for the update.
by John Westlake
Sun Jul 29, 2018 11:27 pm
Forum: Compute Module
Topic: Compute Module 3 Thermal Information
Replies: 4
Views: 986

Re: Compute Module 3 Thermal Information

I asked the question awhile back about the specific junction-case thermal resistance for the BCM2837 but sadly got no reply :(
by John Westlake
Sun Jul 29, 2018 6:32 pm
Forum: Compute Module
Topic: Troubleshooting CM3/CM3L custom PCB
Replies: 6
Views: 984

Re: Troubleshooting CM3/CM3L custom PCB

Non come to mind, but just watch CPU throttling due to overheat - IMO the CM3 REALLY requires a heatsink. IMO, the CM3 is unusable without a heatsink - even unpacking an OS install can trigger thermal throttling... Don't fall into the trap as we did that that as a heatsink is not required for the RP...
by John Westlake
Sat Jul 28, 2018 1:43 pm
Forum: Compute Module
Topic: Troubleshooting CM3/CM3L custom PCB
Replies: 6
Views: 984

Re: Troubleshooting CM3/CM3L custom PCB

Here's another question, it seems to take a significant amount of time for the system to boot on my PCB vs the IO board. Is there anything in particular that could cause this from a hardware perspective? A common issue for first time CM3 hardware developers - I'm betting you missed a pull-up resist...
by John Westlake
Sat Jul 14, 2018 2:45 am
Forum: Compute Module
Topic: Can CM3 be used as CM3L by removing the EMMC
Replies: 7
Views: 1901

Re: Can CM3 be used as CM3L by removing the EMMC

thank you, I read the schametic and short R12 R16 R17 R18 R19 R25 , disconnect R24 , but the pi still can not boot To convert a CM3 to CM3Lite* ("Read note about SDX_VREF limitation):- Move R10 to R9 (0R) Move R24 to R25 (33R) Add R9, R12, R16, R17, R18, R19 (0R) As the onboard eMMC is still connec...
by John Westlake
Mon Jul 09, 2018 1:32 pm
Forum: Compute Module
Topic: Integrating BCM43438-based SDIO WiFi Module on CM3
Replies: 6
Views: 6063

Re: Integrating BCM43438-based SDIO WiFi Module on CM3

Hows it going - have you made any progress? we are also considering implementing SDIO WiFi Module sometime in the future. WRT your question, I'm no software guy (not since the days of ZX81 BASIC)... I understand the I2C port connected to the GPIO expander that drives the various internal I/O's (incl...
by John Westlake
Sat Jul 07, 2018 6:01 pm
Forum: Compute Module
Topic: Missing Capacitor C56
Replies: 2
Views: 703

Re: Missing Capacitor C56

I believe U5 and U6 are 1.2V LDO regulators:-

RT9081A-12GQZA

https://www.richtek.com/assets/product_ ... 81A-00.pdf

C56 is a 1uF (I'd guess 4V (Could be 6.3V) X5R 1005).

1005 = 0402 :)

C56 is used to decouple the 1.8V input to the LDO.
by John Westlake
Sat Jun 30, 2018 6:52 pm
Forum: Compute Module
Topic: Integrating BCM43438-based SDIO WiFi Module on CM3
Replies: 6
Views: 6063

Re: Integrating BCM43438-based SDIO WiFi Module on CM3

Have you connected LPO_IN pad F5 (Low Power Oscillator IN) the 32.768KHz secondary clock to a GPIO on the CM3? These are the GPIO used on the RPi3:- pin@p14 { function = "uart0"; termination = "no_pulling"; drive_strength_mA = < 8 >; }; // TX uart0 pin@p15 { function = "uart0"; termination = "pull_u...
by John Westlake
Tue Jun 26, 2018 6:01 pm
Forum: Compute Module
Topic: Lan9512 stops working
Replies: 9
Views: 1207

Re: Lan9512 stops working

Yes, pretty sure the issue was the missing 1M Resistor across the Crystal - this bias the LAN9514 Oscillator circuit into its linear region. I'd also connect VBUSDET to VDD33IO. If it helps your PCB layout (extra Ground paths) then TMS, TDI & TCK can be Grounded (Leave TDO open). NTRST can be connec...
by John Westlake
Tue Jun 26, 2018 5:26 pm
Forum: Compute Module
Topic: Lan9512 stops working
Replies: 9
Views: 1207

Re: Lan9512 stops working

Yes, try a 1M resistor across the Crystal :)
by John Westlake
Tue Jun 26, 2018 5:24 pm
Forum: Compute Module
Topic: Any interest in a custom heat sink for CM3?
Replies: 1
Views: 683

Re: Any interest in a custom heat sink for CM3?

