|
DAVE, you fixed it!!
COUNT is the solution. This is BIG. My target RC car is the HPI Sprint. In comes in a Ready To Run package for around $200 including a two channel radio system. I have been using channel three to make the TOGGLE between R/C and PIC control. This is an expensive variation. Now a plain vanilla RTR Sprint should do the job! THANK YOU.
Ken
|
COOOOOL!!!!!
I can not wait to see new videos.
Dave
Always wear safety glasses while programming.
|
What is the best way to learn 8 bit Assembly?
I have "16 BIT LANGUAGE TOOLS GETTING STARTED" DS70094E. My 16F887 is an 8 bit machine. What is the best way for me to learn ASM for my PIC? I have not been able to get MPLAB IDE v8.33 to work. Is that because I am dealing with an 8 bit PIC?
Ken
|
MPLAB should work with any PIC. What is it not doing?
Assembly???
Hang out here
http://www.piclist.com/techref/piclist/index.htm
Dave
Always wear safety glasses while programming.
|
It did not like the ASM code
I gave MPLAB IDE some .asm code created by MicroCode Studio. It claimed too many errors. That was many months ago. I'll try again.
Ken
|
In the Project drop down from the tool bar - select language toolsuit, select:
Microchip MPASM Toolsuite
That should then compile ASM generated by PBP.
Dave
Always wear safety glasses while programming.
|
Yes, but....
That's the way I have been compiling.
When I cut and paste a .asm that was created by the compiler into the MPLAB IDE application window it refused to assemble. I think there are some idiosyncrasies that I need to learn.
Ken
|
Maybe the wrong PIC was selected?
Toolbar-Configure-Select device
Dave
Always wear safety glasses while programming.
|
PICKIT 2 Programmer Application??
I've built my first solderless proto using a 40 pin 16F887.
As far as I can tell I have duplicated the actions that up until now have worked. The PICKIT 2 Programmer "Check communication" says "PICKIT 2 found and connected" "PIC device found"
However when I click the Write button using the 40 pin PIC, the PICKIT 2 Programmer application says "Programming failed at program memory address LOCATION 0x000002"
Any ideas?
Ken
|
Some possible causes. Maybe...
Are both VDDs and VSSs connected?
Do you have capacitors across both VDDS and VSSs?
Dave
Always wear safety glasses while programming.
|
It's working
No sure what was wrong. Maybe a solderless connection was not tight.
Got a couple warning windows about voltage must be 4.5v.
Strange since the power is coming from my PC via the USB port. Then that went away. Got a couple of red "Code Protect" statements. Had to restart the application to get ride of them.
Twice in a row it loaded my .hex file successfully. Good!! Now to adding sonars, SN7404 and the DPDT relay.
Thanks for the support. It really helps!
Ken
|
Hpwm??
How do I learn exactly what the 16F887 does when given a HPWM PBP command? Seems to me the car's electronic speed control (and hence the car) reacts slower to PIC PWM signals than to radio control PWM commands.
I was wondering if throwing a LOW at the PWM output port might slow the car down quicker than just changing HPWM commands from 'forward' to 'reverse'.
Is this a potentially worthwhile path of inquiry? Something is slower than it should be and it is not the sensor trigger rate.
Ken
|
I wonder if something like this could be made to work for you?Originally Posted by Kenjones1935
I want to use the interrupt system to make my Pulse Width Modulated pulses output at 50hz. I am hoping that will give me finer control of the wheel speed and maybe a quicker steering response.
I understand that I need to preset TMR1 with a number so that it rolls over every 20 ms. thereby triggering the interrupt. How do I figure out what that preset number should be and how do I set it using PBP?
Ken
http://www.picbasic.co.uk/forum/showthread.php?t=7393
or
http://www.picbasic.co.uk/forum/cont...gle-Modulation)
Dave
Always wear safety glasses while programming.
|
Cool chip for R/C PWM: 18F2431 series
After reading about some of Bruce's cool projects with the 18F2431 series chips, I have been playing around with them for a little while. One thing that caught my eye is that they can do Power Control PWM as low as 19 hertz (while running at 40 mhz). Something you have to bring other chips OSC down to 0.5 mhz to do. This, and a few more of it's features, make it pretty nifty for creating PWM servo output. I mocked up a quick test, and have been able to do about 10bit PWM 1 to 2ms pulses at the proper 50 hertz spacing on 3 pins with the 18F2431. The larger chips of this series can do 4 pin PCPWM. I will post a little code once I get it cleaned up a bit.
