For Mistake Reporting, Ideas or Questions about this information PDF file, you can. or you can post a message at. me at

Transcription

1

2 Note: These are just the electronic control for these devices, no mechanical connection ideas are included for connecting servos to doors or holoprojectors. For Mistake Reporting, Ideas or Questions about this information PDF file, you can me at or you can post a message at AstromechFactory Astromech.net

3 o o RESET L930 B A PICAXE8 Out Prog Red Blk V V

4 What is the Picaxe System? The Picaxe is a Microcontroller system which is programmed from your computer with simple programming system to tell the board what you want it to do. The programming uses simple commands such as: Servo 1,150 In this case the command is telling the servo connected to pin 1 to move to position 150. Simple huh? Why Use Picaxe? There are a number of reasons for using the Picaxe System some of them include - * Quite cheap * Boards already assembled (always a plus) * Very flexible since YOU program what you want them to do. Where Can I Get Them? The Picaxe systems are available online from the following places - USA - SparkFun: UK - Rev-Ed: Australia - Microzed: NOTE: A Picaxe 18X Power board is available but it is mostly for powering small motors up to 1.5amps so not needed for projects included here. How Much? The following starter pack I have found most useful for Astromech use - Picaxe 18X $4.95 USD (SparkFun) Inc Vat (Rev Ed) $50.70 AUSD (Microzed) Price includes Board, Picaxe Chip & Programming Software CD. Price for Rev Ed and Microzed also includes programming cable. Programming cable sold separately for SparkFun packs: Programming Cable - Serial $6.95 Programming Cable - USB $5.95 The cheaper serial cable is sufficient and the only reason you would need the USB cable is if your computer does not have a serial port. A slightly cheaper option is to buy the board and the chip only, as well as the download cable. The software can be downloaded from the Rev-Ed site for free (it is around a 33mb download). If you are buying multiple Picaxe systems, or buying ext ra Picaxe systems after the starter pack, you are better off buying this way. One potential problem with the Picaxe 18 board is that it doesn t have any mounting holes, how you get around this is up to you. But a number of ideas include slots to slide the board in your Astromech or putting the board in a plastic container and attaching the container to the frame. Other Picaxe chips and board combinations are available, such as Picaxe 8M and Picaxe 14M, but they are slightly more limited and they are supplied as a kit which you must solder together. I for one would rather have a fully assembled board. Also the price difference with the 14M and the 18X is not much, so the convenience of an already assembled board makes it a good buy.

5 When you first startup the programming editor you will see this startup screen to select your options. The only critical option you must change is the Picaxe Mode option to the type of chip you are using. We will be using the 18X. When you are happy with your program and wish to run it on the Picaxe system simply plug in the programming cable, and make sure the Picaxe has power. In the menu select PICAXE > RUN and your program will be downloaded to your Picaxe. Change Mode to the type of Picaxe chip you have After you click on the OK button you get to the programming editor. Type in your program, such as below: There are over fifty commands in Picaxe Basic so the PDF Datasheets on the Rev-Ed site should be printed out and studied if you want to get the most out of your Picaxe system. The most important are: Picaxe Manual - Basic Commands Picaxe Manual 3 - Electronic Interfacing Circuits Other PDF Datasheets are also important, such as the datasheets for the individual boards etc. Programs are presented as shown to the right and are to be typed into the programming editor main: Readac 1,b0 Debug b0 Goto main

6 Simulated buttons When you have typed up a program and want to try it without actually downloading it to a Picaxe chip you can use the built in simulator. Just press the yellow triangle and a the simulator screen will load and start. It will step through your program line by line and any outputs going high will highlight in green, and you can push the on screen buttons to simulate a button press on your Picaxe system Please note when programming any Picaxe system, byte and word variables use the same area. So for example if you are using W0, don t use B0 or B1. Simulated Outputs Variables Display W0 = B0 & B1 W1 = B & B3 W = B4 & B5 W3 = B6 & B7 W4 = B8 & B9 W5 = B10 & B11 W6 = B1 & B13 Change for byte or word variables displayed