We ended up using a fairly large heatsink (Small 14mm X 14mm heatsinks are pointless) which is attached by self adhesive tape, but I worry about the heatsink dropping off during shipping. https://www.dropbox.com/s/x65v2nd71kpoes1/CM3%20Heatsink.jpg?dl=0 We also used a thermal pad that transfers heat...
by John Westlake
Sun Jun 24, 2018 5:47 am
Forum: Compute Module
Topic: LAN9514 chip troubleshooting
Replies: 9
Views: 2158

Re: LAN9514 chip troubleshooting

Great its now working :) More then happy to give a quick check of your schematics next time round... I'm retired here in the Czech Rep. and bored - so happy to keep dabbling... :) I've been battling thermal issues with the CM3, so if you plan to use the CM3 heavily loaded you really need to take car...
by John Westlake
Fri Jun 22, 2018 2:53 am
Forum: Compute Module
Topic: LAN9514 chip troubleshooting
Replies: 9
Views: 2158

Re: LAN9514 chip troubleshooting

Maybe the trouble is with the Reset as mentioned already - I've found that for "First Boot" Reset is not required (if you reboot the Pi you should also reset the LAN9514). So try disconnecting the LAN Reset line to the CM3 and see if there is any change (leave it pulled-up via the 10K you mentioned)...
by John Westlake
Tue Jun 19, 2018 9:19 pm
Forum: Compute Module
Topic: LAN9514 chip troubleshooting
Replies: 9
Views: 2158

Re: LAN9514 chip troubleshooting

Can you post the schematic of the Section? Some thoughts:- 1. If the EEprom is fitted (but blank) have you tried to remove it? 2. Is the 25MHz clock good? As Linux is rather cyptic - in the past when I was fighting such issues I connected the LAN9514 USB Host upstream connections (that would normall...
by John Westlake
Mon Jun 18, 2018 2:30 am
Forum: Compute Module
Topic: Cost of design a CM IO board?
Replies: 3
Views: 798

Re: Cost of design a CM IO board?

You could get a decent university student to design a simple PCB for GBP1K to GBP2K, if you require a correctly impedance matched USB / HDMI then it requires more design skill... Working with the CM3 is easy "schematically" however most components are fine pitch / leadless / BGA so this increases th...
by John Westlake
Sat Jun 09, 2018 12:12 pm
Forum: Compute Module
Topic: Recommend contract designer for CM3 IO board?
Replies: 5
Views: 2093

Re: Recommend contract designer for CM3 IO board?

It depends whats required, but we have a handful of Projects based on the CM3 so have now built up a far bit of experience with CM3 based designs. I also have small scale inhouse manufacturing and testing based in mainland Europe (not the cheapest but OK for small volume / prototypes).... PIng me a ...
by John Westlake
Mon May 28, 2018 5:17 pm
Forum: Compute Module
Topic: Dynamic profile VCore difference between RPi3 & CM3
Replies: 28
Views: 3436

Re: Dynamic profile VCore difference between RPi3 & CM3

Could we please have some official comment from RPi about what performance impact with CM3 verse RPI3 we should expect? At the moment we see the CM3 almost permanently throttled while no thermal issues are encountered with the RPi3 with the same software. Does RPi have some test suit we can use to e...
by John Westlake
Mon May 28, 2018 12:29 pm
Forum: Compute Module
Topic: Dynamic profile VCore difference between RPi3 & CM3
Replies: 28
Views: 3436

Re: Dynamic profile VCore difference between RPi3 & CM3

Although I can't offer any particular help for solving your problem I would like to know if this could be solved by having a compute module based on BCM2837B0. Does anyone know if the BGA footprint is the same for the BCM2837 & BCM2837B0 - if they are the same then I can transplant a BCM2837B0 onto...
by John Westlake
Mon May 28, 2018 10:05 am
Forum: Compute Module
Topic: Dynamic profile VCore difference between RPi3 & CM3
Replies: 28
Views: 3436

Re: Dynamic profile VCore difference between RPi3 & CM3

Phil, I'm away from the Lab until later this afternoon, as soon as I return I'll run the tests. Maybe the title of this thread is causing some confusion - but the reason behind the thread is to understand why we have serious overheat issues with CM3 where we have non with RPi3. In the overheat threa...
by John Westlake
Sun May 27, 2018 8:08 pm
Forum: Compute Module
Topic: Dynamic profile VCore difference between RPi3 & CM3
Replies: 28
Views: 3436

Re: Dynamic profile VCore difference between RPi3 & CM3

A gentle Ping to my earlier post above please :) ...

I've noticed that there are more reports of CM3 Overheat issues:-

viewtopic.php?f=98&t=175523
by John Westlake
Sun May 27, 2018 8:00 pm
Forum: Compute Module
Topic: CM3 always crashes within minutes under load
Replies: 39
Views: 6188

Re: CM3 always crashes within minutes under load

Also it has been suggested that the thermal performance difference between RPi3 and CM3 is due to the smaller PCB heatsinking area of the CM3 module - but this FAILS to explain why we still have thermal issues when a heatsink is added to the CM3 - I cannot believe that a BGA device mounted on standa...

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