RoboSavvy Forum

my posts useful? psh..

2006-04-26T18:22:28+01:00

Ok, so i guess i lost my battery...
My RN1 passed out on me while holding a steady light. I'll try upping the value a little, but it seems very inconsistent.. Does adding the resistors make it more reliable or is it basically the same as changing the code, but in hardware form?

Statistics: Posted by Octovir — Wed Apr 26, 2006 6:22 pm

New low voltage code ? please help

2006-04-25T07:12:15+01:00

for what its worth, i hooked up a digital meter to my batt as i played with the voltage code. The meter showed 6.8v at no load. I figure my battery was less than half charged.. anyway, hooking it up and powering on, voltage dropped by about .2v. After a few minutes of multiple compling and uploadings and loading the servos a bit, it seemed a value of 85, triggered right around 6.2v, so i powered off and began this message. But for consistency's sake i decided to double check and out the door went consistency!.. i started moving the values up to try and match the 6.6v i was getting and 86 seemed to trigger the led at about 6.35 volts, but other times i could bring it down below 5v and still a solid LED..

conclusion:
im willing to bet my battery that "Value/13.5 = Voltage" is a suitable equation for determining a cutoff point (im picking 77 because i feel lucky..)

besides that its my first reply so i wanted to say something useful..

Statistics: Posted by Octovir — Tue Apr 25, 2006 7:12 am

New low voltage code ? please help

2006-03-22T19:47:51+01:00

I agree with Rubik and you need to add the circuitry. R1 & R2 do not refer to existing resistors on the 3024 board. If you check the input pin for AD(6) you will see that there is no voltage on it. Just comment out the voltage check routine call until you add the required circuitry but be aware that you can over-discharge the batteries.
This is a glaring problem with the setup. There needs to be an under-voltage cutoff circuit to prevent that from happening. I have added one to my Nova. It is connected to the output enable line of my DC\DC converter.
I use one of these: http://ww1.microchip.com/downloads/en/a ... 00779a.pdf
Maybe tying the output of the TC54 to the processor reset pin would do the trick? Would probably be pretty erratic when at the setpoint though.

I think at a minimum you should add the resistors and change the code so that the robot sits down and powers off the servos when an under voltage occurs.

Statistics: Posted by subpilot — Wed Mar 22, 2006 7:47 pm

New low voltage code ? please help

2006-03-22T16:24:50+01:00

I think you need to put a resistor cicrcuit between +votlage and ground

' {Value(A) / 256} * 5.0V * {(R1 + R2) / R2} = BATT-Voltage

'{sample schema}
' BATT --[R1]-+
' |
' +--- AD(6)
' |
' GND --[R2]-+ ex. R1=10k,R2=10k

Statistics: Posted by RubikCube — Wed Mar 22, 2006 4:24 pm

New low voltage code ? please help

2006-03-22T02:19:21+01:00

You can find mentions of this same problem in some of the previously listed topics. Topics like 'Blinking headlight oops' and 'Working with my Robonova'. They go through what some of us have already gone through. For those of you who may be newer to the forum, it is suggested that you read through past postings and add to the ones that already exist (that relate to your problem) rather than starting a new topic. This will make referencing questions and their answers easier as more and more people join. Anytime you add to one of the existing topics, it moves to the top so we all know it's been changed or added to, and can then respond.

Statistics: Posted by bauermech — Wed Mar 22, 2006 2:19 am

New low voltage code ? please help

2006-03-21T23:35:34+01:00

THAT HAS STOPPED HIM FLASHING BUT NOT SURE ,DONT WANT TO PULL THE BATTERY DOWN TO FAR ? HAVE YOU ANY EXPERIENCE WITH ADDING A GYRO.

Statistics: Posted by rep001 — Tue Mar 21, 2006 11:35 pm

New low voltage code ? please help

2006-03-21T23:30:05+01:00

HOW DO YOU COME TO 58 ?

Statistics: Posted by rep001 — Tue Mar 21, 2006 11:30 pm

New low voltage code ? please help

2006-03-21T23:28:15+01:00

I think the formula is wrong.
Try 58 instead of 128.

Statistics: Posted by ucrobots — Tue Mar 21, 2006 11:28 pm

New low voltage code ? please help

2006-03-21T21:38:13+01:00

Chaps what am i doing wrong.My RB has a constant flashing head ?
I thought i may need to lower the voltag threshold and have tried to do so,but he still flashes from a fresh charge with 7.6v at least in the pack.here is a copy of the code i changed and really need someone to help or tell me i am a muppet .........
robot_voltage:' [ 10 x Value / 256 = Voltage]
DIM v AS BYTE

A = AD(6)

IF A < 128 THEN ' 5.0v

FOR v = 0 TO 2
OUT 52,1
DELAY 200
OUT 52,0
DELAY 200
NEXT v

RETURN

HELP !!

Statistics: Posted by rep001 — Tue Mar 21, 2006 9:38 pm