Last edited by ScaleRobotics; - 26th July 2010 at 18:15.
|
The new Electronic Speed Control is messing with my head
I received a brand new HPI Racing Sprint car. This is the same model which I have been using. It is just the most recent version.
I am having a problem with the new Electronic Speed Control a SC-15. It has some kind of mind of its own. My old code which told my old car where to go is not working with this new ESC.
Do any of you have the contacts to get me the specs on this "SC-15 ESC WITH REVERSE SPORT CONTROL".
Does is have a PIC? Is it programmable? What are its design algorithms?
Ken
|
Servo pwm passthrough using PCPWM
The 18F2431 makes it slightly easier to perform servo PWM because it's PCPWM module can go down to 19 htz while maintaining fast OSC rates, unlike other PIC chips HPWM. Here is an example of using the PCPWM to output 3 servo signals. This specific example senses the pulses (up to 5 channels) by using the CCP1 capture pin. To get 5 channels into one pin for PW capture, channels 1, 3 and 5 are input using small signal diodes. Then, since this drops the signal down to under 3 volts, I used two 2n3904 transistors. One to boost up the voltage, and the other one to invert the signal back to normal. (It was all I had lying around). Somehow, you will need to boost your signal after the diodes for the CCP1 capture to sense the incoming pulses.
Note: Because the PCPWM was used, this will not work on any chip outside of the 18F2431 family.
To see a similar project, but using SPWM, look here: http://www.picbasic.co.uk/forum/showthread.php?t=12657Code:;This only works on a 18F2431 family device with Power Control PWM (PCPWM) ;By Scale Robotics Inc. ; The input signal should look something like this:- ; ; |<------------------ 1 frame (~20mS) -------------->| ; |<1~2mS> ; ______ ______ ______ ______ ; _______| |______| |______| |________________| |____ ; gap ch1 ch2 ch3 ch4 ch5 sync gap ch1 etc define OSC 40 asm __CONFIG _CONFIG1H, _OSC_HSPLL_1H __CONFIG _CONFIG2H, _WDTEN_OFF_2H & _WDPS_512_2H __CONFIG _CONFIG4L, _LVP_OFF_4L endasm clear ADCON0 = %00000000 ADCON1 = %00000000 portb=0 trisb = %11000000 trisc = %00000110 trisa = %00000000 DTCON = %00000101 'dead time for complimentary ouputs PTCON0 = %00001101 '1:1 postscale, Fosc/4 1:64 prescale, Sincle Shot mode PTPERL = 255 ' PTPERH = 251 PWMCON0 =%01010000 'PWM[5:0] ouputs enabled PWMCON1 = 1 'updates enabled, overrides sync w/timebase PTCON1 = %10000000 'PWM timebase is on, counts up FLTCONFIG = %00000010 'disable fault A, cycle by cycle mode CCP1CON = %00000101 'Capture mode; every rising edge duty1 var word 'width of outgoing pulse1 duty2 var word 'duty values 625 to 1250 = 1 to 2 ms pulse (Center at 625) duty3 var word risetime1 var word 'Rise Time for incoming pulse1 risetime2 var word risetime3 var word falltime1 var word 'falltime for incoming pulse1 falltime2 var word falltime3 var word pulsewidth1 var word 'pulse width for incoming pulse1 pulsewidth2 var word pulsewidth3 var word pulsewidth4 var word pulsewidth5 var word pulseNumber var byte pulseNumber = 1 'tells which pulse we are reading CCP1CON.0 = 1 timerone var word timerone = 60315 ; INCLUDE "DT_INTS-18.bas" ; Base Interrupt System ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR5_INT, _PulseOut, ASM, yes INT_Handler CCP1_INT, _PulseMeasure, ASM, yes INT_Handler TMR0_INT, _TimeOut, ASM, yes endm INT_CREATE ; Creates the interrupt processor ENDASM T1CON = %00110001 ;Timer1 used by CCP1 capture T5CON = $01 ;used as pulseout timer T0CON = %11000111 ; Prescaler = 8, TMR1ON @ INT_ENABLE TMR5_INT ; Enable Timer 1 Interrupts @ INT_ENABLE CCP1_INT ; Enable Capture Compare for pulse width measurement @ INT_ENABLE TMR0_INT ; deadtime (sync gap) indicator for lull between pulses Main: pause 10 'do something to these values if you want to filter, center, etc 'Below we are just passing values through duty1 = pulsewidth1 >>1 'send channel 1 out PCPWM on PortB.1 duty2 = pulsewidth3 >>1 'send channel 3 out PCPWM on PortB.3 duty3 = pulsewidth5 >>1 'send channel 5 out PCPWM on PortB.4 GOTO Main '---[TMR5_INT - interrupt handler]------------------------------------------ PulseOut: 'set up pulse width values for pulseout and reset single shot bit TMR5L = timerone.byte0 TMR5H = timerone.byte1 PDC0L = duty1.lowbyte PDC0H = duty1.highbyte PDC1L = duty2.lowbyte PDC1H = duty2.highbyte PDC2L = duty3.lowbyte PDC2H = duty3.highbyte PTCON1.7=1 'resets single shot PTEN bit @ INT_RETURN '---[CCP1_INT - interrupt handler]------------------------------------------ PulseMeasure: if CCP1CON.0 = 1 then ; Check CCP1M0 for rising edge watch select case pulseNumber case 1 TMR0L = 0 'reset timeout timer0 TMR0H = 0 risetime1.lowbyte = CCPR1L risetime1.highbyte = CCPR1H case 2 TMR0L = 0 'reset timeout timer0 TMR0H = 0 risetime2.lowbyte = CCPR1L risetime2.highbyte = CCPR1H case 3 TMR0L = 0 'reset timeout timer0 TMR0H = 0 risetime3.lowbyte = CCPR1L risetime3.highbyte = CCPR1H End select @ BCF CCP1CON, CCP1M0 ; Now capture the trailing edge Else 'check for falling edge time @ BSF CCP1CON, CCP1M0 ; Re-set for trailing edge capture select case pulsenumber case 1 falltime1.lowbyte = CCPR1L falltime1.highbyte = CCPR1H pulsewidth1 = falltime1 - risetime1 case 2 falltime2.lowbyte = CCPR1L falltime2.highbyte = CCPR1H pulsewidth2 = risetime2 - falltime1 pulsewidth3 = falltime2 - risetime2 case 3 falltime3.lowbyte = CCPR1L falltime3.highbyte = CCPR1H pulsewidth4 = risetime3 - falltime2 pulsewidth5 = falltime3 - risetime3 end select pulsenumber = pulsenumber + 1 'get ready for next channel endif @ INT_RETURN '---[TMR0_INT - interrupt handler]------------------------------------------ TimeOut: pulsenumber = 1 'if pause between pulse in exceeds about 7 ms, get ready 'to receive pulse 1 (senses dead time between pulse bursts) @ INT_RETURN
Last edited by ScaleRobotics; - 28th July 2010 at 19:08.
|
Thank you, Dave
Yes, the 18F2431 looks like a winner for my PWM construction. It is included in my PICkit2 programmer.
It comes in a 40 pin package. It would easily replace my 40 pin 16F887 on the solderless protoboard. To use it effectively I need to master ASM coding. I have not succeeded in cracking that nut.
Here is my latest stumbling block. I have an arrangement with some folks who are willing to contribute brand new HPI Racing Sprint cars to my project. I received my first new car last week. HPI has drastically changed the Electronic Speed Control. This is the package that translates incoming PWM signals (from the radio receiver or from my PIC) into outgoing DC current for the motor that drives the wheels. I am not doing well with the HPI WEB site getting technical information about this SC-15 WITH REVERSE SPORT CONTROL.
Ken
|
Hey Ken,
Congratulations on getting the donation! It is a great idea you have, and I am glad you have stuck with it. As for your newest stumbling block, what code are you currently using? You might be running into the same problem of not having a standard R/C output pulse going to the controller. And MIBAM will not work, because it is meant for lighting, and will confuse your speed controller even more.
All analog servos (not the newer digital ones) use a standard protocol. A pulse width from about 0.9mS to 2.1mS or so, pulsed every 20 mS. Since this controller does not say digital on it, I would bet that it is analog, and works the same as all the servos in my house. Since it has reverse, as well as forward, I would bet that somewhere in between .9mS and 1.1 mS is neutral. Less is probably reverse, and more is forward.
