Notifications
Clear all

Nano Power Supply Substitution

27 Posts
4 Users
7 Reactions
191 Views
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

@davee 

My 'sermon-style' answer above was...

... much appreciated. Sincerely.

I understand the amount of effort, like this,

...what I discovered about the kit, by following the included link, and also the GitHub entry, ...

and thought you (and others) put into your posts;  So I read them with great interest.

Hence, the answer assumed that you were trying to construct the kit, and were looking for a means of powering it.

A reasonable and correct assumption. I did, in fact, assemble the kit by following the instructions up to the final step of testing the control code for the kit.

The kit was designed for 2 x 18650 Li-ion cells connected in series, which could be substituted with a mains power supply with similar power output characteristics to the 18650s, namely 7.0-7.5V at a minimum current capability of 3 Amps.

The rust on my circuit analysis skills prevented me from really appreciating this. Somehow I felt  3 amps was high. But now, after a few measurements, I understand it. Under load, the servos draw substantially more current and have recurring spikes, hence the higher current requriement is necessary.

The result of this is I'm convinced I need to get a bench power supply rather than scrounge around for substitutes.


My concern regarding the 'lack' of a complete schematic to fully describe the system is still an issue. ... For example, where is the power wiring for the servos?

You gotta love some of the stuff you get for documentation. The shortcuts used are remarkable.

Physically, we're on familiar ground. The servos use Dupont female connectors, (brown-red-orange) that mate to male header pins connected to female Dupont connectors that the Nano plugs into. Essentially, a pass-through connection.

However, the wiring diagram uses a shortcut that only shows the orange signal wire connection for  each servo. The power connections aren't shown because ... you know, they're glued to the signal wire and ... of course they go, you know, to the right color/numbered pins. Obvious. Oh, yeah, and the sckematic shows what those pins are connected to. (You know I did a continuity check for the fun of it. It's good practice for me for now.)

wiring

I know this made sense to somebody somewhere. It's just somewhere I've never been to.


(And apologies if you are already familiar with what I am about to describe.)

I am, but have never done it. Still it's worth reading. These are considerations that are part of  creating or modifying a circuit. From my perspective, it's important to for me understand the circuit I'm working on.

I'm fair certain this will be an incremental upgrade process.

The one who has the most fun, wins!


   
Ron reacted
ReplyQuote
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

@davee

Posted by: @davee

I confess, I can't imagine why you want to do that, and I would normally try to dissuade you, but if you are looking to modify the wiring to the Arduino supplied with your kit, then it should be possible to replace the connections from the 5V regulator on the custom board provided with the kit, once you have identified them, and are careful to avoid reversing the polarity.

What? No! Really?

All I wanted to do was run a pair of wires from the power rail to the shield power connector. I thought that because I could (and have) run 4 servos off the breadboard power supply I didn't need the functionality of the power management circuit. The voltage and current from the breadboard power supply were sufficient and needed no regulation.

As you pointed out, the current demand would prevent that. In fact, I tried it anyway with no success.

A pity but surely not hard to imagine.

The one who has the most fun, wins!


   
Ron reacted
ReplyQuote
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

@davee 

gimme time to absorb the rest of this.

(cuz I'm slow. And lazy. But handsome.)

The one who has the most fun, wins!


   
ReplyQuote
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

Addendum: my criticism of the documentation LK Cokoino robot arm regarding the servo power connections did not take note of the Trouble Shooting Guide. In there, under issue #4 there is a more detailed picture of the connection

servo detail

The one who has the most fun, wins!


   
ReplyQuote
(@davee)
Member
Joined: 4 years ago
Posts: 1924
 

Hi @tfmccarthy (and Ron @zander),

Thank you for your kind and useful replies.

------

  I confess to coming from a development background that suggests that you try to start with something that works, and move incrementally, trying to only make one change at a time.

So had I bought the kit you chose, I would have started with that kit, assembled and (hopefully) got it to work as documented 'out of the box', then played with it for a while, before tweaking each bit I didn't like, one at a time.

Of course, this is only a general scheme, and reality + lack of patience, often gets in the way. But I was worried that if you try to change too much at once, you would get stuck ... It may not be obvious, but the kit designer has put some care into the design to achieve a specification, but that specification, and hence the design is not the same as you would probably adopt, if you were starting from scratch. The difference in the two designs is rather more than is easily accommodated by the 'just 1 change at a time' philosophy.

Of course, I know nothing of your skills or background, so please don't think I am judging you ... I am just being my usual sceptic self, who tends to take the view that 'anything that can go wrong, will go wrong', and fixing something with 2 faults, that are present at the same time can be very much harder, than the total work of fixing 2 faults, but only one is present at any one time.

So, with that 'general philosophy' comment as a background to my eccentric approaches to life ...

--------------------------------------------------

 RE:

  re: I'm trying to replace the two 18650 batteries with the breadboard power supply 5V

I confess, I can't imagine why you want to do that, and I would normally try to dissuade you,

Perhaps I should clarify my comment.

All of the dev boards of the type used in this discussion (Arduinos, etc.), that I can immediately recall have a pin, sometimes labelled something like "Vin" ...

Of course, you may need to do a little sleuthing to figure out which one it is on any particular board, as naming schemes are far from universal and fixed.

The 'official' Arduino documentation I referred to in my last sermon, clearly labelled it, and even provided an appropriate comment:

image

Other board suppliers, particularly those providing clones, may be less helpful. (Of course, the clones may be kinder to your wallet.)

The important clue to note is that this pin accepts a small range of voltage. Whilst there are exceptions and variations to every rule, in general, the microcontroller at the heart of these boards is usually designed for a specific voltage ... typically 5V with the older design boards, 3.3V with the more recent designs.

Thus, the specification input of 7V to 12V implies this pin connects to an on-board regulator, and typically also some other protection circuits, etc., to try to give the all-important microcontroller a clean, safe power supply, and the best chance of reliable operation.

Your breadboard supply may have the same type of regulator chip as the one used on the Arduino, but it is connected with longer wires, (which means more inductance, risk of EMC problems, etc.), and using it, instead of the dev board's own regulator, is bypassing the protection, and other tricks that are built into the dev boards to reduce headaches for the user.

--------

So combining my 'philosophy' and the specifics of driving contemporary dev boards, like Arduinos ...

I can understand why you may wish to replace the pair of 18650 cells with a mains power source ... I have never meant to dissuade you from that direction, and if my comment failed to explain that point, I apologise for not being clearer.

Based on my 'philosophy', combined with my understanding/imagination of the kit you bought, and based on the available documentation, I thought it would be easier and less risk of frustration, by initially using the kit in the 'out of the box' format, with minimal changes, whilst you get more familiar with it.

As I have previously tried to explain, the design is somewhat different to the 'usual' approach described by Bill and others. Conversion from one approach to the other is certainly feasible, but it breaks the 'one change at a time' rule, and requires understanding of both approaches whilst you attempt the conversion.

Hence, I suggested originally, and I continue to suggest, start by keeping the kit 'intact', and only replace the battery with a power supply that can provide the same power (in terms of voltage and current) as the batteries.

I think getting a 'bench' power supply is an excellent idea, assuming you wish to continue developing new designs etc. To give yourself some flexibility for the future, then obviously you may wish to increase the maximum voltage and current it can provide, but the important 'setting' for this case is about 7.5V at more than 3A.

In commercial designs, microprocessor based computers and microcontrollers have often been provided with 'minimised' power supplies, whose current capacity is 'just about sufficient', to minimise cost, weight and size of the total unit. Such units often prove susceptible to intermittent crashes, power supply failures, and so on, whilst those with 'over-sized' current capacity are typically reliable. Hence, excepting occasions where a small increase of cost, weight, etc. is totally unacceptable, I always recommend providing a healthy margin!!

-------

As for your total project aspirations, I do not know how far you decide to take it, but as you have survived more than one of my sermons, hopefully with nothing worse than minor scars that will soon heal, I suspect that you will eventually migrate to a larger structure, requiring more powerful motors, larger power sources, and maybe an approach closer to that described by Bill (@dronebot-workshop) and others.

I hope this helps a little ... best wishes, Dave


   
Ron reacted
ReplyQuote
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

@davee, @zander, et alia 

Dear Reverend @davee,

(Get it? Sermon - Reverend? Funny, I am!)

"Lay of the land" speech follows ...

Like so many here, I'm a retired engineer, who spent a long career writing software and holds a degree in Electrical Engineering. The truth of the matter is, I haven't used my Electrical Engineering training in decades such that I actually womder if I ever did earn the degree. Now that I'm retired I'm going back to play with the new toys but I have to relearn my basic electronics/circuit analysis. Until then, I'm a novice; a knowledgeable novice but still a novice. Software is my real forte, but I have a strong background in microcontrollers and test engineering.

(When I origianlly wrote this I wrote a bunch of words about how I do things, etc. until I realized ... nobody cares or wants to read that. It was really well written, informative, and funny! But nobody asked and nobody cares. Folks will pick up how I do things by me doing them. So there! That'll show me!)

I ordered a bench power supply but while I'm waiting for that I can extract the Nano and shield for testing. It turns out I have a passive buzzer and a IR receiver so I should be able to replicate most of the shield functionality, take some measurements, and see where that takes me.

Lastly, I have no experience with the Nano but I think you can power it using the 5V GPIO pin. From my perspective, the information is contradictory. @davee references the documentation that seems to indicate that the pin is output only, while the forums indicate it's approved for input power. Also, logically, from @davee's analysis, you can't use the 3.3V or 5V GPIO pins to power the MCU; you can only use the USB or the VIN pin (using 7 - 12V). That doesn't seem right. And from what I've read, to use the 3.3V pin you need to cut a jumper that disables the USB.

To sum up, the way forward for me is to perform some tests and measurements of the isolated components and when the power supply arrives, assemble the complete kit and test that.

And remember, nobody really cares but you, so you better enjoy doing it.

The one who has the most fun, wins!


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 8046
 

@tfmccarthy Slow down pardner. Do NOT get your board info especially power from random internet locations. Nano data is at HERE  see pic for overview. The NANO is a 5V device, the VIN pin can handle 7 to 12 V but I have seen specs say it is really 5 to 12V (the LM1117IMPX-5.0 datasheet will have the definitive answer but I am not going to look at it as 5 to 12 serves me well). The pic is from the arduino.cc site. It can be seen that the 3.3V and 5V pins are output only, there is also one other pin that is 5V on the ICSP, but that is NOT for normal use. I am enclosing Arduino documentation screen grabs that show very clearly there are ONLY 2 'normal' power input points. The reason I say 'normal' is that the ICSP also has a 5V in and some yahoo might try to say that is also a 5V input. 

Screenshot 2025 01 20 at 14.45.22
Screenshot 2025 01 20 at 14.53.17
Screenshot 2025 01 20 at 14.42.46
Screenshot 2025 01 20 at 14.51.30
Screenshot 2025 01 20 at 14.52.15
Screenshot 2025 01 20 at 14.58.38

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, 360, fairly knowledge in PC plus numerous MPU's & MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 8046
 

@tfmccarthy FYI, @davee is seldom wrong, but this time he is right. The Arduino datasheet has VIN at 5V to 12V but since this is a 5V LDO regulator, the input HAS to be a bit more than 1V higher than the output so my reading suggests that 7V to 12V is the correct answer which is what other Arduino documents say.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, 360, fairly knowledge in PC plus numerous MPU's & MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
ReplyQuote
TFMcCarthy
(@tfmccarthy)
Member
Joined: 7 months ago
Posts: 279
Topic starter  

O brothers let's go down
Let's go down, come on down
Come on brothers let's go down
Down in the river to pray

Reverend @davee,

I confess to having congress with the impure Arduino forum.
I was enchanted by the Nano 5V sirens.
I couldn't help myself.
And everyone seemed to be doing it.
I didn't know.
But I want to reform and get back on the right path.
Can I be saved?

This post was modified 3 weeks ago by TFMcCarthy

The one who has the most fun, wins!


   
ReplyQuote
(@davee)
Member
Joined: 4 years ago
Posts: 1924
 

Hi @tfmccarthy,

   The sermon reference is only meant as a comical indication that too many of my replies are long, boring spiels, albeit I hope the reader gains some useful information. 🤔 🤔 🤔 

The bad news is that this reply contains quite a lot of detail, so I advise a comfortable chair and adequate beverage supply. Don't worry if you don't understand it all, on first read ... take it a bit at a time, and please query anything that doesn't make sense. It could well be a typo on my part ... my typing ability is terrible, and it is very difficult for me to see my mistakes, as my mind automatically sees what I think should be on the screen, not what is actually onscreen.

For clarity of maintaining a conversational flow, I have accidentally duplicated some of Ron's comments ...  I hope the duplication reinforces the point and my apologies to Ron. I hope there are no contradictions.

And please accept my apologies if some or all of it is already familiar to you. I do not know what you have correctly grasped, but as I would like to minimise your confusion, all I can do is to try to be as comprehensive as possible.

------

Unfortunately, as Ron (@zander) has indicated, you seem to be a little confused.

For example:

Re: I think you can power it using the 5V GPIO pin. 

Sorry, but this statement is completely wrong for every microcontroller, the chip at the core of development boards by Arduino, Espressif, Raspberry Pi and thousands more.

-------------

GPIO is short for General Purpose Input Output. A microcontroller combines a physically small computer, including memory, processor and so on, with peripheral circuits that facilitate connection with 'real world' objects including servos, buzzers, LEDs and countless others.

To understand what it is meant by that, I think we need to backtrack a bit...

----------

In some cases, some of the microcontroller pins will be dedicated to a special type of connection. For example, some microcontrollers have a camera interface, in which a group of the pins have a specialised circuit to facilitate the flow and control of data from a camera sensor into the microcomputer section. This approach enables very high performance processing to be included on the chip, but obviously these pins and associated circuitry will be wasted for an application that does not need to connect to a compatible camera sensor, as that is the only task that matches the circuitry inside the chip.

-

By contrast, there are countless external circuits, which require computerised control, but are less demanding in their interface requirements. The SG90 servos are a simple example, as their only control requirement is for simple timed logic pulses with an amplitude of around 3-5 volts. This is just one of many applications that are electrically compatible with the well-known 74 series of logic gate chips, whose origins from Texas Instruments date back to around 1970, and whose updated versions are still in popular usage.

Hence, most microcontrollers include a number of pins whose electrical characteristics are compatible with connecting to the appropriate 74 series family of chips, and other chips that have also adopted the same electrical characteristics.

However, each of the 74 series chips have a single fixed configuration.

So taking the electrical ubitquitous analogue of "Hello World" in logic chips as an example .. the 74HC00 pinout, which also shows the internal logic, is

image

(from datasheet at https://www.ti.com/lit/ds/symlink/sn74hc00.pdf)

The diagram shows the chip has four 2-input NAND gates, with pins 1 and 2 as inputs, and pin 3 as the output for the first of four NAND gates, and so on. Power, typically +3.3V or +5V is applied to Pin 14, with Pin 7 connected to ground (0V).

Microcontroller chips will similarly have fixed power input pins, typically labelled VCC and GND.

But to allow the same chip design to be used in a large number of applications, some (often many) of the pins will not be fixed as 'input', or fixed as 'output', but instead designated as GPIO.

Each GPIO pin has an internal (to the microcontroller) sub-circuit, which allows the pin's characteristics, such as "Is it an input or an output?", to be set by a software instruction. In principle, such choices can be continually changed by the microcontroller's programme, but in many cases the programmer will arrange the fate of each pin to be set once during the boot-up code, and leave it unchanged thereafter.

The Arduino C/C++ programming suite includes instructions for this purpose; for example, see:

https://docs.arduino.cc/language-reference/en/functions/digital-io/pinMode/

-----------------------------------

Note that practically all of the above refers specifically to the microcontroller chip itself, as against the whole Arduino Nano or similar board. e.g. in the photo below, it is the black square, left of centre, which is rotated to 45 degrees to board edges.

image

The photo also shows that the majority of the chip's pins, which project out from its edges, are connected to tracks that go straight to pins along the edges of the board. In other words, most of the microcontrollers pins are directly accessible to the user connecting to the board's pins, with no intervening circuitry. There will however be few exceptions to this trend; I'll mention a couple of the most important ones.

-----------------------------

The Arduino Nano was among the first products designed and marketed by Arduino. This has presented a challenge to Arduino, because chip technology has changed dramatically over this period, to the extent that the original microcontroller is now a museum piece, but Arduino would wish even their longest time users, who may have built the Nano into a product or application, to continue to buy Nanos for current production and maintenance, with minimal pain of redesign, etc.

Hence, they still produce boards with essentially the same physical characteristics, pin designations, etc., but the actual circuit on the board, and in particular the microcontroller, may be different from that of the first batch of boards. Consequentially, the Arduino website shows more than one possible schematic for the Arduino Nano, reflecting the alternative designs that have been shipped.

The 'Nano' has also been adopted by many 'clone' manufacturers, and so there are almost an infinite number of possibilities. In most cases they will probably be interchangeable, but there will be exceptions, so checking before applying power is advisable, and there will always still be a risk of being caught out.

-------------------------------

The earlier Arduino Nano boards used a microcontroller based on 5V logic. That is 5V power had to be supplied to the microcontroller's VDD (or equivalent) power pins, and the logic input and output pins, most/all of which will be GPIO pins, would adopt 5V logic levels, so that a High logic level can be up to 5V.

At least some of the more recent boards have a 3.3V microcontroller, so that power must be 3.3V, and the highest voltage expected from a GPIO pin output mode will be 3.3V, and the highest voltage that should ever be applied to a pin in input is 3.3V.

Although, I think the SG90 servos can be directly connected to either a 3.3V or 5V GPIO pin, without making any changes, other peripherals may not be so accommodating, so it is important to know which logic levels are appropriate for the actual board you are using. Small 'Logic Level converter' boards are readily available if required.

I do not personally use Arduino Nanos, so I am not the best person to answer questions about the relative chance of buying a 3.3V or 5V board. My understanding is that both variants are still in the marketplace, but whether that applies to both boards from Arduino themselves, and to the clones, I don't know. Any seller SHOULD make clear which type their own board is, but in the clone market, anything and everything is possible.

Because boards, like the Nano, may be either 3.3V logic or 5.0V logic level, you will sometimes see diagrams, text, etc. which mentions 3.3V or 5.0V in relation to a GPIO pin. This does not mean it is a board power input or output ... it is just a reminder to a unit designer adopting that board, to ensure anything connected to that pin is compatible with that logic level voltage ... breaking this rule may mean magic smoke will be emitted, and/or the pin is internally damaged!

(If the Arduino pin is 5V logic, and the peripheral is 3.3V logic, the magic smoke comment may apply to the peripheral.)

------------------
Many, maybe all, of the 'genuine' Arduino boards (including, but not just the Nano) have an onboard regulator, which typically accepts a range of voltage from 7V to 12V. (Of course, you should check the specification for any board you use.) If the board is available with 3.3V and 5.0V processor versions, then the onboard regulator(s) will be chosen appropriately, reducing the amount of change required for an end user.

I usually recommend powering any such boards by this route, partly because the board manufacturer will have chosen the appropriate onboard regulator to match the microcontroller. However, there are other advantages as well, which I discussed in a previous sermon.

---

If the board uses a 3.3V microcontroller, then the voltage regulator may be able to cope with power input voltages down to about 5V, whilst for a 5V microcontroller, the voltage regulator will need at least 6.5V, and preferably about 7V. This is because the type of voltage regulators used, require about 1V to 1.5V 'spare' for their internal voltage, plus most boards have a protection diode, to save the board from destruction if the polarity of the power becomes swapped, which 'loses' about a further 0.5V.

--

Note this also implies that the existence of (say) a board pin marked 5V, does not signify whether or not the microcontroller uses 5V.

---

Although the board may accept (say) 7-12V, if you have a choice, aim for nearer 7V, because the 'excess' volts result in increased heat dissipation in the voltage regulator. The effect of this increases proportionally with the current demand, which is a 'highly variable' quantity, dependent upon programmme code execution, connected peripherals and so on. When developing a system, occasionally touch a finger on the regulator to measure its temperature. If it hurts your finger, the regulator is more likely to fail prematurely, so some modification is likely to be prudent.

(I disclaim responsibility for any injuries caused by this method ... if this risk concerns you, please procure a temperature measuring device.)

------------------

Many Arduino and similar boards with 3.3V microcontrollers actually have two voltage regulators, the first regulating 7-12V down to 5V, and the second regulating the 5V output of the first down to 3.3V.

Many such boards also have pins labelled 3.3V and/or 5V, which provide the user with access to a supply of the indicated voltage from the appropriate regulator. This is intended to supply peripheral units and components that provide extra functionality or interfacing.

In rare cases, one of these pins may be usable as a power output, and as a power input, but it is usually only one way, for a given pin. Checking the documentation, and if necessary the schematic of the board is the only means of deciding. The Arduino Nano diagram I discussed in the previous sermon appeared to be clear as to which pins were input or output, but please remember this is describing a 'genuine' Arduino Nano, of a specific 'generation'.  It might not be valid for other generations or for any of the clones.

--

As a simple example of how to use a power outlet pin, adding a push button to a system can be achieved using a resistor (say 10kOhm) and a push switch connected in series. The free end of the resistor would be connected to 3.3V or 5V board output pin, chosen to match the microcontroller, the free end of the switch connected to GND board pin, and the switch/resistor junction pin connected to a free GPIO board pin. When the switch is open, the GPIO pin will 'see' a High logic level (3.3V or 5V depending on the supply pin chosen), and when the switch is closed, it will 'see' a Low (0V). The software program should initialise that pin as an input, and it can then read the High or Low value by calling the appropriate function.

see https://docs.arduino.cc/language-reference/en/functions/digital-io/digitalread/

Remember the on-board regulators are usually low current, say 0.7 - 1.0 Amp maximum, and a substantial amount of that current may be consumed by the microcontroller, leaving only a current capacity for add on circuits. It is not feasible to give precise figures without considering a specific unit design, but 100 milliAmps is sometimes mentioned as a maximum. Ideally, I would aim for nearer 10 mA maximum, but I tend to be overconservative on such design aspects.

----------------------

In my previous sermon, I conveniently ignored the four pins in the Arduino Nano document I discussed, labelled ICSP -- In-Circuit Serial Programming.

To be honest, I haven't read the Arduino documentation about these pins, but I am aware ICSP is an acronym used elsewhere as well, e.g. by the major microcontroller manufacturer Microchip.

It is an interface connection 'standard' to enable developers to program and debug microcontrollers when connected 'in situ' in a unit, using the minimum number of wires etc. It is not used when the developed product is in normal usage. For most Arduinos, this capability is achieved by the USB link, but in the wider world, a USB link is not available, and this is an interface only requires 4 extra pins to the PCB, which is cheap enough to be fitted to production units, even though it maybe 'superfluous'. It probably allows service personnel to 'refresh' the software in the field, should an unexpected problem arise, which could prove to be a lifesaver for some companies.

I confess to not having done any homework to find out about this particular interface implementation in the 'Arduino Nano' context, but I doubt if it offers you anything essential that cannot be achieved by other means, since the Arduino interface is well thought out, so my initial advice is to ignore it, at least for now.

--------------------------

I am sure there are many other issues to discuss, but this sermon is already too long.

I am always hesitant to recommend anyone buys something, as I do not want to encourage anyone to spend their hard-earnt cash, but you might consider the merits of leaving your kit 'intact', because it is designed to be wired in a particular fashion, which is rather incompatible with the common approach for developers starting with a 'clean sheet' design. Instead, maybe get a 'spare' Nano for experimenting with, and build up from there. With a little experience, you will find it easier to port your ideas to modifying the kit, should this become the appropriate way forward.

(I should mention, because the Nano is quite an old design, inspite of updates, some people might suggest considering an alternate. This will further complicate things for your present project, so my personal advice is to stick to a Nano, providing it will not break the bank, if you decide to retire it some time in the future, for a 'shiny' replacement, that will bring a raft of new possibilities and problems. Either way, the rate of technical update means that the shiny replacement may not even be on the market now, so looking too far ahead is often pointless. )

Bill has made lots of excellent videos on different aspects of using Arduinos, which are always clearly explained ... some may use an alternative Arduino board such as the UNO, but in many cases, the only changes required are finding equivalent pins to wire to, plus refelecting any pin number changes in the pin definition lines, near the start of the programme. If this last sentence sounds a little daunting, don't worry ... just ask a question or two at the appropriate time!

Best wishes and good luck, Dave


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 8046
 

@davee Wow, are you really that arrogant.  Had you not insulted Tim so many times I might have been supportive of another of your 'show off' sermons. But you are unbelievable. To bad this isn't the big forum, there we can block other users. You would be my FIRST choice.

I understood what he meant when he said GPIO pin and I bet a lot of others did as well. We are hobbyists not employed engineers doing the equivalent of sitting around a table drinking coffee and 'shooting the bull'. We at least in the new world often use words that may be technically wrong, but we understand what is meant in the context and if we didn't we would simply ask. A very short question followed by a very short clarification, we would NOT use insulting language.

It's 4AM where you live but you are still online. Why? Because you are afraid of what I might say that you have told me in confidence but I do have class so will only repeat those things to those who PM me (except for your little followers who you have fooled)

You really need to seek help.

 

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, 360, fairly knowledge in PC plus numerous MPU's & MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
ReplyQuote
(@davee)
Member
Joined: 4 years ago
Posts: 1924
 

Hi @tfmccarthy,

 Re I was enchanted by the Nano 5V sirens.

Sorry, I have assiduously avoided such temptations, because I am afraid it is incompatible with my calling, and hence I do not know the consequences. 😋 

 

Presently, I am not even completely sure if you have a 5V or a 3.3V Nano! Looking at the schematic drawing for the IR and light sensors, they certainly should have supplied a Nano with a 5V microcontroller, but this feels like circumstantial evidence, rather than the direct evidence I would like to see. (My latest sermon attempts to describe the reasons I am saying this.)

Perhaps you can attempt to work through my sermons, not as penance, although they will undoubtedly be painful and punishing, but to determine exactly what you have, and the way forward.

Part of the problem is that your kit has been carefully designed to achieve the robotic model, using circuits, components, etc. which are incompletely defined, especially if you do not have the actual kit to double check the diagrams with reality. For someone building and programming the model as described, the uncertainties tend to cancel each other out, so they are not important, in the same way that many people can drive a car, without having a clue how turning the steering wheel causes the road wheels to point in a different direction.

However, if you decide to radically modify the front suspension on the car, without understanding the steering mechanism, problems and questions are likely to arise.

Hence, I have recommended using the kit as described, excepting for replacing the batteries with an equivalent power supply, if you wish.

And in parallel, start to learn about microcontroller based boards, probably initially choosing to stick with a Nano for obvious cross-compatibility reasons, but building up your experience from an independent base, such as following Bill's videos, etc. (There are, of course, other sources, including Random Nerds and TopTechBoy, who also appear to take care to produce good quality material, to supplement Bill's.)

You should then begin to understand a lot more, and be able to port that experience back to the kit.

Perhaps this is a longer term project than you first envisaged, but I think it will pay dividends in the longer term, assuming you continue to expand your horizon.

Best wishes and good luck, Dave


   
ReplyQuote
Page 2 / 2