JeeLink v3 & v3a

The JeeLink is a small module in the shape of a USB stick, with an Atmel ATmega processor and a wireless radio radio module.
Versions v3 and v3a use the Hope RF RFM12B module. The frequency band is set at the factory and marked both on the chip on the radio module (yellow = 868 MHz, green = 433 MHz ) and by with the antenna wire length (868 MHz is 82 mm; 433 MHz is 165 mm).

Note: there was a previous JeeLink version JL1 with a different form factor, as predecessor of what is now the JeeNode USB.

Differences from the JeeNode USB:

  • different form factor, enclosed in a plastic case
  • no pins or port connectors to attach anything to
  • includes 16 Mbit of flash memory (M25P16 8-SOIC), connected via SPI
  • uses a 10 ppm crystal for improved time-keeping accuracy
  • no reset button, no LiPo charger

note: the v3a version made small layout adjustments for manufacturabilty. There are no changes to the schematic

JeeLink v3c

The PCB layout was revised for manufacturability and provision to mount the Hope RFM69CW radio module.
With similar power settings, the RFM69CW radio module has greater range and/or wall penetration success than the RFM12B.

How to Get It

Pre-assembled units and boards are available in the “Shop”
Or create your own boards with the EAGLE files below.
Dimensions: 19 x 49 mm (board), 23 x 71 x 8.7 mm (enclosure)

How to Use It

With RF12demo loaded, you can make a quick test by turning on/off the blue LED with “1l” (1 + lowercase L)/“0l”.
A JeeLink has similar functionality to the JeeNode and JeeNode USB, so have a look at the JeeNode page.

Note: the JeeLink v3 uses the OptiBoot loader, i.e. it’s compatible with an Arduino Uno.

Depending on the USB Port spacing on your laptop/powered hub/RasPi variant, inserting the JeeLink may block physical access to neighbouring USB port(s).
Here is what happens on a recent RasPi release.

There are two solutions:

  • Short term for testing - temporarily remove the plastic cover. The two halves are positively mated, but not glued. With some care, they will separate - the clips are good for several mate/un-mate cycles. The 5V USB power line is exposed on the PCB, a simple plastic sleeve will protect against accidental shorts while testing. Note that the unpopulated ISP header is available to repair damaged bootstraps, adjust fuse settings etc. - though this connection path is rarely used in practice since the bootstrap is pre-programmed in production and checked in final test.

  • More permanent installation - the preferred solution is to use a short Male/Female USB extension cable. For applications trying to pick up remote/weak signals, this has the advantage of moving the JeeLink RF section away from what can be a noisy EMI environment. It is not unusual to see the local RF noise floor lifted 15-20 dB in close proximity to the host.

Cover removed

Photos courtesy of @JeeFan

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