Battery monitoring.

[HertzHog]

Battery monitoring. (There is a happy ending!)

I'm new to this forum and I have read the manuals but failed to find the answer to many simple questions. I think these chips are really neat and the forum impressive.
Question 1 what is the likely consequence of enabling or disabling brown out detection with DISABLEBOD, what does it actually do? apart from a reduction in power use which seems not quantifiable. I think the Code examples are pretty useless on the Basic Tutorial.

"main:	disablebod	; disable brown out
	sleep 10	; sleep for 23 seconds (2.3x10)
	enablebod	; enable brown out
	goto main	; loop back to start"

Personally, I think all the snippets really should do something useful, I am afraid that many do not.

I became interested in Picaxe when I wanted to develop a very accurate thermometer for an incubator. I found with an AXE049, I could make a great monitor for an incubator with just the addition of a resistor and a DS18B20 chip. And of course, a program. It measures temp and logs and displays maximum and minimum and ~mode temperature with arbitrary High and Low thresholds. All displayed to precision on just 1 7 segment chip. The beauty of a microprocessor is that it can be tasked to only record max and min temperatures AFTER it has temperature stabilised in its environment. So, I can use it to record the coldest temperature in an incubator even though it starts by being reset in a cool room. Or warmest temperature in a fridge etc.
However, I found it misread the temperature at a point the battery ran down to the point the Picaxe worked BUT the temp chip clearly did not. So...

Question 2 Can you explain if / how the chip can sense to alarm or shut down a project 'cleanly' i.e. under control, when the project 4.5v battery voltage falls to say 3v. I assume you need to use calibadc or similar?
I have read the manuals but...
I found the code snippet

"main:	calibadc10 w1	; read the adc reading
	debug		; display current value
	pause 500	; wait a while
	goto main	; loop back to start"

unhelpful.

please excuse any perceived negativity. If I did not rate this forum I would not post in it. HertzHog

 

[manuka]

HertzHog: Welcome, but perhaps tell us more about your skills,background,age (?) & resources. The Forum's brains trust may otherwise make invalid assumptions when offering DISABLEBOD & DS18B20 answers.

Rev. Ed's manuals etc are widely considered to be pretty informative, so sorry to read "I think the Code examples are pretty useless on the Basic Tutorial" ...

 

[HertzHog]

Old, many skills, self taught electronics and computing. Sorry, not all useless, but many are e.g. The first example. My program is quite sophisticated and fills the 18m2 I need the + version to progress.

 

[eclectic]

Old, many skills, self taught electronics and computing.

Which means what?

e

 

[HertzHog]

Old mid 50s. Many skills = a high powered job, I can glean and assimilate information when it is there. Formal education but electronics and computing are hobbies but with a proven track record. Resources brain, soldering iron, no oscilloscope, DMM.

 

[manuka]

How often are you monitoring the temperature reading? Which PICAXE? What power supply are you using- batteries? What's actually in your incubator?

DS18B20s draw a few mA if left on, but they can be easily switched by a PICAXE pin for overall current drain reduction. Supply reading from the PICAXE is possible, but it's debateable that you'd really need it with a switched DS18B20 (& resulting low drain), as the extra supply sensing & alarm etc could draw more current than the main circuitry. Refer here for just one (of several) past forum discussions.

DISABLEBOD is/was a (belated) command that allowed the PICAXE-08M to usefully keep running at a supply voltage below the normal factory brown out detected shut down. Using this (& other frugal) techniques, fellow Kiwi Andrew boasted he could keep a 08M awake at just 1.3 V when it drew ~1µA. It was handy for usefully trimming SLEEP drains,but it may be superfluous with the new low supply tolerant M2 range.

Stan. (of Swan's Law = "You can never have too many thermometers !" )

Extra: Your age is that of a typical forum poster, & in fact it makes you younger than many of us!

 

[srnet]

Question 1 what is the likely consequence of enabling or disabling brown out detection with DISABLEBOD, what does it actually do? apart from a reduction in power use which seems not quantifiable

DISABLEBOD, does indeed reduce current consumption and is of particular use when the PICAXE is put into in sleep mode.

It is readily quantifiable as you can measure the difference in current consumption with it enabled and with it disabled.

