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Wisp 4.1 DL (Hardware)
WISP Firmware Info
RFID Verilog Code
Impinj Reader (Browser)
Impinj Reader (LLRP)
SVN Repository Access
Passive Data Logger
WISP 4.0 DL
Gen 1 Hardware
VB.NET Reader App
VB6 Reader App
Impinj Reader (SDK)
HW Feature Set
Adding A Sensor
Using the EEPROM
Sending Data to WISP
Gen2 Physical Layer
Gen2 Link Layer
RF FE Measurement
HW How To - FAQ
Hardware How to and FAQ
This page discusses many of the common '
questions related to WISP hardware
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
For hardware issues, see
For firmware issues, see
For RF Front End issues, see
WISP RF FE Measurement Procedures
& Discussion Board Archives
USB Debugger Power vs. WISP Power
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
Adding a sensor
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:
Somewhat bulky, lower density but relatively low leakage and low cost
These have good density but high leakage (50uA to 150uA).
We've used this 1000uF part:
However, they have newer 1000uF offerings such as:
And higher density / higher leakage 2200uF such as:
0.1F Kanthal MaxCap LX Series (
) - 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
and we can make arrangements to modify your hardware.
The last modification was made by
on Sep 22, 2010 5:08 pm
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