Hello Community Members,

This BLOG should be used as a "guide" for creating the PCB Layout for the BCM20732S Module.

The first attachments are:

1. BCM20732S_GERBER.zip - The gerbers of a sample layout.
2. BCM20732S_Allegro_CircuitBoard_Files.brd - Allegro circuit board file
3. BCM20732S_AltiumFootprint.PcbLib - Altium Foot Print
4. Sample_BCM20732S_Schematic.pdf - Schematic file.
5. BCM20732_SB-BLE-S03_PEVB_BRCM_V10_20130813_Allegro.dsn - Allegro Design File

Notes:

• You can view this PCB file by downloading a FREE Allegro PCB viewer from the following link:
• http://www.cadence.com/products/pcb/Pages/downloads.aspx
  
  You will probably have to register on Allegro website before you can download the viewer.
• Ensure you download this version:  "Reads designs for versions 15.x to 16.6. Requires a Windows OS"

I will include a description after this post to discuss the details and answer any questions.

Thanks

JT

How to debug non-responsive customer based hardware

So, you've got your custom hardware back from the build facility.  It's populated with one of those sexy Broadcom Bluetooth devices.  An exuberant crowd of managers and team leaders is milling about the lab, watching with anticipation as you attach the power source.  The gleeful moment arrives, and you flip the switch to ON -- Viola!  ...  Nothing happens.  Nada.  Zip. Nilch.   Maybe you had expected the board's LED to start pulsing indicating the application firmware (pre-programmed into the non-volatile memory) is running.   You did pre-program the EEPROM/SFLASH right?   Maybe you're just happy there was no smoke, popping sounds, or the acrid smell of "burnt Roast Beef" when the design is bad, or assembled using wrong/misplaced component(s).  With a "pat on the back" and some encouraging words, management slinks-away to perform whatever their job function is; leaving you scratching your head and saying "Huh?".  You reach for the schematics and an oscilloscope probe...    Now what do you do?

Before you post a help request on the Community Forum (Bluetooth Forums​), please consider some of the fundamental steps Broadcom recommends you try first.

We remind the reader there are three topologies in which Broadcom devices can operate which may impact how to debug the design:

1. Chip on Board or System On a Chip (COB and SOC terms can be used interchangeably) - SOC designs use discreet components and are often very similar to Broadcom's TAG3 or TAG4 evaluation boards.  In SOC designs, the (integrated) Broadcom radio and MCU is populated as one-component with additional circuitry added around it, such as the EEPROM, ferrite beads, capacitors/resistors, antenna, and (optional) 32KHz crystal.  Broadcom's Bluetooth SOC device stenciling (part number markings) DO NOT end with the letter S, L, or an E  and come in a 32pin QFN package.  SOC designs are perhaps easiest to debug because you can get a scope probe on virtually everything that can go wrong.  Note: Devices stenciled with an S, L, or an E are covered next under the SIP topology.
2. System In Package (aka SIP) - a SIP offers the majority of the necessary components all-in-one package, including the antenna.  They come with (Limited Module) FCC/UL/CE pre-certifications resulting in your company only needing to perform Spurious Emissions testing.  Certifications can save hundreds of thousands of dollars, not to mention time to market and testing hassles. Some customer designs consist of only the Broadcom SIP and a battery!   Presently, three flavors of the SIP are available and offer different features depending on the requirements (power, size, RF expertise, etc). These part numbers end with an S, L, or an E and come in a 49pin LGA package.   SIPs are rarely defective, so debugging them is usually a function of getting the on-board 64k-byte EEPROM programmed with the users application.
3. Modules - Broadcom's Partners offer world-class products and services!  Our partners offer everything from device procurement, design services, Broadcom SDK Abstraction, FCC/UL/CE certified modules, to mass production and plastics up to and including Cloud Services. If you're reading this debug Blog, chances are you are not using one of our partner's devices/services because it would already be working for you.

Debugging hardware is easier when able to perform A<->B comparison tests/measurements against a known-good design.    You can purchase a  Broadcom TAG3/TAG4/WICED-Sense evaluation board, or evaluation boards from Broadcom's partners (Partners) at this link:  Purchase a WICED Bluetooth Development Kit

Documentation for the TAG3/TAG4 (COB/SOC) eval boards, and SOC/SIP Technical Reference Manuals are found here: WICED Bluetooth Documents & Downloads​. 