 

[premelec]

CALIBADC is a bit complicated but can get you where you want for an accurate READADC - a simpler method for detecting sagged battery is to put zener diode to a 10K resistor to V- with the other end of the 10K going to READADC pin - this draws some static current while the battery is up but quits when battery no longer exceeds the zener voltage - then READADC returns 0 or near 0. If you want to save power while in SLEEP you can switch an output pin to zener off. rather than using zener to V+.

I've had DS18B20s read 85 degrees on first read when started and now put in a double first read to wake them up... I don't know why 85 is the spoofed reading...

 

[HertzHog]

Battery Monitoring (just one).

Either my questions were good or not understood because no one has answered them yet so there is a challenge. Just to restate them.
A) What useful function has ever depended on brownout detection? What does it do to justify ever being on. Who uses it and why? Why is the code snippet offered still so useless.
B) Can any picaxe alone (with its program) take action at a specific sagging battery level using its internal reference. (No external supply to monitor, no Zeners, just the Picaxe resistors and code. It looks like it should but the examples are poor.)
Particularly for me, the tweaks to minimise current consumption are interesting and I'm absorbing those BUT they do not answer my questions.

I wanted to keep the discussion pure, but did you know the sex of tortoises depends on the temperature eggs are incubated at? I thought you guys would be bored with thermometers. I am pleasantly surprised with how much really useful functionality I can gets from such minimal modification to an Axe049.
HertzHog.

 

[HertzHog]

Yes Manuka, as stated. It is a battery. The problem relates to ensuring peripherals are reliable and that they do not misread and misbehave as the voltage sags which is a fact of life and systems need to be designed fail safe. Precious eggs!

 

[g6ejd]

Yes, brownout prevents the processor from entering an operating region that would give unexpected results, data corruption and programme malfunction - effectively switching it off until power is correctly restored.

Yes, using calibadc you have an internal voltage reference and so don't need any external components to compensate for falling up ply voltage from say batteries. The use of the internal reference is relatively easy to do.

 

[Svejk]

The Brown Out reset is not necessary related to a function (be it Picaxe or native PIC), it is there to provide some protection in case of unstable power supply. That is, the start up will be delayed until Vdd is bigger that Brown out threshold.

You can monitor the battery voltage with a voltage divider (to drop the monitored voltage) and use the 2048 mV internal voltage reference for reading.

However, if the eggs are precious, a redundant safety system _must_ be in place.

 

[srnet]

Either my questions were good or not understood because no one has answered them yet

Its the way you ask them probably.

If you want specific help, with a specific problem, then best to stick to just asking the questions rather than mix it up with a pile of critical stuff.

"A) What useful function has ever depended on brownout detection? What does it do to justify ever being on. Who uses it and why? Why is the code snippet offered still so useless."

The manual already gives a good summary of the function and the code snippet, rather then being useless, outlines quite specifically how to use the function, what were you expecting ?.

A fuller decription of brown out detection can be found here;

ww1.microchip.com/downloads/en/DeviceDoc/31003a.pdf

"B) Can any picaxe alone (with its program) take action at a specific sagging battery level using its internal reference. (No external supply to monitor, no Zeners, just the Picaxe resistors and code. It looks like it should but the examples are poor.)"

Thats possible for those PICAXEs that have an internal voltage reference, or you fit an external reference of some type. Then, when a low voltage condition is detected, you could put the PICAXE (X2 parts) into a permanent sleep.

 

[HertzHog]

Yes, using calibadc you have an internal voltage reference and so don't need any external components to compensate for falling up ply voltage from say batteries. The use of the internal reference is relatively easy to do.

Please can you explain how? Say 3 xAA batteries supply of 4.5 v to shut down when a test shows one goes flat e.g. At 3v.

 

[premelec]

Have you read and understood the CALIBADC command? P42 Manual 2 -

Being something of an empiricist I suggest you try CALIBADC and watch what happens to the returned result as you vary the 'battery' voltage

 

[HertzHog]

I have read, but failed to understand the calibadc command. I think it is because the example code is poor and does not show it doing useful work. Relying on the debug command stops the written explanation from being useful as it is not sufficient to teach the function without having a chip in front of you to test. At that point everything is subjective and individual chip dependent and does not help circuit planning and design.
I'm trying to develop a brown out safe failure detection for a circuit containing peripherals with a higher dropout voltage than the Picaxe. Honestly, I did try to find this information by searching first. It seems such an obvious requirement. I was surprised not to see pointers to an answer somewhere. HertzHog

 

[premelec]

Well it's 2AM here and my brain is fading but basically CALIBADC reads the internal reference voltage WITH THE SUPPLY VOLTAGE AS REFERENCE FOR THAT READING. so that will indirectly tell you what the supply voltage is when you work it backwards... The specific equations have been reported before and you might search this forum for CALIBADC for that - I've got to retire just now...

