Spin questions
turbosupra
Posts: 1,088
As I'm trying to teach myself the syntax of spin, I figured I'd start with a basic project. If there is a basic example of different programs and code examples that I can look at, all in one pdf, please link me to it.
I'd like to get the framework of the necessities of a spin project (the very basic code) so I can see a template of what is needed for every project.
It appears that you need
CON
_clkmode
_xinfreq
to define your crystal and timing and any other constants
Then you need
VAR
to define any variables needed and reserve a memory address for them, depending on the variable type
and then you need
PUB Main (or multiple pubs)
to define public functions
With all of that being said, I want to have spin count 3 pulses within a third or half second and if it sees that, output a high to turn on a transistor for 1000 milliseconds, so here goes
Post Edited (turbosupra) : 6/12/2010 12:09:53 AM GMT
I'd like to get the framework of the necessities of a spin project (the very basic code) so I can see a template of what is needed for every project.
It appears that you need
CON
_clkmode
_xinfreq
to define your crystal and timing and any other constants
Then you need
VAR
to define any variables needed and reserve a memory address for them, depending on the variable type
and then you need
PUB Main (or multiple pubs)
to define public functions
With all of that being said, I want to have spin count 3 pulses within a third or half second and if it sees that, output a high to turn on a transistor for 1000 milliseconds, so here goes
CON
_CLKMODE = XTAL1 + PLL16X
_XINFREQ = 5_000_000
quartersec_wait = 250 ' counts every 1/4 second
thirdsec_wait = 333 ' counts every 1/3 second
halfsec_wait = 500 ' counts every 1/2 second
twothirdsec_wait = 667 ' counts every 2/3 second
threequartersec_wait = 750 ' counts every 3/4 second
fullsec_wait = 1000 ' counts every 1 second
OBJ
'Reserved
PUB Main
dira[noparse][[/noparse]7] := 0 ' sets the direction of pin 7 to an input
ina[noparse][[/noparse]7] := 1 ' sets pin 7 to look for a greater than 1.65vDC signal
dira[noparse][[/noparse]8] := 1 ' sets the direction of pin 8 to an output (may be redundant)
outa[noparse][[/noparse]8] := 1 ' sets pin 8 to a high output to turn on a transistor
repeat
if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC
WaitCnt(ClkFreq / 1000 * thirdsec_wait + cnt) ' wait a 1/3 of a second and poll input pin 7 again
if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC a second time
WaitCnt(ClkFreq / 1000 * thirdsec_wait + cnt) ' wait a 1/3 of a second and poll input pin 7 again
if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC a third time
outa[noparse][[/noparse]8] == 1 ' set output pin 8 to high
WaitCnt(ClkFreq / 1000 * fulsec_wait + cnt) ' leave pin 8 set to high for a full second
outa[noparse][[/noparse]8] == 0 ' reset output pin 8 to low
Post Edited (turbosupra) : 6/12/2010 12:09:53 AM GMT
Comments
And look at :=, too.
Post Edited (ElectricAye) : 6/11/2010 10:53:26 PM GMT
As I understand it
= is for equal in the CON code block
== is for is equal to for a variable
:= is for equals when assigning a variable
I tried to correct my code, did I do it correctly?
This will allow you to put in your constants as you have them.
ClkFreq / 80000000 will always equate to 1 if you are running at 80MHz (which you are) or above, and 0 if less than 80MHz.
Clkfreq always contains your current clock speed (80,000,000).
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April, 2008: when I discovered the answers to all my micro-computational-botherations!
Some of my objects:
MCP3X0X ADC Driver - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm - Fast communication between two propellers (1.37MB/s @100MHz)!
Thank you for that, do you mind explaining why you use your method? Also did everything else look ok?
This sets what the propeller understands as the current frequency: _XINFREQ (your XTAL frequency) multiplied by the PLL16X mode. So 5MHz * 16 == 80,000,000Hz. This value is now what clkfreq contains.
So if you do the math (from my waitcnt) clkfreq / 1000. This derives 80,000. Which happens to be exactly how many cycles the internal clock in the propeller must progress before 1 millisecond passes. So if you then multiply this value by the number of milliseconds you want to wait you have the total number of clock cycles the propeller needs to pause for. For example a quarter second is 250ms. So 250 * 80,000 == 20000000.
Then you must add cnt which contains the current clock position. It is basically like saying "x milliseconds from now, stop the pause" if you leave out the cnt, it is unclear how long to pause for, it would depend on where the clock currently is. For now, all you need to know is waitcnt always must have + cnt at the end of the parameter (until you get into some advanced stuff).
As for other things, OUTA's and DIRA's are just like variables (the are actually registers). So you store and access them the same as variables. So assigning 1 to OUTA[noparse][[/noparse]8] is done like this:
You didn't do that correctly in your REPEAT loop.
INA is a read-only register, so you cannot assign it (as you did). I will post below what I think you want (though I am unable to test it, you can do that for yourself).
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April, 2008: when I discovered the answers to all my micro-computational-botherations!
Some of my objects:
MCP3X0X ADC Driver - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm - Fast communication between two propellers (1.37MB/s @100MHz)!
