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Smart Bluetooth

ThYo_2228536
New Contributor II

Recommendation for "future" board to replace  BCM92073X_LE_KIT

1) Pin Header : not convenient at all to wire TP6 for SPI CLOCK and TP7  for MISO in the back of the board to be able to configure SPI in MASTER2_P24_CLK_P04_MOSI_P25_MISO

2) Default voltage of the board is 1.2 V or so. While it is good as a marketing point of view to sell low power BLE using coin cell, it uis not good enough to power SPI slaves.

3) SPI driver in wiced smart is not as good as STM SPI driver today.  WICED WIFI uses STM for SPI and Host MCU.

Using Host MCU for BLE is a good idea but it is not full feature enough to be abke connect with ALL third party devices out there.

I found issues with Analog Device ADC as well as  Linear LTC2983 SPI ADC. All those board are requiring 3.3 V mimimum.

It looked like when trying to power SPI slave through BLE as 3.3 V after HW modification. SPI MISO, CLOCK and MOSI are all screwed up although the 3.3 V modidief board was able to drive the  Aardvark SPI/I2C Atmel Connectivity demo board,

So it looked like a build in level shifter would be needed or some sort.

I am not an hardware engineer but just felt the frustration not beeing able to read anything using SPI master interface after the board was modified for 3.3 V.

Finally I noticed that idevice Connected Devices - Bluetooth Module & Product Development | iDevices LLC is using "iDevices Bluetooth Smart Module from Broadcom" as a platform that can simply connect to their favorite CPU/Micro-controller via a UART interface.

It is interesting that they decided to use UART for iGrill  to have BLE communicate with a bigger Host MCU over UART to exchange data back and forth and let the HOST MCU deal with SPI communciation with Thermocouple and ADC. It looked like it confirms that SPI driver is better on STM today. It is too bad because on paper the BLE should be able to drive 4 SPI slave device.

If Broadcom want to connect everything then the eval board should be able to do so up front. I am affraid it needs to do more so I am looking forward to the next BLE Board!

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1 Solution
Anonymous
Not applicable

Hello Thomas,

Thank you for your comments:

Recommendation for "future" board to replace  BCM92073X_LE_KIT

1) Pin Header : not convenient at all to wire TP6 for SPI CLOCK and TP7  for MISO in the back of the board to be able to configure SPI in MASTER2_P24_CLK_P04_MOSI_P25_MISO

[JT] - Thanks for this input.

2) Default voltage of the board is 1.2 V or so. While it is good as a marketing point of view to sell low power BLE using coin cell, it uis not good enough to power SPI slaves.

[JT] - The default voltage of the next TAG board will be 3.3V.

3) SPI driver in wiced smart is not as good as STM SPI driver today.  WICED WIFI uses STM for SPI and Host MCU.

Using Host MCU for BLE is a good idea but it is not full feature enough to be abke connect with ALL third party devices out there.

I found issues with Analog Device ADC as well as  Linear LTC2983 SPI ADC. All those board are requiring 3.3 V mimimum.

[JT] - Our next board will have a prototyping area to accommodate the ADC you mentioned.

I am not an hardware engineer but just felt the frustration not beeing able to read anything using SPI master interface after the board was modified for 3.3 V.

[JT] - No level shifters are needed.  We will take this into consideration on the next TAG board - Thanks

Finally I noticed that idevice Connected Devices - Bluetooth Module & Product Development | iDevices LLC is using "iDevices Bluetooth Smart Module from Broadcom" as a platform that can simply connect to their favorite CPU/Micro-controller via a UART interface.

It is interesting that they decided to use UART for iGrill  to have BLE communicate with a bigger Host MCU over UART to exchange data back and forth and let the HOST MCU deal with SPI communciation with Thermocouple and ADC. It looked like it confirms that SPI driver is better on STM today. It is too bad because on paper the BLE should be able to drive 4 SPI slave device.

[JT] - The SPI ports can drive 2 slave devices.

If Broadcom want to connect everything then the eval board should be able to do so up front. I am affraid it needs to do more so I am looking forward to the next BLE Board!

[JT] - Coming soon!

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