 

[g6ejd]

so something like:

symbol Vsupply  = b20
symbol Vreading = b21

check_voltage:
    calibadc Vreading
    Vsupply = 255 * 6 / Vreading / 10    ' at this point you now have your battery voltage in variable Vsupply
    if Vsupply < 3 then 'assume a lower cutoff of 3V
      sleep ' or do something elese here
   endif
   return

 

[Svejk]

I have read, but failed to understand the calibadc command. I think it is because the example code is poor and does not show it doing useful work

Also, the problem may be beetwen keyboard and seat.

You want to detect a brown out before it occurs? or you want to know what caused a reset? Monitoring the supply voltage is possible but you'll have to invest 2p and buy 2 resistors to make a voltage divider, or some other arrangements. This code will work with a potential divider Vdd-10k-pin-4.7k-gnd

#picaxe 08M2
' setup Fixed Voltage Reference to 2.048V
fvrsetup FVR2048
' setup adc to use above FVR
adcconfig 
1
do
    ' read voltage present at C.1 into variable W0
    readadc10 C.1, W0
    
    'test voltage
    if w0 < 750 then
     'do something
    end
loop

 

[HertzHog]

We are getting closer now. I think the byte variable will overflow instantly? Is the 6 due to a constant that is chip dependent, or must it be specified prior with a command? Thanks.

 

[MartinM57]

No it won't overflow. as PICAXE maths uses 16-bit integers as it evaluates expressions. Have a play with the simulator with simple test programs to appreciate how PICAXE maths works (and note expressions are evaluated left to right, and normal arithmetic operator precedence rules are not respected). Also note that 6 is not the right value for the equation for 18M2 - see Manual 2 Page 42.

Manual 2 Page 42 seems quite clear to me how to use calibadc to get the actual battery voltage despite the variable battery voltage being the reference point for the READADC reading . I would suggest you try some experiments with a variable supply to your PICAXE, some simple code and sertxd/debug statements in appropriate places

 

[Dippy]

We are getting closer now. I think the byte variable will overflow instantly? Is the 6 due to a constant that is chip dependent, or must it be specified prior with a command? Thanks.

It's lifted from the Manual2 page 42. The 6 and the 10 are explained in there. Have a read.


In fairness if a detailed explanation and full example code was given for each command then the Manual would be 5 miles long.
You will always have similar problems when the Authors know the product inside out AND try and compress the description to a brief summary. It's a tricky balance and will always be clearer to those with years of experience, so I understand what you mean.

Hopefully the FORUM can put some meat on the bones

And this is where grabbing the example and having a play on a real PICAXE can be really helpful.



I'm having trouble following this thread is we seem to be flitting around between subjects.
May I suggest we deal with them one at a time.

I'm a bit confused as to the discussion on the BOD.
The basic description has been given by g6ejd and Svejk, but one thing I'm not sure whether you have understood that it's primary purpose is for the clean operation of the actual PICAXE.

The BOD circuitry inside the PIC consumes a little bit of power, so, if you are confident with the supply you can switch it off to save power. This is handy when you are doing micropower designs and, quite often, SLEEPing the PIC.
For advanced users it is possible to use register settings to take some action as a result of the Brown Out detection, but that's for a later day.

ADC.
I think we're all talking the same thing here, but I'm not sure.
A 'standards' READADC uses the PICAXE supply voltage as reference.
So, in effect, if you read the supply voltage using ReadADC it would always read 100%.
Using a stable REFERENCE you can read the supply voltage relative to the supply voltage.
Your options are the Internal PIC references using a factor from CalibADC OR an External reference and use ADCConfig.

 

[manuka]

- did you know the sex of tortoises depends on the temperature eggs are incubated at? I thought you guys would be bored with thermometers.

Well yes I for one certainly did - eggs of our NZ "living dinosaur" Tuatara reptile are similar. In their case warmth favours males & cooler conditions females.The critical period for Tuatara gender determination seems quite short –an egg may only need to spend a few days above 22°C in order to turn out male.

FWIW forum calls for help can neglect to mention details that actually are VERY relevant to the request, & scores of postings may arise before the nature of the need emerges. For all we knew you may have been a teenager rustling up home brew under their bed...

 

[lbenson]

As noted, the byte value, Vsupply, in g6ejd's example, will not overflow because the truncation from a 16-bit value to an 8-bit value will not occur until the assignment is made--the intermediate values in the calculation will never exceed 16 bits, and the final divide-by-10 will assure that the result fits in 8 bits.

The implied 6 divided by 10 +is+ the .6 shown in the CALIBADC explanation in the manual, so it is chip-dependent. For the M2 series, the value is 1.024.

I haven't used the CALIBADC10 command, which looks like just the thing to achieve your purpose. For your purposes, 1.024 appears to me to be close enough to 1 that you can just ignore the decimal places. So the formula would be

CALIBADC10 w2
Vsupply = 1023 / w2

If the reading you get in w2 is on the order of 205, then that means you have a 5-volt supply.

This calculation only gives integer results, e.g., 3, 4, or 5 volts. If you want a decimal place, you need to adjust without overflowing.

One possible way would be to multiply the "step" value by 10, so your formula would be:

CALIBADC10 w2
Vsupply = 10230 / w2

This would give volts times 10.

Or for volts times 100

CALIBADC10 w2
w2 = w2 / 2
Vsupply = 1023 * 50 / w2

This is speculative and completely untested, so I would try it out with different known voltage values.

 

[techElder]

Personally, I wouldn't risk my turtle's sex on a homebrew temperature control system. But that's just me ...

 

[MartinM57]

No mention of controlling temperature as far as I can see...just "a very accurate thermometer"

 

[Dippy]

One prob at a time dear boy

 

[hippy]

Either my questions were good or not understood because no one has answered them yet so there is a challenge.

Part of the problem I feel is in the way you are phrasing the questions which make them difficult to answer.

It's like you are complaining that the manual which came with your tool box is useless because its description of a hammer, and illustration of its use, does not tell you how to go about your goal of building a kitchen cabinet.

Rather than asking the bottom-up question, "what use is a hammer for building a cabinet?", or "why would anyone use a hammer?", which will only lead to self-referential and self-evident answers which simply go round in circles, you need to ask the top-down question; "what tools do I need to build a cabinet", and, "how are those tools used to help me do that?".

A) What useful function has ever depended on brownout detection? What does it do to justify ever being on. Who uses it and why?

You need to first look at what BOD does. When enabled it prevents a PICAXE from behaving unexpectedly when its supply voltage falls. When disabled it allows operation at a lower voltage but introduces the risk of unexpected operation as voltage falls. You get the choice of which you want. In addition, when BOD is disabled it reduces power consumption.

Who uses it ? Most people as it is enabled by default.

Why is it on by default ? Because most people want guaranteed operation as expected from the PICAXE, and will accept that when the supply voltage drops it will stop operating completely rather than operating in a potentially unexpected manner.

Who would not use it ? Someone who wanted the PICAXE to operate at a lower voltage or wanted minimal power consumption and is prepared to accept the risk of potentially unexpected operation or has mitigated that in some other way.

B) Can any picaxe alone (with its program) take action at a specific sagging battery level using its internal reference.

Yes.

It is a two part process; determine what the power supply voltage is then take action depending upon that result. In addition it may be necessary to disable BOD to allow the PICAXE to do that rather than it stopping working as the voltage falls.

So the primary tools - the Basic Commands - you need which are provided by the PICAXE are; CALIBADC or CALIBADC10 and IF, and perhaps DISABLEBOD.

The manuals describe those commands and their syntax and give some examples of those commands being used in programs. To apply those tools you need to map what they can do to what you need and that often depends on what it is you actually need; a spanner can be used to tighten or loosen nuts ( as shown in its manual if it has one ), but it won't necessarily describe how to remove any particular nut in every situation. That's likely to be found in 'application notes' and in other people's documented descriptions of use of the tool.

For use of CALIBADC to determine the voltage of a PICAXE supply there are a number of previous forum posts including this one -

http://www.picaxeforum.co.uk/showthread.php?19217-monitor-a-picaxe-s-08m2-circuit-s-batteries-power-using-code

 

[marks]

Dam hippy beat me already
i guess i'll post this snippet anyway lol!

