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Wearable Raspberry Pi – Some Adjustments

USB Hub
USB Hub

As the first USB hub I was using was certainly not stable – it would not enumerate between boots & to get it working again would require waiting around 12 hours before applying power, it has been replaced. This is a cheapie eBay USB hub, of the type shown below.

These hubs are fantastic for hobbyists, as the connections for power & data are broken out on the internal PCB into a very convenient row of pads, perfect for integration into many projects.

Breakout Hub
Breakout Hub

I now have two internal spare USB ports, for the inbuilt keyboard/mouse receiver & the GPS receiver I plan to integrate into the build.

These hubs are also made in 7-port versions, however I am not sure if these have the same kind of breakout board internally. As they have the same cable layout, I would assume so.

 

Connector Panel
Connector Panel

Here is a closeup of the back of the connectors, showing a couple of additions.

I have added a pair of 470µF capacitors across the power rails, to further smooth out the ripple in the switching power supply, as I was having noise issues on the display.

Also, there is a new reset button added between the main interface connectors, which will be wired into the pair of pads that the Raspberry Pi has to reset the CPU.
This can be used as a power switch in the event the Pi is powered down when not in use & also to reset the unit if it becomes unresponsive.

 

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Wearable Raspberry Pi Part 1.75

USB Hub
USB Hub

The hub for the external USB ports has been fitted here, with the two ports hardwired to the pads where once there were USB A sockets. This hub will also accommodate the wireless receiver for the mini keyboard & mouse, in the remaining port that will sit between the external USB ports.

USB Ports
USB Ports

In this gap between the ports is where the wireless receiver will sit for the keyboard & mouse, the pair of screws securing the external ports in the centre have been shortened to make more room.

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Wearable Raspberry Pi Part 1.5

USB Ports
USB Ports

For convenience, a pair of USB ports have been fitted to the wearable Pi, which open on the bottom of the unit. These will be hardwired into a 4-port USB hub which will also support the wireless adaptor for the mini-keyboard that is to be used with the device.

USBs
USBs

The two USB ports on the bottom of the casing.

External Connections
External Connections

The external connectors are also complete. The audio jack & second WiFi antenna port are fitted.

The audio is normally routed to the LCD display speaker, until a jack is plugged into the 3.5mm socket.

 

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Belkin 2 Port KVM Switch

Main Body
Main Body

Here is an old type KVM switch, PS/2 & VGA interface.

Label
Label

Details Label

Top Removed
Top Removed

Top removed from the main body, the cables coming in from the bottom connect to the VGA, keyboard & mouse ports on the slave computers, the connectors at the top connect to the single monitor, keyboard & mouse.

PCB
PCB

PCB removed from the body. This is driven by a PIC16C57C-04 microcontroller.
The pair of LEDs indicate which computer is using the peripherals at any one time.