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Hardware How to and FAQ

This page discusses many of the common 'how to' questions related to WISP hardware
Questions? - alanson alanson and - yeagerd yeagerd maintains this page.

First Things First

If you are going to do anything with the WISP hardware you need to familiarize yourself with the schematics and layout.

Next familiarize yourself with the general operation of the WISP
Design of an RFID-Based Battery-Free Programmable Sensing Platform.pdf

Debugging Tutorials

For hardware issues, see Debugging Hardware.
For firmware issues, see Debugging Firmware.
For RF Front End issues, see WISP RF FE Measurement Procedures.

General Questions

& Discussion Board Archives

USB Debugger Power vs. WISP Power

Oscilloscope Recommendation

Is the Regulator Required?

The MSP430 Input Pins are Sinking Current

Where is the EEPROM Code?

Troubleshooting the USB Debugger

Measure / Test the RF Front End

Probing and Measuring the WISP

How to measure rectified voltage
The rectified voltage can be measured on the Vout pin. See schematic and layout documents. Wisp 4.1 DL

Hardware Modifications

Adding a sensor
The WISP Hardware Features page has a section on unused pins for external sensors. There is also a tutorial on Adding A New Sensor.

Adding a super capacitor
WISP doesn't ship with a supercap by default. Its easy to install - just solder a large electrolytic, tantalum or super capacitor into the two big thru-holes on the WISP.

Example of a 0.1F super capacitor installed on the WISP4.0
The WISP4.1 has been designed to receive a Kanthal 0.1F super capacitor. The two large through holes (lighted in red) are connected to gnd and the Vout through a 100ohm resistor, please review the schematics and layout for details.

If you want to do it yourself (the fastest way):
Make sure the cap you order can handle at least 6V and make sure to get the polarity correct. Some parts links:

  • Electrolytic Cap
  • Somewhat bulky, lower density but relatively low leakage and low cost
  • Tantalum Cap
  • These have good density but high leakage (50uA to 150uA).
  • Super Cap
  • 0.1F Kanthal MaxCap LX Series (Manufacturer Site) - Have to order direct. We have a bunch, and we'd be happy to send you some.

If you aren't comfortable soldering:
Send a message to - yeagerd yeagerd and we can make arrangements to modify your hardware.

The last modification was made by - yeagerd yeagerd on Apr 26, 2012 9:28 am

hw_how_to_-_faq.txt · Last modified: 2018/07/11 08:25 (external edit)