I don't think you need a manual for it. Just start feeding it some PWM that matches that protocol, and you will be good.
Assembly is a tough nut to crack. It's just one of those things, the more you use it, the more you learn. But one of the things I learned this week from the forum, was that I could have an instant ASM interrupt without using any ASM. No, I didn't know that when I wrote some similar code for the 12f683. So in my example above, I only used two lines of assembly code. a BSF and a BCF. (Bit set and bit clear). So you can have almost no nuts with this code, or you can change them to PBP code if they drive you ... um ..... nuts.
I think you already know this, but I just found the gif file, and I like it, so I'll post it here. - Walter
Last edited by ScaleRobotics; - 29th July 2010 at 16:04.
|
I was always led to believe it was typically 1ms to 2ms with a 20ms frame rate this gave 1.5ms pw for centre stick, at least that's what I've always based my SSC type projects on.
|
I think this ESC is different
I agree with both of you on the size, shape and frequency of standard PWM signals. I have been running my car (an older version of this same HPI Sprint) successfully for the last couple of months. With the exception of frequency my HPWM pulses agree with your specs. I found the correct HPWM commands by trial and error.
This new Transmitter, Receiver, ESC combo is different. Leaving out my PIC for the moment if I on the radio transmitter I give full forward (trigger full back) and suddenly go to full reverse (trigger full forward) the car goes from full forward to stop (neutral in the PWM sense) and stays there until I bring the trigger to neutral for at least two seconds. Then giving it full back will work fine.
Somewhere in the system is protection against slamming the DC motor with reversed polarities. That is good, but when I tried to emulate that system in my code it did not work.
Thank you sooo much for your support and interest. Oh, yes, the electronic speed control wheel driving system is not a classic servo. Steering is. Wheels used to be - in the day - but no longer.
Ken
|
Edit: oops, yes I meant to say 2.1 as the highpoint, not 1.1. Thanks Malc!
Hey Malc,
Yeah, me too! As a basic rule it works. But then I built my first passthrough device, I built it for that range and it got discombobulated when the signals from my transmitter exceeded the 2 mS. My transmitter has endpoint adjustments, so it allows you to go beyond the 1 to 2 mS. Some transmitters will only give 1.1 to 1.9ms.
Check out the HiTech web site regarding the signals:
You are probably right, I just was not sure if a forward and reverse speed control would be centered at 1.5 mS. My planes don't have reverse.
Last edited by ScaleRobotics; - 29th July 2010 at 16:04.
|
Well, that's a completely different problem than what I thought you had. Why not talk to your friends at the R/C store and find out if they know of any controllers that let you go reverse from full forward. If they do, sell the controllers you have on Ebay, and buy the ones you want with the money?
You might also be able to hack the speed controller if it is for a brushed motor. But you run the risk of breaking a $55 speed control. You could also build your own controller for a brushed motor, but easier to find one off the shelf that will do what you want, if it exists.
Last edited by ScaleRobotics; - 29th July 2010 at 18:20.
|
Yea, but...
I have been successful in attracting some support for my project. Check out
http://www.ten80education.com
They use HPI Sprint cars.
If I can design a 'simple' enough PIC kit to add to the standard HPI product, the schools might get a pretty good deal. My new car was a support gift cost me nothing.
Ken
|
Electronic braking system. - You might be able to go into the programming mode and disable this function.
|
Uhmm maybe that's not an option. I can't see anything on programming the end points on this controller
|
Just got back into town...
OKAY,
I have discovered through the use of my oscilloscope that PAUSE stops the HPWM output pulses. In order to emulate the radio system I want to try giving the ESC two seconds worth of neutral PWM between switches back and forth between forward and reverse. This is a race car. It will not be going backwards very often, but it is necessary sometimes. Looks like I need to figure out how to set a two second interrupt. Hmmmm. NUTS!
Ken
|
Hey Ken, welcome back to town.
Do you mind posting some of your code for us to figure out what is going on? The HPWM command, or using the CCP hardware PWM with your own commands should both work independently of your code. I have a 2 second pause that is repeated, but HPWM keeps pumping out pulses the entire time. But if I repeatedly call HPWM and set it using PBP, it can give me some screwy results. Probably better setting the registers directly, like Bruce shows in this example: http://www.picbasic.co.uk/forum/show...1478#post61478
What PIC hardware are you using?
