Difference between revisions of "Fx2grok"

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=== Cable and connector variants ===
=== Cable and connector variants ===
'''Samtec SFSD-05-28-H-10.00-SR + TFM-105-01-L-D''':


<gallery>
<gallery>
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File:Fx2grok_samtec_cable_connected.jpg|<small>Cable connected</small>
File:Fx2grok_samtec_cable_connected.jpg|<small>Cable connected</small>
File:Fx2grok samtec cable pinheader.jpg|<small>Cable + pinheader</small>
File:Fx2grok samtec cable pinheader.jpg|<small>Cable + pinheader</small>
</gallery>
'''Hand-soldered ribbon cable''':
<gallery>
File:Fx2grok ribbon cable orig.jpg|<small>Ribbon cable</small>
File:Fx2grok ribbon cable wires.jpg|<small>Individual wires</small>
File:Fx2grok ribbon cable soldered.jpg|<small>Soldered connector</small>
File:Fx2grok ribbon cable conn kapton.jpg|<small>Kapton tape</small>
File:Fx2grok ribbon cable finished.jpg|<small>Finished cable</small>
File:Fx2grok ribbon cable comparison.jpg|<small>Cable comparison</small>
</gallery>
</gallery>



Revision as of 23:35, 14 September 2017

The fx2grok device is intended to be the tinyiest possible Open Hardware FX2 eval board (that can be used as 8-channel logic analyzer).

The schematics and layout are done from scratch in Kicad, and are released under the CC-BY-SA 3.0 license.

Using the open-source fx2lafw firmware (and sigrok, of course) you can use this device as 8-channel logic analyzer.

Goal

  • Make the tinyiest-possible Open Hardware Cypress FX2 based 8-channel logic analyzer.
  • Optional: Make a tiny 3D-printed enclosure, and/or an "enclosure" using resin (example) with the device (including probes) ideally looking similar to the sigrok logo in the end.

What is NOT the goal?

As you may know, there are tons of FX2-based logic analyzers (and tons of clones) already. There's not much use in creating yet another "standard" device.

The goal of this little hobby project is thus NOT to make a better device, or to make a cheaper device, or anything like that. The only goal is to have it as tiny as possible (it's more of a "just for fun" project).

Status

Work in progress, untested, may or may not work!

First PCB, fx2grok-tiny 0.1, is finished and test boards are ordered. Whether or not everything works as planned is yet to be seen.

Hardware

  • 13mm x 13mm PCB
    • 0.8mm PCB thickness, 5mil traces, 6mil trace clearance, 8mil via drill hole diameter, 5mil annular ring.
  • Double-sided 2-layer PCB/layout, 0402 SMD components soldered on both sides.
  • USB micro-B connector.
  • 1.27mm 5x2 pin header.
  • FX2 in 56pin QFN package.
  • Small SMD 24MHz crystal.
  • No buffer or other input protection (not even 100 Ω resistors for each probe).
  • No EEPROM, the device will enumerate with the standard Cypress FX2 "unconfigured device" USB VID/PID (04b4:8613).

Download

The schematics, PCB layout and Gerber files are available from the fx2grok git repository:

$ git clone git://sigrok.org/fx2grok

Photos

Schematics, PCB layout, 3D preview

Cable and connector variants

Samtec SFSD-05-28-H-10.00-SR + TFM-105-01-L-D:

Hand-soldered ribbon cable:

Bill of materials

Note: All prices are for single quantities, most parts get a lot cheaper if you buy higher quantities.

Qty Device Footprint Size Value Refdes Digikey Mouser Comments
Required parts
1 Cypress CY7C68013A-56LTXC QFN-56 8mm x 8mm IC1 10.05€ 10.30€ Main chip. Alternatives:
1 Amphenol FCI 10118192-0001LF custom 9.8mm x 5.6mm U1 0.38€ 0.35€ USB Micro-B SMD connector
1 Murata XRCGB24M000FAN00R0 custom 2mm x 1.6mm 24MHz Y1 0.29€ 0.46€ 24MHz crystal
1 Micrel MIC5504-3.3YM5-TR SOT-23-5 2.9mm x 1.6mm 3.3V U2 0.10€ 0.10€ 3.3V LDO
4 Yageo RC0402JR-072R7L 0402 0.25mm x 0.125mm 2.7 kΩ R2, R3, R4, R5 0.08€ 0.08€ Resistor
1 Samsung RC1005J104CS 0402 0.25mm x 0.125mm 100 kΩ R1 0.08€ Resistor
8 Samsung CL05A104KP5NNNC 0402 0.25mm x 0.125mm 100nF C2, C5, C7, C8, C10-C13 0.08€ Ceramic capacitor
3 Taiyo Yuden JMK105BJ105KV-F 0402 0.25mm x 0.125mm 1uF C1, C14, C16 0.08€ 0.10€ Ceramic capacitor
2 Murata GRM155R61A225KE95D 0402 0.25mm x 0.125mm 2.2uF C3, C6 0.08€ 0.08€ Ceramic capacitor
2 Samsung CL05C120JB5NNNC 0402 0.25mm x 0.125mm 12pF C4, C9 0.08  Ceramic capacitor
1 Vishay VLMB1500-GS08 0402 0.25mm x 0.125mm D1 0.34€ 0.51€ LED
Optional parts / variants
1 Amphenol FCI 20021111-00010T4LF custom P1/P2 0.53€ 0.55€ 5x2 through-hole pin header (1.27mm pitch), could soldered to the PCB (5 pins per side)
1 Amphenol FCI 20021311-00010T4LF custom 0.68€ 0.69€ 5x2 connector/receptacle (1.27mm pitch), could be used for soldering the probe cable/wires
1 Samtec TFM-105-01-L-D custom P1/P2 0.53€ 5x2 through-hole pin header (1.27mm pitch) with a notch, soldered to the PCB (5 pins per side), match for the Samtec SFSD-05-28-H-10.00-SR cable below
1 Samtec SFSD-05-28-H-10.00-SR custom 4.77€ Potential probe cable, needs some crimping

Note: C15 is missing and there is a C16, which is correct. C15 was removed and the numbering wasn't reset.

Resources