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by mkirk
Tue May 14, 2019 10:15 pm
Forum: Troubleshooting
Topic: Packet loss/dropout with iperf3 - UDP
Replies: 4
Views: 130

Re: Packet loss/dropout with iperf3 - UDP

Continue to see data rate drops. iperf3 test runs at 28 to 40 Mbps for hours then drops to 2-4 Mbps for 4 hours then recovers and goes back to 28-40 Mbps. What could cause this ? Test was running for 24 hours.
by mkirk
Wed May 08, 2019 6:39 pm
Forum: Beginners
Topic: Sustained WiFi speed on Pi 3B?
Replies: 1
Views: 59

Re: Sustained WiFi speed on Pi 3B?

Also should note that WiFi CYW43438 chip is only capable of +19 dBm (80 mW ) of Tx power, but iwconfig shows it is +31dBm (> 1 watt). So iwconfig not an accurate indication of Tx power. wlan0 IEEE 802.11 ESSID:"pi45ap" Mode:AdHoc Frequency:2.437 GHz Access Point: B8:27:EB:0C:56:F6 Tx-Power=31 dBm Re...
by mkirk
Wed May 08, 2019 6:29 pm
Forum: Beginners
Topic: Sustained WiFi speed on Pi 3B?
Replies: 1
Views: 59

Sustained WiFi speed on Pi 3B?

We are trying to benchmark Pi 3B WiFi speeds with iperf, iperf3 and nuttcp. Transferring TCP mode with unlimited rate. Running Raspbian Stretch release. 2.4 GHz, channel 6 on-board WiFi in ad-hoc mode (no Access point or router) - on-board chip antenna One Pi 3B is server the other is a client. Test...
by mkirk
Fri Apr 05, 2019 6:51 pm
Forum: Troubleshooting
Topic: Packet loss/dropout with iperf3 - UDP
Replies: 4
Views: 130

Re: Packet loss/dropout with iperf3 - UDP

Is there a log file for the CYW43438 WiFi/BLE chip that shows fault events or other indications when it stops transmitting?
by mkirk
Fri Apr 05, 2019 4:49 pm
Forum: Troubleshooting
Topic: Packet loss/dropout with iperf3 - UDP
Replies: 4
Views: 130

Re: Packet loss/dropout with iperf3 - UDP

New issue with this evaluation. I am getting a periodic (1 minute) dropout of WiFi signal (no RF on spectrum analyzer) using the nuttcp tool. I can't understand what would shutdown WiFi, the onboard Bluetooth is disabled. Log file is below. One Pi is set up as Access Point (hostapd/dnsmasq) and othe...
by mkirk
Fri Mar 22, 2019 8:17 pm
Forum: Troubleshooting
Topic: Packet loss/dropout with iperf3 - UDP
Replies: 4
Views: 130

Re: Packet loss/dropout with iperf3 - UDP

Some progress on this issue. For TCP tests, iperf3 bandwidth is unlimited which means it will try and push as much data as possible through the link. This would cause the task to run out of buffers and require a buffer recovery. During this interval, no data is sent. It would not be caused by the bu...
by mkirk
Fri Mar 22, 2019 7:01 pm
Forum: Troubleshooting
Topic: Packet loss/dropout with iperf3 - UDP
Replies: 4
Views: 130

Packet loss/dropout with iperf3 - UDP

iperf3 tests are run with UDP between 2 Pi 3B boards over the on-board WiFi ( channel 6 = 2.437 GHz) Server Pi is set up as Access Point (hostapd/dnsmasq) and client Pi is attached. Below is an example where iperf3 has zero data transfer for a full 1 second period (32-33 seconds). Just prior there ...
by mkirk
Thu Mar 21, 2019 2:12 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Re: Pi 3B male 40 pin header - gold, nickel or tin plating?

Jamesh, Thanks, I was not aware of the newly released CM3+ with the extra eMMC options. I will bring this option up with our design team. We started our design evaluation back in November 2017, the CM3+ was not available then. The 4GB eMMC on the CM3 was not sufficient - we needed 16GB ( now availab...
by mkirk
Wed Mar 20, 2019 10:51 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Re: Pi 3B male 40 pin header - gold, nickel or tin plating?

Primarily cost. Pi 3B is $35 and it includes WiFi/Bluetooth, Ethernet/USB, onboard antenna. CM3 is $35 from Newark (USA) without WiFi/BT, Ethernet/USB chips Plus the carrier board has the added cost of connectors: SIMM (CM3), Camera ribbon, Ethernet and USB. All of these would add $15 to cost of CM3...
by mkirk
Wed Mar 20, 2019 9:08 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Re: Pi 3B male 40 pin header - gold, nickel or tin plating?

Jamesh, I am not questioning the post about the 3 types of plating. That is what I accept. However, it will force us to buy 2 connector types (Gold and Tin plating ) to match the batch of Pi modules at the time of manufacture. This increases our parts cost. (Phosphor bronze is copper-tin alloy and i...
by mkirk
Thu Mar 14, 2019 4:39 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Re: Pi 3B male 40 pin header - gold, nickel or tin plating?

