From Random Projects
Jump to: navigation, search
Floss-JTAG 1.0 adapter
Floss-JTAG 0.2 front
Floss-JTAG 0.2 back
Floss-JTAG 0.2 adapter
Floss-JTAG 0.2 adapter

Floss-JTAG is a small Open Hardware USB JTAG adapter for 3.3V targets, designed by Piotr Esden-Tempski.

Schematics and PCB layouts are licensed under the CC-BY-SA 3.0 license.


The latest schematics, PCB layouts, are available from GitHub:

$ git clone git://github.com/esden/floss-jtag.git


  • Floss-JTAG is a tiny board (34.5mm x 17mm) with mini USB and Molex picoblade(TM) connectors.
  • It uses the FT2232H USB-to-serial chip.
  • The original target is Open-BLDC and Openmulticopter but it can also be used for all other 3.3V targets.

Software used

  • The board was designed with Eagle PCB software (for commercial use of the Floss-JTAG design a commercial license of Eagle has to be purchased).
  • OpenOCD includes the necessary configuration file (flossjtag.cfg and flossjtag-noeeprom.cfg) and support to use Floss-JTAG for programming and debugging targets.

Further resources

Parts list

Quantity Device Footprint Value Refdes Comments
1 FT2232HL LQFP64 IC1
1 1117 V-Reg SOT223 3.3V IC2
1 Molex Picoblade 8Pin 53261-08 JTAG
1 Molex Picoblade 4Pin 53261-04 X2
1 Micro USB Conn UX60A-MB-5ST X3
1 Quarz NX3225SA 12MHz X3
1 Green LED 0603 Green LED1
1 Red LED 0603 Red LED2
11 Ceramic Capacitor 0603 100nF C1, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12
2 Ceramic Capacitor 0603 27pF C15, C16
1 Tantal Capacitor 3216/A 3.3uF C2
2 Tantal Capacitor 3216/A 4.7uF C13, C14
1 Resistor 0603 1k R1
1 Resistor 0603 12k R2
2 Resistor 0603 220 R3, R4
2 Ferrite Bead 0603 600Ohm 500mA L1, L2

Where to buy

The hardware is now also available for purchase from the Joby Robotics shop: