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Re: Electronic experts - BLUETOOTH
Posted:
25 Feb 2021, 17:07by expresso
Nice - more reasons to leave it alone
Re: Electronic experts - BLUETOOTH
Posted:
26 Feb 2021, 09:49by rickystyx
Irving wrote:One major caveat to the diagram on how to connect the BT adapter negative ground (black) wire.
If you are using an external buck (down) converter DO NOT power it directly off the main charger supply unless it is an isolated DC-DC converter. If it is non-isolated, connect the + input to the PL8 + (red) input only and be very careful that the - (black) connection of the buck converter does not come into contact with the - input to the PL8. Better, for safety, use a stand-alone isolated 5v USB charger, a stand-alone 5v USB powerpack, or a 3 x AA cell switched battery holder and do not connect the negative side to the negative power input.
Now, I know there are those that say they've wired it directly and it works, and yes it will, most of the time. But it is a problem waiting to happen...
The negative input to the PL8 goes to a pair of parallel 40A fuses, a MOSFET isolation switch and a high frequency noise filter BEFORE it becomes the internal 0v rail and ground connection on the 3-pin remote control connector. So connecting the BT ground to the negative power input ground bypasses all of that and under fault/overload conditions and/or when doing high-power discharge into a dummy load, that connection can potentially become the main current flow in or out of the PL8 which is almost guaranteed to do some serious damage to the BT adapter, the PL8, the wiring and/or the local environment...
So asking what to me seems an obvious question - wouldn't that be the same problem if I take the supply from the same place internally which is what I thought was the idea? So if taking the supply internally where would you supply the DC to DC converter from if not from the charger's input?
Woody my BT's have arrived thank you for doing all that for me - just awaiting the supplies now but it will be good to sort out where they should be powered from before I cause problems - so Red goes to the DC converter 5v plus output and the plug goes in place of the USB connection on the back of the PL8 correct?
Re: Electronic experts - BLUETOOTH
Posted:
26 Feb 2021, 12:06by Burgerman
Mines (5v supply) is wired direct to the 10 to 30V power input internally by soldering to the board. Been that way years. No problem so far. If thats wrong I would also change it. Better safe than sorry I suppose! But again, dont know where!
Re: Electronic experts - BLUETOOTH
Posted:
26 Feb 2021, 17:55by Irving
Re: Electronic experts - BLUETOOTH
Posted:
26 Feb 2021, 18:45by rickystyx
Thank you - I will take the top off one of my PL8s and have a look now - This will make life so much easier for me if it all works
Re: Electronic experts - BLUETOOTH
Posted:
28 Feb 2021, 04:24by snaker
Today I start making my new BT box. Because the box is very small so I should call it BT cable.
Making an external BT cable is very simple and easy. You do not need to open the charger case. And it is 100% SAFE.
The first image underneath shows all components that I will use:
1. A half of an usb cable. It will be plugged into an usb socket on a 5V powerbank.
2. A half of a futaba (servo) cable. It will be plugged into the 3-pin hole on the PL8 charger.
3. A piece of prototype board. It fits the box (number 4).
4. A box 55mm x 35mm x 15mm that contains the prototype board (number 3).
5. A HC-06 bluetooth module.
6. A schottky diode. I use 1N5819 1A rated because it is the lowest Amps rated sold here. If you could find another with lower amps e.g 100mA, it might be better.
7. A header that will hold the HC-06 BT module (number 5). It is a piece of a long header.
8. A solid tinned wire that will be used to make tracks on the prototype board (number 3).
There are 2 ways to wire all components together:
- Soldering them inline as BM did.
- Soldering them on a prototype board.
I prefer using prototype board because it is more compact. The downside is that it requires a bit more accessories. The tracks on the prototype board look like in the second image. My dad will watch it while soldering components on the board.
Re: Electronic experts - BLUETOOTH
Posted:
28 Feb 2021, 06:12by Burgerman
I just soldered the diode across the pins on the BT board. Then took 3 wires away from it. No complication of any extra circuit board or anything needed.