7 By far the easiest way to try out the projects described in this booklet is to use a breadboard. Any changes to the circuit require no soldering, far better when trying things out. The following items are needed: * Picaxe Chip * Breadboard * k Resistor * 10k Resistor * 4.7k Resistor * 3.5mm Stereo Line Socket * Assorted single strand hookup wire That s all that is needed to get the Picaxe chip running. Of course you will need the items described in the following projects to get individual projects running. Such as LED s, Servo s, extra resistors etc. Below is a typical breadboard, although you can get many different types, too large is better than too small. When you unscrew the black plastic cover there will be three connection points. Solder different coloured single strand hookup wire to the three points. I have used blue, green and yellow here. In the picture below, the middle large connector is at the top: Sparkfun, Microzed and Rev-Ed also also sell a breadboard adaptor. At Sparkfun they are $4.95. You will have to solder it together, but it replaces the 3.5mm stereo line socket, as well as the 10k and K resistors in the download circuit on the next page. The breadboard adaptor looks like this - To plug your download cable in you will need to make up a connector from a 3.5mm stereo line socket. It has to be a stereo, not mono socket such as below. You will also need a power source. Anything from 4.5v to 5.5v DC. You might use 4 rechargeable batteries, or a plug pack that outputs 5v DC.

8 Below is all you need to get the Picaxe18 chip working on a breadboard 5V 0V Below is the position of the input and output pins. Remember outputs 0-7 and inputs are 0, 1,, 6, 7. Whether you use the above download circuit or buy the Breadboard Adaptor, you will still need the 4.7k resistor (in some places it is written as 4K7 - they mean the same thing). Without the 4.7k resistor, which is connected to the reset pin, it will not work. The Picaxe Manual 3 - Microcontroller Interfacing Circuits, available on the Rev-Ed site contains many simple circuit ideas to try, including servos, switches & leds. Once you get the hang of the breadboard you can try the circuit ideas presented in this booklet and without soldering and unsoldering wires every time you want to change the circuit or try a new idea. Input Serial Out Serial In Reset 0V Output 0 Output 1 Output Output 3 Input 1 Input 0 Input 7 Input 6 +V Output 7 Output 6 Output 5 Output 4

9 Below is the hookup diagram for flashing led s. The Picaxe on it s own can only output 0ma per output pin, so if you want to try a string of led s on a single output you need to put the ULN803A chip on the Breadboard. The string of led s is mentioned in the logic display section. The ULN chip can be a bit tricky, because unlike the led circuit below you must connect the output of the Picaxe to the ULN chip and then from the ULN to 5V, not 0V. 330R 5V 0V The only items added to the standard download circuit on the previous page is a 330R resistor, a led and a short wire link. The LED is connected to output 6 in the above. A simple program to flash the led on and off would be: Anything the standard Picaxe 18x board can do, you can also do on the breadboard. Everything from servos, leds, CF music system, switches etc. You will find it much easier to try new ideas and programs when you don t have to get your soldering iron out to change the circuit. main: high 6 wait low 6 wait goto main led on wait seconds led off wait seconds go back to start

10 8M Starter Pack - including board, Picaxe 8M chip & serial download cable. The Picaxe 8M pack is sent as a bag of parts that must be soldered together by you to get working. As you can see from the picture, there is not much to solder so if you have any soldering experience it should not take long at all. Sparkfun $14.95 Rev-Ed 9.79 Microzed $33.75 Sparkfun pack does not include the download cable, and must be purchased separately. The Picaxe 8M board includes a small area to solder extra parts such as resistors, leds etc. The Picaxe 8M is different to all other Picaxe chips, except for the new X range in that some pins can be configured for either input or output. 0 - Output only 1 - Input/Output - Input/Output 3 - Input Only 4 - Input/Output So you could have 4 Outputs and 1 Input or 4 Inputs and 1 Output, or anything in between. Because of the cheapness of this board and chip, it would make it ideal for the PSI s in the dome, although keep in mind the outputs are only capable of 0ma each. To program the 8M, the small jumper must be moved to the program position, and then moved back to use output 0, since they both use the same pin. If your circuit doesn t use Output 0, in can be left in the program position, or all three pins can be connected together permanently so that you don t have to switch back and forward all the time. If you use this board for the PSI for example, and connect the three pins together, the led on Output 0 will simply flash when you are downloading a program. Out Prog Red Blk V V G G Out Prog Red Blk Program Position Output 0 Position