Pi Foundation has update: header contact plating could be tin, gold or phosphor-bronze (copper-tin-phosphorus alloy) Mike It will depend on what version etc. It can be either tin plated, gold or phosphor bronze. We can't say which version will be on which Pi. Regards Nicola Early Administrator =====...
by mkirk
Wed Mar 06, 2019 3:41 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Re: Pi 3B male 40 pin header - gold, nickel or tin plating?

I sent a query to the Pi Foundation support team to confirm - here is the response:

Thank you for your interest in Raspberry Pi.
It (header connector) is tin plated.
https://www.raspberrypi.org/products/ra ... 3-model-b/

Regards,
Nicola Early
Administrator
by mkirk
Tue Mar 05, 2019 4:15 pm
Forum: General discussion
Topic: Why PIN headers instead of female PIN headers?
Replies: 11
Views: 566

Re: Why PIN headers instead of female PIN headers?

Does anyone know what plating is used on the 40 pin header?
Phosphor-bronze (copper-tin), tin, gold, nickel or other?

Regards, Mike
by mkirk
Mon Feb 25, 2019 9:51 pm
Forum: General discussion
Topic: Pi 3B male 40 pin header - gold, nickel or tin plating?
Replies: 15
Views: 821

Pi 3B male 40 pin header - gold, nickel or tin plating?

Is there a part number or specification for the male 40 pin (2x20) header on the Pi 3B? Is the mating surface gold plated? It is gold in color, but could be nickel plating or other material. For long term reliability, we want to select a mating female connector for our HAT board that has compatible ...
by mkirk
Tue Feb 12, 2019 10:21 pm
Forum: Compute Module
Topic: How to enable boot messages over UART
Replies: 2
Views: 3238

Re: How to enable boot messages over UART

in the cmdline.txt file, remove the word "quiet" to allow display of boot activity.
by mkirk
Fri Jun 01, 2018 8:06 pm
Forum: General discussion
Topic: Raspberry Pi - export restrictions due to crypto?
Replies: 8
Views: 903

Re: Raspberry Pi - export restrictions due to crypto?

Thanks. These links seem to answer my first question, but not the second regarding crypto restrictions
by mkirk
Fri Jun 01, 2018 5:04 pm
Forum: General discussion
Topic: Raspberry Pi - export restrictions due to crypto?
Replies: 8
Views: 903

Raspberry Pi - export restrictions due to crypto?

I searched the forums but could not find my answer. Please point me to any relevant links. If Raspberry Pi is included in a product, can the Pi be shipped worldwide from USA without restrictions? Does Raspberry Pi contain any encryption/crypto hardware (CPU/GPU/coprocessor), bootloader or functions ...
by mkirk
Mon May 14, 2018 2:25 pm
Forum: General discussion
Topic: FCC Part 15 C Testing
Replies: 8
Views: 1310

Re: FCC Part 15 C Testing

Are these tools and procedures available somewhere on the PI website or Github? Or do I need to make the request to [email protected] as well.?
by mkirk
Fri Apr 27, 2018 4:34 pm
Forum: Compute Module
Topic: WiFi chip for Compute Module 3
Replies: 18
Views: 17005

Re: WiFi chip for Compute Module 3

Thanks to all for the great information!
by mkirk
Mon Apr 23, 2018 9:16 pm
Forum: Compute Module
Topic: WiFi chip for Compute Module 3
Replies: 18
Views: 17005

Re: WiFi chip for Compute Module 3

Does anyone know the interfaces (port pins) on the Pi 3B BCM2837 SoC for the Wifi/BT chip CYW43438 (was BCM43438)? The part is CYW43438 (now Cypress) datasheet http://www.cypress.com/file/298076/download and part is available from US distributors Arrow, DigiKey and Mouser. So can this be wired to th...
by mkirk
Mon Apr 23, 2018 8:49 pm
Forum: Advanced users
Topic: Which Wifi/Bluetooth chip does the RPi 3 model B integrates?
Replies: 13
Views: 11590

Re: Which Wifi/Bluetooth chip does the RPi 3 model B integrates?

Cypress bought Broadcom's wireless business in 2016.

Here is datasheet on the WiFi/BT BCM43438 (now CYW43438) part: http://www.cypress.com/file/298076/download

Does anyone know how chip is wired into the SoC - what pins are used?
And are these pins available on the Compute Module 3 connector?
by mkirk
Tue Mar 06, 2018 4:28 pm
Forum: Troubleshooting
Topic: Wifi connection unstable
Replies: 54
Views: 26382

Re: Wifi connection unstable

For this dropped WiFi issue with Cypress chipset, could Moderator jamesh be specific as to what releases (with dates) of Jessie or Stretch has the Cypress driver bug and which has the backed out fix? I am running : Linux raspberrypi_10 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Lin...

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