Re: Electronic experts - BLUETOOTH
Posted:
28 Feb 2021, 10:31by snaker
Re: Electronic experts - BLUETOOTH
Posted:
28 Feb 2021, 11:05by Burgerman
Doesent it kind of defeat the object of the excersize to have 2 extra boxes and needing a USB connector to power it all?
If you are just a tiny bit braver, fit it inside, theres nothing to see or plug in?
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 02:27by snaker
Burgerman wrote:Doesent it kind of defeat the object of the excersize to have 2 extra boxes and needing a USB connector to power it all?
If you are just a tiny bit braver, fit it inside, theres nothing to see or plug in?
In my case, PL8 always sits on a desk. It is powered by huge and bulletproof 1.500w supply which sits on that desk too. The combo of BT cable and a powerbank is in fact very small and compact in this context. I can leave it anywhere on the desk on even on the supply. It looks nice too. You can think it like an ornament on your desk. Someone here even leaves their chair in garage, who cares about that tiny 'extra' space?
If I had a spare PL8 and had my hand control, maybe I would make an external BT. It must be done by myself, I could not trust my dad or anyone else in this stuff. And I would only do it for fun. Because the internal BT does not give me much advantage over the external one.
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 02:39by expresso
good job
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 03:58by snaker
The BT (internal or external) is really useful for us. It is regrettable that there are too few members here have it. I only count 3 BM, Irving and mine. Is there anyone else?
About the prototype board that I posted above. If it is done as a PCB (printed circuit board), the stuff of making a BT internally or externally becomes trivial. Because all you have to do is soldering 10 legs into 10 holes on the PCB. For those who prefer internal BT, there are also volt regulators made for PCB (like in the pic underneath).
I tried to estimate the cost for a load of 20pcs PCB through a site of a company in VN who offers service to make PCB. It is only around $15, so less than $1/1 PCB. A friend told me in China, it is even cheaper.
https://machinchatluong.vn/
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 04:00by expresso
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 08:59by snaker
Some pícs above the prototype board. Do you see it is very simple? Do not leave the color tracks in the pic in my previous post scare you. They are not complicated as they look. If you go with a PCB, all those tracks are already printed on the board. You only need to solder components' legs into the right holes on the PCB.
Re: Electronic experts - BLUETOOTH
Posted:
01 Mar 2021, 11:24by Burgerman
Well if it works for you!
But fit it inside, and you only need the blue BT board. No wires or anything external. nothing trailing. And its powered interally. All invisible and self contained and neat. And actually easier/simpler to do. But both ways obviously work.
Re: Electronic experts - BLUETOOTH
Posted:
02 Mar 2021, 09:09by peterik
Is the BLUETOOTH module also able to control the cart electrically via android?
and can you buy it for how much?
Re: Electronic experts - BLUETOOTH
Posted:
02 Mar 2021, 10:07by snaker
BT module is simply to transmit data. It is not able to control anything. In VN, HC-06 costs around $3-$5 depending on sellers. Some claim they sell genuine ones and the price is a bit higher. But it is hard to see anything better.
Re: Electronic experts - BLUETOOTH
Posted:
03 Mar 2021, 06:47by swalker
snaker wrote:It is regrettable that there are too few members here have it. I only count 3 BM, Irving and mine. Is there anyone else?
I put together an external BT for my PL8. It works great.
I knew before I started that range would be a problem. The wheelchair lives two rooms away and there are walls the signal has to make it through.
In practice, the range from the wheelchair to the computer is just too great. So, I don't use the BT connection, though I know it would be handy to have.
When I need to know what my batteries are doing, I set up a laptop and use it to control the PL8. Otherwise, I simply rely on the PL8 display.
Steve
Re: Electronic experts - BLUETOOTH
Posted:
03 Mar 2021, 08:54by snaker
swalker wrote:I knew before I started that range would be a problem. The wheelchair lives two rooms away and there are walls the signal has to make it through.