While debugging, you must have access to these pins (at a minimum):   VCC/VDD/VIN, HCI_UART_TX, GND, HCI_UART_RX, RESET_N

During debug/initial programming of the NVRAM, it's strongly advised to use a USB<->RS232 serial cable (one option is model #TTL-232RG-VREG3V3-WE found here: Programming the TAG2/TAG3 Board using command line tools).

Debug steps:

1. Visual Inspection for Mechanical / Assembly problems - Grab your magnifying glass and meticulously inspect both sides of the printed circuit board (PCB). Does anything look bent, damaged, or out of place?  Are there any solder bridges, or open-connections on the fine-pitch (device) pins?   Does anything look like it has experienced high-heating duress?  Are their any cracks in the PCB?
2. 'Buzz Out' (use a Volt-Ohm meter to make resistance and continuity measurements of) the Power and Ground Rails going to each device and component that touches them.   Measure resistor values for for each resistor shown on the schematics.  Verify any diodes or resistors in the design are installed in the correct direction.
3. Verify VCC/VDD is 3.3volts.
4. Measure the amount of power the board is consuming.  Does it seem excessive, or too small?   Are any of the components hot-to-the-touch?
5. Confirm the timing of the RESET signal going to the BCM2073XX meets the timing requirements. Confirm the device is not being held in RESET which would happens when RESET_N pin is held low.
6. There are two UARTs on the device.  HCI_UART is used for programming NVRAM, and PUART is available for the users application. Upon powerup, the BCM2073XX device ROMCODE senses the HCI_UART_RXD pin to ascertain if it should enter programming mode.  If asserted HIGH, the device enters programming mode. If low, it reads a small chunk of NVRAM contents. One good way to test if the on-board ARM is running romcode is to hold HCI_UART_RXD high during the RESET pulse to force it into programming mode.  Then, execute the ~WICED-Smart-SDK/Tools/mbt/MBT.EXE utility(within the SDK) with the "reset COMxx" parameters to verify HCI Commands/Responses are working.    It is very important to get this to succeed as it confirms there are no electrical or mechanical issues causing the problem(s), and that the embedded ARM controller is indeed running firmware.
7. If MBT.EXE does not successfully run, Inspect the following areas:
   • Either chip on board design, or module/SIP designs:
     1. If your design has a 2nd microcontroller in place, verify the UART interface signals are not reversed.  In fact, you might want to isolate the Broadcom chip (cut the traces to the host MCU) to assist getting MBT.EXE to function, or to aid in programming the NVRAM with the SDK.
   • Chip on Board designs (BCM2073X):
     1. Ensure the voltage levels for LDOIN/LDOOUT/VDDVCO/VDDPLL match those found on the Broadcom Evaluation Board.
     2. Ensure the 24MHz crystal running.
     3. Ensure TMC is asserted low.
     4. Monitor the Serial Flash/EEPROM's SDA and SCL pins after the RESET is de-asserted on the BCM2073X. You should see bus activity for a short period of time as the internal ARM MCU comes out of reset (ROMCODE tries to load the application firmware from NVRAM).  Make sure you have pullup resistors on these pins.
     5. If the NVRAM has a known-good application image in it, ensure the HCI_UART_RXD pin of the 2073XX is asserted Low during powerup.
   • Module/SiP designs (BCM2073XS, BCM2073XL, BCM2073XE):
1. These designs are difficult to debug because access to the crystal and NVRAM pins are not accessable from outside the package.
2. Spend your entire effort getting Step #6 (execution of MBT.exe) functioning to ensure the issue is not a mechanical/electrical one.
3. Consider NVRAM pre-programming services from Avnet to ensure the module has a known-good application programmed prior to board manufacturing.
8. After getting MBT.EXE working, your next step is to program the NVRAM with your custom application, or a sample application from the SDK.  Refer to Programming the TAG2/TAG3 Board using command line tools\

If you find an error within this Blog, or have ideas on how to improve it, please send a Private Message to my In-Box so I can incorporate your recommendations.

Please do not post comments on this blog.

The WiFi module power and reset pins are controlled by the host MCU.

BCM943362WCD4:

For BCM943362WCD4 evaluation board, the power and reset pins are controlled by the following definitions in .../platforms/BCM943362WCD4/platform.c

[WWD_PIN_POWER] = { GPIOB,  2 },
[WWD_PIN_RESET] = { GPIOB,  5 },

The "WWD_PIN_POWER" definition in WICED SDK controls the host MCU (STM32F205) PB2 pin. The host MCU PB2 pin controls the VBAT (power) on the WiFi module. Wifi module power completely turned of by the hos MCU to save energy if the WiFi module is not in use at all.

The "WWD_PIN_RESET" definition in Wiced SDK controls the host MCU PB5 pin. The host MCU PB5 pin controls the WLAN_RESET_L (reset) on the WiFi module.
Setting this pin logic level to low causes WiFi module reset.

BCM943341WCD1:

For BCM943341WCD1 the reset pin is controlled by the following definition in .../platforms/BCM943341WCD1/platform.c

Although it is named as WWD_PIN_POWER but actually controls the reset pin of the BCM943341 SiP module. Reason is being the logic level to reset the BCM943341 SiP module is inverted compared to the other SiP modules.

[WWD_PIN_POWER] = { GPIOB,  2 },

The "WWD_PIN_POWER" definition in WICED SDK controls the host MCU (STM32F417IGH6) PB2 pin. This pin from the host MCU controls the WL_REG_ON (reset) on the WiFi module.  Setting this pin logic level to high causes WiFi module reset.

Unlike on BCM943362WCD4 evaluation board, on BCM943341WCD1 evaluation board the WiFi module power (VBAT) is not controlled by the host MCU. The WiFi module VBAT pin directly connected to the 3.3V via bypass capacitors.

If needed, the similar power switching circuit from BCM943362WCD4 evaluation board could be used on BCM943341 module based designs as well.

.

                                   

• Code Overview
  
  • iBeacon and SDK 2.1 Code Overview
  • WICED Smart BCM2073X Coding Tips from user maxsong...
  • WICED Smart Training videos, compliments of Macnica North America...
  • BCM92073X BLE Profile Configuration

• General Questions
  
  • BCM20732 questions
  • How to get started (coming from arduino)
  • What is difference between being connected versus paired?
  • Wiced Smart Software Runtime -- Lots of Questions
  • About BCM20737S
  • BCM20737s: NFC Reader or only TAG?

• Hardware Design between 2073X and External MCU

• Reference Design/Schematics
  
  • New iBeacon BCM20737 Reference Design
  • Experts Interview Video: Michael L. - IBCN BCM20737 Schematic Review
  • BCM20737TAG Board - Gerbers and Schematics

• Layout
  
  • BCM20732 layout options
  • BCM20737S input capacitors and placement
  • BCM20732S layout
  • Are pullup resistors always needed on 20732 SCL and SCA pins?
  • Exact Location of internal PIFA Antenna on BCM20737S
  • 20732S XTAL (32KHz)

• General
  
  • WICED Smart Video BLOG: SDK 2.1 Smart Designer Tool Walk-Thru
  • WICED Smart BCM92073X GATT DB Operation
  • Lots of questions.. L2CAP/GATT/GAP, etc
  • Multiple Notifications in an App...?
  • Support for very large characteristics

• Other
  • How to change the GATT database after init (bleapp_set_cfg) ?
  • Is pairing/encryption mandatory to allow a peer to write in GATT

• Advertising
  
  • Customizing Advertising on WICED Smart
  • Best way to rewrite advertisement data
  • Connectable vs. nonconnectable Advertisements.
  • How to change advertisement interval after init?
  • Advertising during connection
  • bleprofile_notifyAdvPacketTransmissions doesn't work.

• Callback to modify single advertisments?
• About the bleprofile_GenerateScanRspData function?
• How to register callback for ADV events ?

• Scanning
  
  • Scan sometimes stops working
  • Scheduling of scan window and connection window

• Additional master/slave questions on BCM20736/7 family
• Re: How best to implement bulk data transport
• smp_bond_result 04
• Connection Event Callback API
• Connection Event Callback API (follow-on)
• Connection Interval and Connection Slave Latency
• When does bleprofile_sendNotification() actually send?
• Check if bleprofile_sendNotification() was successful
• Slow reconnection
• Sometimes connection not bonding

• Adding and removing master nodes to a whitelist running on a peripheral device

• General
  
  • BCM2073XS GPIO Basics
  • Can someone tutor me on GPIO usage?
  • GPIO Headers
  • BCM20732S PIN information
  • BCM2073xS (BCM20737S) GPIO bonding

