Difference between revisions of "BBB-GVS"

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* 3.3V and 5V power status LEDs
 
* 3.3V and 5V power status LEDs
 
* Beaglebone Black form factor
 
* Beaglebone Black form factor
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 +
== Technical Overview ==
 +
 +
In a nutshell, the 3.3V digital signals of the Beaglebone Black need to be changed into 5V digital signals. There are a number of discrete ways to convert 3.3V bus to 5V signals. Some of them use MOSFETs and a couple of resistors. These work OK but there are some powerful chips out there that can do the conversion even better. We looked around and found what we think is the best 3.3V<>5V data conversion chip, Texas Instrument's TXS0108. The TXS0108 is an 8-bit, bi-directional buffer with automatic direction detection. Each and every pin can transmit and receive independently and even at the same time. The part supports both open drain and push-pull operation. The part can run as fast as 60 Mb/s in push-pull operation and 2 Mb/s in open drain. This speed is fast enough enough for microprocessor GPIO pin or even the fastest serial interfaces that a microprocessor can throw at it.
  
 
== Assembly Sheet/Parts List ==
 
== Assembly Sheet/Parts List ==
  
 
* [[BBB-GVS Rev X4 Assembly Sheet]]
 
* [[BBB-GVS Rev X4 Assembly Sheet]]

Revision as of 11:42, 25 January 2020

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BBB-GVS-X4-CCA-001-640.jpg

Beaglebone Black cape which provides 5V GVS connections

We love the Beaglebone Black. With all of its I/O connections it offers exciting potential for embedded/connected devices. It even has real mounting holes which let the board be used for real-world applications.

When we got our first Beaglebone Black we were excited to try it with some of our Arduino GVS (Ground/Voltage/Signal) sensors and GVS output devices but couldn't since they are all 5V sensors. Sure we could cobble together some level shifters on a breadboard but in the end we wouldn't have something that could be deployed in a real application What we really wanted was a 5V Sensor shield like the one we use for our Arduino. But there were none out there. So we designed one.

Introducing the BBB-GVS cape.

Features

  • (5) 5V GPIO GVS connections (auto direction detection)
  • (4) 5V GPIO/Timer GVS connections (auto direction detection)
  • (2) 5V UART Tx/Rx connections (auto direction detection)
  • (1) 5V PWM GVS connection
  • (1) 5V I2C bus 4-pin connections (auto direction detection)
  • 5V pins are all ESD protected pins with 15 kV of protection
  • Cape configuration EEPROM
  • (7) 3.3V GPIO connections
  • (1) 3.3V UART Tx/Rx connection
  • (1) 3.3V PWM GVS connection
  • (7) 1.8V analog GVS connections
  • Resettable Fuses on 5V and 3.3V power
  • Selectable 5V source
  • 3.3V and 5V power status LEDs
  • Beaglebone Black form factor

Technical Overview

In a nutshell, the 3.3V digital signals of the Beaglebone Black need to be changed into 5V digital signals. There are a number of discrete ways to convert 3.3V bus to 5V signals. Some of them use MOSFETs and a couple of resistors. These work OK but there are some powerful chips out there that can do the conversion even better. We looked around and found what we think is the best 3.3V<>5V data conversion chip, Texas Instrument's TXS0108. The TXS0108 is an 8-bit, bi-directional buffer with automatic direction detection. Each and every pin can transmit and receive independently and even at the same time. The part supports both open drain and push-pull operation. The part can run as fast as 60 Mb/s in push-pull operation and 2 Mb/s in open drain. This speed is fast enough enough for microprocessor GPIO pin or even the fastest serial interfaces that a microprocessor can throw at it.

Assembly Sheet/Parts List