CON _CLKMODE = XTAL1 + PLL16X _XINFREQ = 5_000_000 quartersec_wait = 250 ' counts every 1/4 second thirdsec_wait = 333 ' counts every 1/3 second halfsec_wait = 500 ' counts every 1/2 second twothirdsec_wait = 667 ' counts every 2/3 second threequartersec_wait = 750 ' counts every 3/4 second fullsec_wait = 1000 ' counts every 1 second PUB Main ''no need to set pin 7. by default it is set as an input 'dira[noparse][[/noparse]7] := 0 ' sets the direction of pin 7 to an input 'ina[noparse][[/noparse]7] := 1 ' sets pin 7 to look for a greater than 1.65vDC signal dira[noparse][[/noparse]8] := 1 ' sets the direction of pin 8 to an output (may be redundant) '' this is not redundant, they are default as input outa[noparse][[/noparse]8] := 1 ' sets pin 8 to a high output to turn on a transistor repeat if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC WaitCnt(ClkFreq / 1000 * thirdsec_wait + cnt) ' wait a 1/3 of a second and poll input pin 7 again if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC a second time WaitCnt(ClkFreq / 1000 * thirdsec_wait + cnt) ' wait a 1/3 of a second and poll input pin 7 again if ina[noparse][[/noparse]7] == 1 ' if pin 7's input is higher than 1.65vDC a third time outa[noparse][[/noparse]8] := 1 ' set output pin 8 to high WaitCnt(ClkFreq / 1000 * fulsec_wait + cnt) ' leave pin 8 set to high for a full second outa[noparse][[/noparse]8] := 0 ' reset output pin 8 to lowYou set OUTA[noparse][[/noparse]8] high before the loop, then you set it high again after pin 7 is high three times. Do you want pin 8 to be low to start with, then set it high to turn on whatever for a second? Or is this now doing what you expect?
Just as a side note, I usually use the tildes to set my pins. So I would do OUTA[noparse][[/noparse]8]~~ or OUTA[noparse][[/noparse]8]~. I find it more readable than numbers, but I know for normal numbers the tilde is slightly slower for setting variables, I don't know about pins though. I am not sure what the general consensus is on how to set pin states. Ultimately, as long as it works, and you are the only one reading the code, it doesn't matter.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
April, 2008: when I discovered the answers to all my micro-computational-botherations!
Some of my objects:
MCP3X0X ADC Driver - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm - Fast communication between two propellers (1.37MB/s @100MHz)!
Thanks!
I'm going to try and explain better what I'd like it to do
When I wrote
I thought I was telling the prop that when I called this pin in the future code, I'd like it to output a 3.3v signal
When I wrote
I thought I was telling the prop to put out 3.3vDC at that moment
And when I wrote
I thought I was telling the prop to put out a DC ground value now in essence turning off the 3.3vDC
I have a feeling I did the actual 3.3v voltage out code incorrectly. To write in psuedocode, I'd like for pin 7 to count the number of highs it sees and if it sees 3 within 1/3 of a second of each other back to back to back, I'd like for pin 8 to output 3.3v for 1000milliseconds to an NPN transistor base which will control triggering a relay.
When you want to assign a value to a variable, you should use :=
When you want to determine if one value is the same as another (for integers only), then use ==
You are still getting these confused. EDIT: Okay, looks like you fixed those in the previous post.
Have you worked your way through the Propeller Educational Kit labs yet? These labs will help you understand these basic concepts.
See this page:
http://forums.parallax.com/showthread.php?p=617192
Post Edited (ElectricAye) : 6/12/2010 3:37:14 AM GMT
I'm going through the prop PM1.1 and the spin code example ebooks now, and that is where these questions stem from.
Thank you for your help
this kind of signal-checking is not expert-niveau but it is already advanced niveau. I will explain why:
The suggested solution will only work if the pulses arrive VERY exactly.
The WaitCnt-commands STOPS the cog completely. If the pulses arrive faster then a pulse might be already finished before the polling for the pulse
is working again.
Let's say the pulses should arrive within 300 millisecs.
If you have a pulsetrain of five pulses where the time between the times are as this
P1--305-msecs---P2----299-msecs---P3----297-msecs---P4----285-msecs---P5----310-msecs---
The logic will be still in the middle of the checking and will NOT detect the correct pulse-train of pulses no P2-P3-P4
If the inputpin stays high for a long time this will be detected wrong as three pulses
If I understand right the time between the three pulses CAN to be much shorter than the timeout
In the attachment you will find a spin-file that does it that way by measuring the time from low-high to the next low-high-transistion
best regards
Stefan
I'm going to look at your code and try to figure it out [noparse]:D[/noparse]
Thank you very much!
I understand about 75% of your code, but when there are lines such as this
What does that mean when one variable has another variable as an array? Can you use example numerical values?
simple example of using an array
now the following would do the same
result after the last operations
anotherArray[noparse][[/noparse] 0 ] contains 110
anotherArray[noparse][[/noparse] 1 ] contains 220
anotherArray[noparse][[/noparse] 2 ] contains 330
whenever you use a variable or an expression the variable or expression
gets evaluated and the evaluated value is used
so MyVar will contain
'showing the evaluation step by step
'result
MyVar contains value 1009
best regards
Stefan
Post Edited (StefanL38) : 6/13/2010 4:29:57 PM GMT