• Interrupts
  • Access_tag_interrupt_handler
  • How to identify GPIO interrupt source pin?
  • Buttons in hello_sensor.c
  • How can I wake BCM20737S up by using GPIO interrupt?
  • How to disable interrupt?
  • GPIO in high impedance mode
  • Wake up on GPIO interrupt

• General
  
  • Information: Debug the BCM20732 Tag over HCI-UART using a COM port via USB on the PC
  • How to debug the board step by step?
  • Information: BCM20732S debug/trace capabilities through the HCI UART port
  • How do I interpret the extra tracing data ?
  • Testing Master and Slave Roles
  • How can I use ble_trace() for application debug?
  • How to get debug traces ?
  • WICED Sense debug with UART
  • How to disable 20737S SDK trace, BLE_TRACE_DISABLE?

• J-Link
  • WICED Smart J-Link Debugger
  • WICED Smart - Debugging Support Using a J-Link Probe Application Note

• BCM92073X TAG Power Supply Configurations
• Power level granularity in blecm_setTxPowerInConnection() and blecm_setTxPowerInADV()
• Current Draw and Advertising Timing on the WICED Sense (BCM20737S)
• how to reduce the power consumption when use puart ?
• BCM20737S Current Consumption Voltage Condition and more...
• [BC20636S] Power consumption advantages when using external oscillator

• BLE RF Testing Specification Introduction
• BLE RF Testing Setup Procedures

• General
  
  • WICED Smart Video BLOG: Experts Interview - Sleep Deep_Sleep and Advertising
  • Sleep Deep_Sleep Explanation and Techniques
  • WICED Smart Sleep/Deep-Sleep Explanation and Techniques Design Guide
  • BCM20736S Sleep Example Firmware
  • Questions sleep and deep sleep modes on BCM20737
  • GPIO Interrupt State after Deep Sleep

• Entering Sleep
  
  • How to enter HIDOFF?  How to detect if the request is not honored?
  • Putting '20732S into sleep or deep sleep mode
  • BCM20736S HIDOFF problem
  • Problem with sleep mode
  • Sleep Mode on 20736S

• Waking From Sleep
  • Boot Time of WICED Smart Tag Board (BCM20737)
  • GPIO state in deep sleep
  • For wake on GPIO interrupts, please look under GPIO->Interrupt
    

• WICED™ Smart Hardware Interfaces
• BCM20736S I2C, PUART and SPI comms
• SPI1 access or send command to flash in application level.

• Memory:
  • BCM20732 Memory Map Architecture
  • BCM92073X TAG Memory and Programming Configurations
  • WICED Smart BCM92073X I2C EEPROM Emulation Porting Guide
  • WICED Smart BCM92073X EEPROM and SFLASH Layout
  • WICED Smart BCM92073X NVRAM Access
  • Memory size limits on 20732?
  • BCM20732S NVRAM Size
  • nvram: number of locations to write to
  • BCM20736S I2C, PUART and SPI comms
  • It seems that I can not read the data is stored in NVRAM before the last power off.
  • Layout of VS1 in the EEPROM
  • Re: Accessing the 512 kb (64 kB) EEPROM in the 20737S module

• PWM:
  • LED with PWM
  • Different Frequencies for PWM
  • How many PWM channels available in BCM20732S ?
  • BCM92073x periodic interrupt rate
  • How to turn on LED

• ADC:
  • BCM20732S ADC Configuration
  • Questions related to the ADC implementation on the BCM2073XS...
  • ADC on BCM20732

• UART:
  • Information: Programming your BCM20732S-based board from an onboard UART header
  • UART does not receive
  • UART Routines
  • BCM20732S based boards sometimes develop UART failure
  • Spec for uploading firmware to the BCM20732S via HCI UART?
  • puart_write() crashing on BCM20736?
  • Peripheral UART missing bytes
  • Problem with UART watermarks
  • PUART RTS/CTS Hardware Flow Control
  • What are the PUART FIFO Rx interrupt threshold settings?
  • Need clarification on PUART RTS/CTS flow control support

• I2C:
  • I2C Discussion
  • BCM20736S recovery problem - SDA high does not enter recovery mode
  • How can I use i2c in BCM20737S?