Thanks,
Walter
http://www.scalerobotics.com
|
I'm using a 16F887
Here is the first couple commands of my code. I deliberately start HPWM then PAUSE for four seconds. My oscilloscope shows a flat line for four seconds then springs in PWM action.
I just looked at it again. I am no longer as certain as I was. Once I get into my code it seems to behave as I expect. I'll get back to you all tomorrow.
Thanks, Ken
|
Here's some code.
The outputs of PORTC.1 and PORTC.2 are high all the time.
Why? In other code snippets PAUSE seems to allow action to continue. I hope you guys see that I am being stupid.
Code:' PORTC.0 'High is R/C. Low is PIC control TRISC = %11110000 main: low portc.0 gosub straightforward pause 4000 goto main end StraightForward: pwm 1,120,50 pwm 2,120,50 return
|
I see it already
As soon as I typed "submit" I saw that I had left out the H in HPWM. Thank you sooo much!
Ken
|
Glad to hear it. The bad news is that HPWM doesn't go down as low as 50 hertz, unless you use a really low osc speed. You have to go down to 0.5 mhz to get there. And, unfortunately you have to tell pbp that it is running at 4mhz. This will make a pause 2000 16 seconds. It can be compensated for, but a bit of a pain. And it limits you to 32 steps of speed. I think I talked about this back on post 199. Maybe that's why you tried to go back to PWM. But as you saw, PWM is effected by blocking commands, like pause.
http://www.picbasic.co.uk/forum/show...5908#post85908
I don't have a 16F887, but I just ordered a sample, so I can help test some options for you.
Walter
http://www.scalerobotics.com
|
I also miss wired!!!
First I used my 44 pin PIC (with no PICKIT 2 board) on a toy level car. Toy level means bang-bang control. It worked.
Now I am running a model level car with PWM control. I miss wired CCP1 and CCP2. Steering was going to the wheels. Driving was going to the steering servo.
I thought I had double checked this. Clearly my double checker was flawed. I shall rewire and report back.
Thank you for your patience.
|
wiring correctly eases understanding BASIC
Yup,
Now when it sees something in front it stops then goes backwards.And when nothing is in front it goes forward for all its worth. Such a difference getting the steering servo and the wheel electronic speed control signals actually going to the servo and the ESC.
Now to calibrate HPWM for this fancy ESC. It seems very similar, but not exactly like the old not-so-fancy ESC. There are still funny rules around switching from forward to reverse and visa verso.
Ken
|
It's working
Another 'minor' problem. The new HPI Sprint has the steering servo mechanically opposite my older car. With this car steering right is smaller PWM pulses. Steering left is larger.
Soooo Things are working as they used to. My problem now will be getting a reaction time that is reasonable given the speed of the car. I have not taken it to a gym or outside. When I hold a big cardboard in front of the car it does turn. Soon enough? We'll see... I can slow down the wheels, but this is supposed to be a race car.
Ken
Ken
|
New car - its first outing
It worked better before I went in and to get my video camera. However, you can get the idea from this clip. There are still some mysterieswith the HPI's new Electronic Speed Control SC-15.
Little by little....
Ken
|
I think the car is been autonomous enough and wants to escape now! Was very funny how it got away under the white car!
Keep up the good work Ken.
Ioannis
|
I ran for two minutes autonomously
This afternoon I taped a two minute video in which my new HPI Sprint car ran autonomously around and around the inside of our garage. The radio transmitter was turned OFF during the whole episode. At no time in this piece did I interrupt the PIC control with the radio control. I was operating the video camera.
Go to:
http://www.youtube.com/watch?v=jI5JEeT_FDE
What do you think?
Ken
|
Very nice!!!
Almost looks like it was "thinking" after it hit something.
Dave
Always wear safety glasses while programming.
|
What version of code is in my PIC
If I have recorded the checksums how can I know which version of code is on my PIC?
The PIC KIT 2 programmer has a READ button. Does that read the contents of my program memory and display for me to see its checksum?
I have not figured out on-line debugging. Actually I have not figured out a great deal of stuff in this system.
Ken
|
Yes, it will display the checksum after it reads the code from the PIC chip.
You could use the verify button. It will compare the file loaded onto the pickit from your computer to what it reads on the PIC chip. It will notify you of any differences.
http://www.scalerobotics.com
Members who have read this thread : 4You do not have permission to view the list of names.
Posting Permissions
Bookmarks