RFX Teensy 3.x/LC dev board w/ shield breakout, prototyping area, nRF24L01+ (Kit)
RFX Teensy 3.x/Teensy LC development board with Arduino shield breakout, prototyping area and nRF24L01+ headers. Easy assembly using all through-hole components, so no advanced soldering skills or equipment required!
This Uno-sized (7cmx5cm) carrier board for PJRC Teensy 3.0/3.1 is a convenient way to add nRF24L01+ module and Arduino shield compatibility to a Teensy 3.x project, as well as providing a general breakout board with prototyping area.
All Teensy pins are broken out on headers, including (optionally) the “pads” for additional digital pins D24-33, and analog pins A12-13, on the underside of the 3.0/3.1 boards (note: LC board doesn’t have these pads). Access to these pads is via a 2×7 male SMT pin header plugging into a matching 2×7 low profile through-hole female header. Note that Paul Stoffregen, the designer of the Teensy boards, advises that these pads aren’t really strong enough to sustain frequent plugging/unplugging, so care will be required if using this option. (See here.) The other simple option for access to these pads, if required, is fixed wiring (e.g. flexible hook-up wire to the proto area).
Carrier board has two 8 pin (4×2) headers for plugging in a nRF24L01+ module, one header providing connection to the hardware SPI pins D11-D13, and the other to an alternative set of pins, D4-D6, for a software SPI (“bit banging”) implementation if preferred. IRQ pin is set at D2, CE is D3 and CSN is D7.
Also has provision for a 3×2 connection header to the ICSP hardware SPI pins, which is required if accessing hardware SPI by some shields.
Power can be supplied by 5V micro USB connection directly to Teensy, either from a “phone charger” style power supply with a micro USB connector, or USB connection to a computer. This will also power the external 3v3 voltage regulator, with a limitation of 500mA supply (poly fuse in the Teensy limits the supply current.) 5v to the 5V pin on the power header is also provided in this configuration.
Alternatively, the 3v3 regulator can be powered directly by e.g., the DC barrel jack connector mounted under the Teensy (standard 5/2.1mm size — see photo). This has the advantage of bypassing the 500mA poly fuse limitation, if you need higher current available on the 3v3 rail. (Note that the Teensy is powered from the main 3v3 rail on this board, so it not necessary to power the Teensy via the micro USB connection — you just need to get power to the external regulator.)
Supplying 3v3 directly to the rail via a well regulated 3v3 supply is also an option, of course, eliminating the need for the 3v3 regulator. And the prototyping area gives flexibility for many more possible configurations!
The carrier board supports the standard Arduino shield header layout, as well as a second breadboard compatible (i.e., proper 0.1″ pitch grid-aligned) header layout, so you can also easily connect the board to breadboards, or common 50mm (or wider) proto boards.
For many shields, a set of stackable headers will have to be used for the shields to clear the height of the Teensy (which is mounted at the same level as a shield). So a set of stackable headers (available as a kit option) is recommended if deploying shields is a consideration.
The other advantage of using the stackable headers with shields (even those that would clear the placement of the Teensy) is that they also allow clearance for a nRF24L01 module if mounted on the board headers. (Refer to photos.)
So lots of flexibility and configuration options with this carrier board! Combined with the generous prototyping area, this can make deploying of nRF24L01+ enabled projects using a Teensy 3.x faster and neater.
Photos show populated board with Teensy 3.x, with and without Arduino shield mounted on stackable headers (Teensy 3.x and shield not included, shown for demonstration purposes). Shown beside Arduino Due and Leonardo for scale.
Available as bare PCB, or PCB with basic kit components (headers, caps, voltage regulator, etc.)
A set of stacking headers is an optional add-on, to provide additional height clearance for shields, as described above.
Another kit add-on is a set of “long pin” male header “gender changer” headers for breadboard connectivity via the secondary grid-aligned headers. (To see how these are designed to work, review this thread. Specifically, reply #7. I’m describing a different RFX board, but the breadboarding set-up described using the grid-aligned headers applies equally this carrier board.)
If connectivity to underside pin “pads” is required for a 3.0 or 3.1 board, a 7×2 SMT pin header and low-profile socket set is available as an option (not required for an LC board — no underside pads!) Note: The SMT pin header is a surface mount component; otherwise all components in the kit are through-hole. (Much easier to mount the SMT pin header on the Teensy before the through hole pin headers are attached.)
Finally, a low or high-power nRF24L01+ radio module can also be added as a kit option.
Note that in kits, female pin headers supplied in 40-pin strips that need to be cut to length (all instructions supplied). Additional strip included in case of goofs!
Basic kit parts (BOM)
1 PCB mount 5mm/2.1mm DC barrel jack (see note below)
1 1N5817 Schottky diode
1 0.1uF cap
1 10uF cap
1 2x3 header (m)
2 2x4 headers (f)
1 1x5 headers (f)
1 1x13 " "
1 1x14 " "
2 1x6 " "
2 1x8 " "
1 1x10 " "
Note: For the latest version of the board, provision has been made for a PCB mount DC “barrel” power jack can be mounted under the Teensy as an option. The part required is a standard 5mm/2.1mm 3 tab barrel jack, modified to remove the side tab, leaving two tabs used to mount the part. See the additional notes at the end of the assembly notes for more details.