fx2grok

From sigrok
Jump to: navigation, search

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 FX2 eval board / logic analyzer.
  • Optional: Make a tiny "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).

Hardware

  • 13mm x 13mm PCB.
  • Double-sided 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, or through-hole one with bent leads (less PCB space needed, but higher device).
  • No buffer or other 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 and PCB layout is available from the fx2grok git repository:

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

Bill of materials

Qty Device Footprint Size Value Refdes Digikey Mouser Comments
1 Cypress CY7C68013A-56LTXC QFN-56 8mm x 8mm IC1 10.07€ 12.00€ Main chip. Alternatives: eBay: 4.04€ (but who knows if it's fake), Future Electronics: 5.52€
1 Hirose ZX62-B-5PA(11) custom 9.8mm x 5.6mm U1 0.98€ 0.908€ USB Micro-B SMD connector
1 Abracon ABM11-24.000MHZ-B7G-T custom 2mm x 1.6mm 24MHz X1 2.27€ 1.96€ 24MHz crystal
1 Micrel MIC5319-3.3YD5 SOT-23-5 2.9mm x 1.6mm 3.3V U2 1.89€ N/A 3.3V LDO
1 FCI 20021111-00010T4LF custom P1/P2 0.66€ 0.42€ 5x2 through-hole pin header (1.27mm pitch), soldered to the PCB (5 pins per side)
1 FCI 20021311-00010T4LF custom 0.99€ 0.49€ 5x2 connector/receptacle (1.27mm pitch), used for the probe cable
5 Resistor 0402 0.25mm x 0.125mm 2.2 kΩ ... ... ... ...
1 Resistor 0402 0.25mm x 0.125mm 2.7 kΩ ... ... ... ...
1 Resistor 0402 0.25mm x 0.125mm 100 kΩ ... ... ... ...
9 Ceramic Capacitor 0402 0.25mm x 0.125mm 100nF ... ... ... ...
2 Ceramic Capacitor 0402 0.25mm x 0.125mm 1uF ... 0.071€ 0.083€ ...
3 Ceramic Capacitor 0402 0.25mm x 0.125mm 2.2uF ... 0.11€ 0.066€ ...
2 Ceramic Capacitor 0402 0.25mm x 0.125mm 12pF ... ... ... ...
1 LED 0402 0.25mm x 0.125mm ... ... ... ...

Resources