PC Boards for PICAXE Processors
I am pleased to announce a new line of printed circuit boards specifically designed for PICAXE(R) programming with breadboard circuits. Please note that "PICAXE" is a registered trademark of Revolution Eduation, Ltd. The products presented below are not authorized or supported by Revolution Education; they are simply a part of my effort to assist the growing community of PICAXE(R) hobbyists and experimenters.
At the present time, each JRHackett.net board is available only as a bare board. Complete documentation for each board is available on the individual product pages.
Programming Interface Boards
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These two boards greatly simplify the task of setting up the PICAXE programming interface. Whenever you are working on more than one project at a time, it's a simple matter to move the programming interface board from one breadboard to another, keeping your original project intact, without needing to duplicate the PICAXE programming circuitry for each project.
The smaller programming interface board (Prog-05, on the right of the photo) provides the complete PICAXE Enhanced Programming Interface specified by Revolution Education, as well as an LED (which can be disabled) on the "Serial Out" programming pin (output 0 on the PICAXE-08M and PICAXE-14M). The LED provides a simple means to test that the board is functioning correctly. In addition, the LED also flickers during a software download, so it provides feedback that the download is proceding properly. The larger programming interface board (Prog-07, on the left of the photo) includes everything on the Prog-05, as well as a convenient switch that can be easily connected to any PICAXE input pin.
Note: In order for a PICAXE program to run properly, the processor's "Serial In" pin must be tied to ground. The 10k and 22k resistors in the PICAXE programming circuit satisfy this requirement. However, when you remove the programming circuit (as suggested above), the Serial In pin is left floating and your program will not function properly. A 100k resistor connected between the Serial In pin and Ground solves this problem, and I have found that it can even be left in the circuit when the Programming Interface Board is attached without interfering with the programming process.
PICAXE Project Boards
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(Click on any PC board above to view a larger image.)
These four project boards include the same PICAXE Enhanced Programming Interface and LED on output 0 as the above two programming interface boards, and they also include space for an on-board PICAXE chip as well. As an indication of how space-efficient these boards are, all four of them are shown in the above photo installed on one standard 830-point (6.5" x 2.125") breadboard.
If you happen to have 4 serial ports on your PC (and who doesn't? :-) you could actually use the PICAXE Programming Editor Software to simultaneously work on four independent PICAXE programs! While most users would never have the need to do this, it is not unusual to be working on two programs at the same time. For example, you could easily install two of our PICAXE project boards on the same breadboard and develop an infra-red transmitter/receiver project involving two PICAXE chips.
The PICAXE project boards in the above photo are (from left to right), the SIP-18 board (for the PICAXE-18 and -18X chips), the SIP-14 board (for the new PICAXE-14M chip), the SIP-08 board (for the PICAXE-08 and -08M chips) and the Tiny-08 board (also for the PICAXE-08 and -08M chips). All four boards include an LED on the Serial Output pin, and all but the Tiny-08 also include a switch that can easily be connected to any PICAXE input pin.
On each project board, all of the PICAXE I/O pins, as well as V+, Ground and the input switch (if included on the board) are brought out to the SIP connector. This arrangement greatly simplifies breadboard wiring. For example, the SIP-08 board is shown below with a simple three-LED output circuit. Notice how the board's SIP connector simplifies the placement of the current-limiting resistors in the circuit. Compared to the usual set-up (with the PICAXE chip in the center of the breadboard), this arrangement also provides considerably more space for user circuitry on the breadboard.
BreadBoard Power Supply Board
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The above photo also illustrates the use of our breadboard power supply board (BBP-01). This board is used with a 9v to 12v "wall-wart" type AC-to-DC power adapter with a 2.1 mm I.D. and 5.5 mm O.D. (center positive) plug. The BBP-01 board includes a reverse power protection diode, a convenient power switch, a power-on LED indicator and ample filter capacitors to provide a regulated 5v output for your breadboard projects.
As can be seen in the photo, the two breadboard power supply rails are in the same relative position - that is, power is below ground in both the top and bottom rails. (If you position the BBP-01 board on the right side of the breadboard, power would be above ground in both the top and bottom rails.) This arrangement is required for use with the BBP-01 board.
There are a few breadboards on the market that reverse one of the supply rails (e.g., power is on the outside edge on each side of the breadboard and ground is toward the middle of both supply rails. This type of breadboard cannot be used with the BBP-01 board. To do so will reverse the supply lines on one side and could cause considerable damage to your PICAXE chip and other circuitry.
Programming Cable
The two programming interface boards and the four PICAXE project boards all use the same programming cable for connection to your PC. This cable consists of a 9-wire or 10-wire ribbon cable with a female DB-9 IDC connector on the PC end, and a 2x5 female IDC header on the breadboard end, which mates with the male headers on each of our boards. This arrangement was chosen because it enables users to make their own inexpensive cables without needing to solder or crimp individual wires. Directions for constructing the programming cable are presented on the Programming Cable page.
On all of our boards, the programming cables attach to the bottom side of the board so that there is a minimum of clutter on the top-side. This arrangement fits most breadboards available today (for example, see www.pololu.com), which are approximately 2.125 inches wide. There are a few older breadboards that are too wide to fit any of our boards. To be sure that our boards are suitable for use with your breadboard, make certain your breadboard's width is no greater than 2.25 inches before purchasing one of our products. Assembled or partially-assembled boards cannot be returned.