In practice, the range from the wheelchair to the computer is just too great. So, I don't use the BT connection, though I know it would be handy to have.
How far from you or your computer to your chair in case it lives 2 rooms away?
Re: Electronic experts - BLUETOOTH
Posted:
03 Mar 2021, 10:31by Burgerman
BT modules range varies a lot. The antennas are all screwed up by being a bit of circuit board and a monopole. Some seem to have at least double the range of others. My laptop has about half the range of the D shaped tiny BT module in my PC. From my laptop I charge through my 9 inch thick bedroom wall in the kitchen no problem though. From the PC it goes to the front of the house, several walls. Beware steel radiators! Doesent like those in the way.
Also BT has an extremely narrow bit of the spectrum. So if anything else like your or your neibours wifi uses that bit too, it works badly.
This page may be very useful.
https://blog.nordicsemi.com/getconnecte ... ooth-range
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 02:45by ex-Gooserider
I believe it is also possible to have a sort of Bluetooth network w/ intermediate devices so that you can send / rcv from device A to device B, and then have device B connect to device C, and so on.... I haven't done this, but I am pretty sure I've seen it described.
ex-Gooserider
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 03:45by swalker
snaker wrote:How far from you or your computer to your chair in case it lives 2 rooms away?
About 25 feet with a total of 4 walls in the way.
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 04:24by snaker
25 feet = 8m? It is rather a very short range, your PC/laptop/phone should be able to control the charger. If they cannot, maybe the problem relies on the bluetooth adapters inside them. HC-06 broadcasts far 100m in open space, it should work fine in the 20m radius even through multi walls.
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 08:29by snaker
I was told genuine HC-06 was discontinued. I am looking for an alternative and found this jdy-40 (a well-known Chinese brand). On banggood.com, it costs $5 but its real price is a lot cheaper. In VN, it's sold at around $1. On taobao, it's even cheaper about $0.5.
https://sea.banggood.com/JDY-40-2_4G-Wi ... 23988.htmlIts specs are very similar as HC-06. Comparing to HC-06, it's smaller and has a better working range (120m vs 100m). The downside is that it consumes a bit more energy and only supports low input voltage 2.2-3.6V.
I intend to buy some for testing. I have questions:
1. To power JDY-40 by a 5V source, can I put 3 diode that are connected in serial at the positive? My purpose is to reduce 5V input down to 5 - (3 * 0.6) = 3.2V. Will this solution work?
2. JDY-40 supports various "transmit power" from -25db to 12db (default is the max 12db). I am curious what does "transmit power" mean? If the purpose is to keep signal as strong as possible, should I keep using the default 12db or change it to a lower value?
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 09:17by Burgerman
It should. Diodes vary a bit tough. And the voltage will drop a litte under load so measure while connected.
Its db output power. So 20dbm would be around 100mW. Each 3db is half or double. So 17dbm output is 50mw. And so 14 is 25mW. So 12 is 15mW. Not much. The only advantage of lowering it is to take less power to run. And get less range.
One thing is that they use a folded up antenna on the board. A short bit of wire about 21mm long givs better range.
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 17:23by expresso
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 17:32by woodygb
1. To power JDY-40 by a 5V source,
...Buy a USB to serial UART interface that supplies 3.3v.
Re: Electronic experts - BLUETOOTH
Posted:
09 Mar 2021, 19:40by Burgerman
BT 5 gives 4x the range of the others. As long as thats at both ends.
Re: Electronic experts - BLUETOOTH
Posted:
10 Mar 2021, 01:54by snaker
expresso wrote:one is 6 and other is 5 - are any of these any good ?
HC-05 has 2 more pins and more functions that we do not need. But it can be used same as HC-06.
Re: Electronic experts - BLUETOOTH
Posted:
19 Mar 2021, 02:04by snaker
This is my new BT box. This one comes with battery and charger