#picaxe 18m2    'version 2.A * marks						
#terminal 4800

'  VoltageReference.
'  0.6V     20M, 28X1, 40X1
'  1.2V     28X2-3V, 28X2-3V
'  1.024V   All other parts that support this command
'Note that this command is not available on 28X2-5V/40X2-5V

SYMBOL ADCvalue      = W1
SYMBOL Vsupply       = b4
SYMBOL D1            = b5
SYMBOL D2            = b6

Main:

CALIBADC10 ADCvalue          '(ADCvalue  = VoltageReference * 1023 / Vsupply )

Vsupply = 10475 / ADCvalue   '(Vsupply   = VoltageReference * 1023 / ADCvalue)


BinToAscii Vsupply,D2,D2,D1
sertxd (CR, LF,D2,".",D1,"v" ,CR, LF)'display eg 5.0v

pause 1000
GOTO Main

 

[HertzHog]

Is this the solution one uses?

Yes. For now tortoises are hibernating. No eggs. I want to start with a thermometer and be ready.
I think this has shown I am not alone not understanding this problem. I thought there would be an easy way no LED or resistor network needed. Thanks for pointing out the 16 bit interim arithmetic. I had forgotten that and it is reassuring for calculations. That was in the manual.

Symbol voltsx100 = w1     ' so I can avoid decimals & 340 = 3.4 volts
' N.B.    1023 i.e. number of steps x 1.024v i.e. Voltage reference (on 18m2) = 1048v
' 1048 x 10 x 5 = 52378. ' intention is to be almost the biggest number a picaxe can manipulate!

' now there needs to be fiddle which maximises precision in the numbers. No sleight of hand just note 5x2x10 = 100
Calibadc10 voltsx100 ' intermediate step at present
Voltsx100 = 52378 / voltsx100 * 2

If voltsx100 < 312 then goto ShutdownCleanly ' assumes 3.12v is the minimum level allowed.

How is that? HertzHog

 

[HertzHog]

Thanks Hippy. Personaly, I think the exposition of basic commands SHOULD show what use the tools are good for to stimulate understanding and use. When one is pre-contemplative and trying to educate and find if the tool is the right one, I think having debug in the example code snippet is just wrong. It assumes you are fiddling with a specific chip already. I think Picaxe is brilliant. Please take my comments as being there to make easy constructive improvements. I was frustrated by not finding clear usefull examples. Just showing syntax that will pass the compiler, is ok, but is not at good as it could be.
I wanted to give brown out protection for the project not the Picaxe, which because they are brilliant actually in this instance did not need it, but that is why I linked the questions. Too subtle perhaps?
Remember in searching forums there is lots of misinformation too which is why the official code snippets need to be seen to do useful things.
The 'answers' in the threads use LEDs, Zeners and resistors and pins when none are needed I think.
HertzHog

 

[lbenson]

The 'answers' in the threads use LEDs, Zeners and resistors and pins when none are needed I think.HertzHog

Those answers may have been provided before "CALIBADC" was available, and may still be applicable for parts on which it is not now available. Things change over time.

 

[Dippy]

Unfortunately it was so subtle that no-one understood what you were trying to ask.
That was one reason why I , in my previous post, felt that we were flitting between subjects. Your linkage was not clear.

Why didn't you simply ask something like; "Can I use the BOD feature to switch external peripherals if the battery supply droops below a certain level?"
And then give a brief and clear explanation of your setup and your requirements.
This makes it unambiguous and nice and clear for the people that give their time FOC to help you.
I appreciate that Stan will want to know your inside-leg measurement before he answers but you have to accept that


I agree that some examples in Manuals are a little 'brief' , but supplying snippets for 80% of people's Apps would require a book.
For something that costs almost nothing you can't expect a book FOC too.
This is where the Forum is useful. Free access to people who know their stuff.
So, be gentle, be clear and be polite. Don't bite the hands that feed you.


Also you must bear in mind that many posters are as new as you , so some of the posted 'answers' may not be the best answer and shouldn't be considered as a definitive exposition but rather a qualified suggestion.
And remember; some 'answers' to these types of question were before PICAXE had features wrt Internal references.
Therefore some of these things are a little out of date.

You need to understand that ADCing is RATIOMETRIC and therefore something has to be stable to perform a ratiometric measurement.
Similarly you should realise the possible need for potential dividers. Why?
Some people have suggested an LED as a reference, but I wouldn't. Obviously you'll know why.
If you don't think resistors are needed then explain or ask; don't be so subtle.