• SPI:
  • SPI on BCM920732TAG
  • Spi Debug
  • SPI flow control

• Timer in 2073x
• BCM20737S Timer Module

• Software/Usage
  
  • appFineTimer
  • FineTimer
  • What is the best way to set an application timer to fire?
  • how to config RTC use external 32.768?
  • Re: How to use real time tick clock?
  • rtc_sample bricks our BCM20736S-based board
  • Turning off the timers in BCM20736S
  • Hello_client/blecen Timer Callback Questions

• Watchdog Timer
  • How can I get bcm20732s reset reason?
  • Increasing/Disabling the watchdog timer

• Crystal
  • Explanation of Crystal Warmup Issue
  • Crystal warm-up work-around video...
  • 32kHz Crystal Spec?
  • Internal vs. External Oscillator

• RTC
  • rtc_RtcTime2Sec() returns wrong seconds when RtcTime.year is 2016
  • How to use real time tick clock?
  • rtc_sample bricks our BCM20736S-based board
  • how to config RTC use external 32.768?

• Watchdog Timer
  • Increasing/Disabling the watchdog timer
  • How can I get bcm20732s reset reason?

• Hardware Timer
  • How to use 100us interval timer?
  • Hardware Timer (hw_timer.h) usage
  • HW Timer in 2073x
  • Timer in 2073x
  • Wiced Sense hardware timer example
  • Wiced Sense hardware timer example (part 2)

• WICED Smart BCM92073X OTA Firmware Upgrade (1)
• WICED Smart BCM92073X OTA Firmware Upgrade (2)
• How to do OTA: Step by Step with PDF
• SOTAFU for Android and iOS
• Why error occur when I open WsOtaUpgrade.exe?
• Why error occur when I open WsOtaUpgrade.exe? (continued)
• Issue with using Windows OTA upgrade app

• How to recover BCM20736S on custom board?

Security:

• Encryption API
• How to operate RSA in BCM20737S & BCM20737S document
• Update on RSA and/or app note for BCM20737?
• BCM20736S and RSA
• RSA Document
• BCM20737S: LE security mode1 level3/4 supported?

• Programming manufacturing data during production
• Do I need to register separately with the Bluetooth SIG to use the Bluetooth logo in my product?

• BD_ADDR - how do you get one?
• BD_ADDR: Changing BCM20737 Board Address for Production
• Changing BD_ADDR from the application
• Video Link : 1216

• Programming the TAG2/TAG3 Board using command line tools
• BCM20732S refuses to program
• cgs.exe and ChipLoad.exe

• WICED Smart BCM92073X Generate Your Own UUID

• Broadcom BCM20732S/BCM20736S/BCM20737S Regulatory Approvals
• Certification from Bluetooth SIG
• 20732S regulatory certification
• More questions regarding FCC certification on the BCM2073XS Product
• FCC Certification Flow for Broadcom module products
• FCC approval for BCM20736S

Hello Community Members,

This BLOG should be used as a "guide" for creating the PCB Layout for the BCM20737 device using the BCM20737TAG Board as a reference.

The first attachments are:

1. BCM20737TAG_GERBERS_RevA.zip - The gerbers of a sample layout.
2. BCM20737TAG_Allegro_CircuitBoard_Files.brd - Allegro circuit board file

The Schematic source will be added later

Notes:

• You can view this PCB file by downloading a FREE Allegro PCB viewer from the following link:
• http://www.cadence.com/products/pcb/Pages/downloads.aspx
  
  You will probably have to register on Allegro website before you can download the viewer.
• Ensure you download this version:  "Reads designs for versions 15.x to 16.6. Requires a Windows OS"

I will include a description after this post to discuss the details and answer any questions.

Please refer to the latest documents related to the BCM20737TAG Board:

BCM20736 Product Brief

WICED Smart Quick Start Guide (SDK 2.x and TAG3 Board)

Note: mwf_mmfae moved all design files previously attached to this blog to the dedicated TAG3 Category here within the Documents and Downloads section: WICED Smart Documents & Downloads

Thanks

JT

Michael L. takes us through a Schematic Review of the iBCN BCM20737 Reference Design.

Thank you Michael.

WICED Smart Documents & Downloads

The schematic is located:

iBeacon BCM20737 Reference Design Schematic (PDF)

The Gerbers are listed here:

iBeacon BCM20737 Reference Design Gerber Files

He discusses:

1. The Baseband section of the BCM20737
2. Recovery Process
3. Common mistakes he has seen from designers
4. Decoupling Caps for the Pins and RF section

Video Link : 1142

Let us know if you have any questions

Thank you

JT