11 Sparkfun - $4.95 USD Rev-ED Inc Vat Microzed - $50.70 AUSD Price includes Board, Picaxe Chip & Programming Software CD. Price for Rev Ed and Microzed also includes programming cable. Programming cable sold separately for SparkFun packs: Resistor Positions for Digital Outputs Programming Cable - Serial $6.95 Programming Cable - USB $5.95 Cut of this resistor to separate the power supplies. Above, Inputs are marked in BLUE, Outputs are marked in RED. Please note - Inputs 0 and 1 are analogue inputs, to use these as digital inputs, such as for switches etc, 10K resistors have to be fitted in positions R7 & R8. To use higher voltages than 5V that the Picaxe uses, the power supplies have to be separated, by removing the resistor shown, then 1V can be used for Logic displays etc. Please note the Picaxe 18X has Inputs 0,1,,6,7 and Outputs 0-7. Inputs 3-5 even though shown on the board, are not used for the Picaxe 18X. Picaxe Power 5V Power for LED s

12 A Picaxe 8X Board is pictured below with inputs and outputs marked. Please note that newer Picaxe 8X1 and Picaxe 8X chips are now available as well. The Picaxe 8X chip has - 8 x Outputs 8 X Inputs The smaller chip next to the Output pins is the ULN803A, the same as the 18X board, and it can be replaced with the Resistor DIL Pack the same as the 18X board for servo use. Also with the outputs you can see that their is a row of holes next to the pins, if you solder a row of header pins you can plug your servos directly on the board as previously mentioned. 4 x Analogue Inputs Inputs Analogue Inputs RESET L930 o o B A Outputs o o Solder Pin Header here Servos Plugged in as follows: Black Wire (0V) Red Wire (power) White Wire (Signal) With this board you can also separate the power supplies as with the 18X, this time you do not remove any resistors, just remove the jumper link at the bottom right corner of the board, and use the pins there as your external power as shown below. PICAXE8 Prices: Sparkfun: $37.95 Rev Ed: 1.87 Microzed: $77.00 Starter pack includes Board, Picaxe 8X Chip & Software CD. As always with Sparkfun, cable sold separately, the prices for Rev Ed and Microzed include Serial download cable, and the pack with USB cable is more expensive. Power Jumper Voltage for Servos etc 0V

13 The Picaxe random command is not explained very well in the manual, and as it can be very handy for Astromech use, I thought I would explain it in more detail here. W1 should change continuously with your random number, hopefully in the range you wanted. The random command is written as - Random wordvariable or Random W0 for example This would generate a random number between 0 and So how do you convert that into a random number that you want such as 1-6 or 10-5? The following random idea is from a Picaxe forum member called Hippy. The following formula is used - W1 = W0 // (NumMax - NumMin +1) + NumMin The formula in brackets is not put in your program, but worked out beforehand. As an example, if you wanted a number between 10 and 5 - W1 = W0 // ( ) + 10 W1 = W0 // (16) +10 W1 = W0 // Any random number you want is then able to be worked out. The following program can be run in the simulator to see if the random numbers generated are correct. new: random w0 w1 = w0 // pause 00 goto new Don t forget to change the variable type from byte to word to see your random numbers or else the numbers printed will not be correct.

14 The Servo command is quite simple to use - Servo 1,150 Move servo on output 1 to position 150. But during the last year, the servo command has been updated to make it more reliable. You can still use the old command, but if your servo is jittery it might be an idea to try the new code to se if it fixes the problem. All you need to do is at the start of your program issue the servo command to turn your servo on, and then in the rest of your program use the servopos command instead. If you do not have the servo command at the start of you program, the servo will not move later on for the servopos commands. Below is an example of the old code - new: wait servo 1,75 wait servo 1, 5 goto new Now the same program with the now servopos code- To pause for a certain amount of time, to blink an led of or randomly move a holoprojector, there are two different commands to accomplish this, the Wait command and the Pause command. The wait command works in seconds so wait 1 is one second, and wait 10 is ten seconds. 75 servo 1,75 new: wait servopos 1,75 wait servopos 1, 5 goto new The pause command works in thousandths of a second, so pause 500 is half a second and pause 1000 is one second. Use whatever is appropriate for your application. The only time this changes is when the setfreq m8 command is used to double the speed of the Picaxe system. As it is doubling the speed of the Picaxe, the wait and pause commands are halved. So wait 1 is now half a second, and pause 500 is now one quarter of a second. Please keep this in mind when programming timing based applications when using the setfreq command.