Home Modifications Tshow Part 2 – Processor Module

Tshow Part 2 – Processor Module

by Moderator
Processor Module Parts List

1 – Uxcell Battery holder for CR2032 Cell (10 pcs)
1 – Lithium-Ion Battery, CR2032
1 – Electrolytic Capacitor, 1000 uF, 10v
1 – Diode 1N4004
1 – LED, T1, Blue
2 – 75176AP, Differential Bus Transceivers
1 – RJ12 Jack, Low-profile 6-Pin
1 – Molex 12-Pin Connector, Male, #34691-0120*
1 – Adafruit Bluetooth Module, BLESPI, with male headers
1 – Adafruit CPU Module, Teensy 3.6, with male headers
5 – Short female headers on 0.1” centers, 36-pin (will cut to size)
2 – SN65HVD230, Can Bus Transceiver Module, with male headers
1 – CPT 12 VDC to 5 VDC Converter, 15W
1 – TXB0104, 4-bit Level Translator Module
1 – P27P06, P-channel MOSFET 60V, 27A
1 – Resistor, 10K ohms, 1/4W
1 – Resistor, 47 ohms, 1/4W
1 – Grayhill Pushbutton SPST, PCB mount, #38FSP9B9M6RT*
1 – Tshow Mainboard, Printed Circuit Board (zip file, Gerber)
1 – Hammond Plastic Case, 1555F2F17GY*
1 – Paper adhesive label, 3.4” x 3.2”
4 – Screws to mount PCB to the enclosure
2 – Screws, 3/8″, self-tapping, to mount CPT DC-DC converter to PCB
4 – Velcro squares 1” x 1” or similar
4 – Double-sided carpet tape, cut to 1”x1” square

* available from Mouser Electronics

tshow processor parts

Processor parts before assembly

Processor Module

Using the Tshow mainboard, assemble and solder all the parts. I started with the DC/DC converter, using two 3/8” long self-tapping screws to hold it in place.

On some parts, such as the Teensy CPU board, I soldered male headers on the Teensy and used female headers on the PCB. You’ll need two 24-pin headers for the long sides of the Teensy, and the 5-pin header near the Teensy program button. The extra 9 holes near the USB connector are not used. The Bluetooth module will need a male header, with a female header on the PCB to provide clearance for the IC under the module.

The female headers are probably not necessary, but it makes debugging far easier if something is not working right. The LED should be side mounted so it will poke out from the enclosure in the same direction as the reset button.
On the CAN bus modules, you need to remove the 120-ohm surface mount termination resistor. You can desolder it, or perhaps break it off with longnose plyers. The Tesla CAN bus already has the necessary termination resistors.

Assembled Processor PCB

Assembled Processor PCB

In hindsight, I should have designed a 3D box for the processor module, but instead, I used an off-the-shelf grey plastic box that requires some modifications and holes. The project also used some PCB modules that basically are just a surface mount chip. This avoids having to solder a surface mount chip to the PCB. The cost difference is negligible but does require some additional soldering.

I mounted the completed PCB assembly at the top of the box (without flanges). You’ll need two holes for the reset button and LED. Two rectangular holes are needed for the two connectors. I also made a partial opening for the USB port so I could load new software when the case is open.

The bottom of the grey box will need a partial cut for the smaller connector. The larger connector needs a much larger cut, including part of the mounting tab, needs to be cut away. Most of these cuts I made with a table saw, which makes for a clean cut. I’m sure there are other ways to do this work.

This processor module label can be printed on adhesive paper and cut to fit the indent on the top of the plastic box.

Processor Module Label

Processor Module Label (click for full size)

The box is screwed together with four screws, included with the box.

Completed Processor Module

Completed Processor Module

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Megabyte 18-Jun-2021 - 12:43 am

Am I missing a link to download the Tshow Mainboard, Printed Circuit Board to be sent to one’s favourite PCB fabricator?

Moderator 18-Jun-2021 - 9:00 am

Now included in the parts list.

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