 

[srnet]

Remember in searching forums there is lots of misinformation too which is why the official code snippets need to be seen to do useful things.

Thats really a view from an individual perspective and not one have have seen expressed often.

One of the good things about the current manual is that it is kept brief. If its read cover to cover by newbies, then whilst most of it might not be relavent to their immediate needs, seeds are sown in the memory which will be so useful later. Make the manual longer and the code snippets longer (and more complex to read\understand) then most of this seed sowing is lost.

Maybe there is a demand for an additional and much longer, more detailed manual, with real working examples, with circuits, but the current manual is about right.

You could always offer to do a major rewrite for a new manual, maybe some would even buy it.

 

[hippy]

Personaly, I think the exposition of basic commands SHOULD show what use the tools are good for to stimulate understanding and use.

There's always going to be debate and disagreement as to what any particular documentation should include or exclude.

Vehicles are a classic case in point; the owners manual will show where things are, tell you how to keep it clean and provide a basic technical resource for essential things ( type of fuel, tyre pressures, service intervals ), but mechanical details will be found in separate technical documents, Haynes Manuals (R) and the like, "how to drive" will be in another book, "road safety" and "highway legislation" somewhere else. There's unlikely to ever be a single book with all that information in and most would not actually want such a book as, from some specific aspect, the great majority of that mighty tome would be irrelevant for their needs.

Remember in searching forums there is lots of misinformation too

I wouldn't say there is a lot of misinformation, more that there will sometimes be information that may not be particularly useful to what someone else wants to do, perhaps isn't applicable to other cases.

As with most things there will be numerous ways to do something, each having their pro's and con's, and possibly dependant on situation or circumstance. Take finance for example; there are plenty of details on what different financial instruments are and how they work but deciding how best to save for your future is a somewhat different question.

 

[Paix]

At risk of repetition, hesitation or deviation, I seem to recollect a thread some time ago where some museum, trust or some-such had a very expensive set up to protect something temperature sensitive (like eggs) that was at risk of failure and a PICAXE backup proved altogether more suitable. Was this something that Stan or Westy wrote. Probably six months or more ago?

 

[HertzHog]

Well I was only trying to show the Basic commands to have a clear purpose.
The original code snippet did not explain how it could have a simple vital useful function. I have put new code in the comment section of Calibadc10. Remove it or enhance it?
My humble thermometer is now failsafe even as the battery goes flat. How many projects need to incorporate or consider that sort of idea? Just uses 1 word variable (could be borrowed space from another word word variable) and 2 lines of code and then choose to GoSub either of the two option routines VoltsAdequate or BatteryFailing.

calibadc10 SupplyVoltsx100 
SupplyVoltsx100 = 52378 / SupplyVoltsx100 * 2
If SupplyVoltsx100 > 425 Then ... 'It is above 4.25 volts
  Gosub VoltsAdequate
Else
  Gosub BatteryFailing
EndIf

HertzHog
P.S. As a newbie to all this, I suggest to the moderators a thread for improvements to make more useful example code snippets. But perhaps I am in a minority of 1 in thinking the manual could be enhanced. Sorry to have stirred a hornets nest.

 

[Dippy]

Lordy, you are not in a minority of 1....
As I have said TWICE now that I think some examples and explanations could be improved.
Others have made comments in the past.
Have you actually read the posts above?
However, the general problem is ; where do you draw the line in terms of range/complexity of the examples?
Where do you draw the line wrt size / skill-level-assumed / size-of-manual? All for Zero pence cost to you too.

I thought there were some PICAXE books around?
Will you part with cash for one?

 

[eclectic]

At risk of repetition, hesitation or deviation, I seem to recollect a thread some time ago where some museum, trust or some-such had a very expensive set up to protect something temperature sensitive (like eggs) that was at risk of failure and a PICAXE backup proved altogether more suitable. Was this something that Stan or Westy wrote. Probably six months or more ago?

@Ian.

http://www.picaxeforum.co.uk/showthread.php?19801-Costly-sensor-failure&highlight=snails

e

 

[geoff07]

I think many agree that the manuals could be improved - but in the last three years Manual 2 has grown from 867kb to 1.2MB, which is a lot of new info and is a clue to the firmware work behind it, so I suspect Rev-Ed are working flat out just to keep everything up to date. If you have a particular technique that works, you could put it in a blog entry.